meas urement of b s oscillations at cdf
DESCRIPTION
Meas urement of B s oscillations at CDF. Giuseppe Salamanna Univ. di Roma “La Sapienza” & INFN Roma for the CDF Collaboration. BEACH 2006 July 2006 Lancaster (UK). Outline. - PowerPoint PPT PresentationTRANSCRIPT
Giuseppe Salamanna Univ di Roma ldquoLa Sapienzardquo amp INFN Romafor the CDF Collaboration
BEACH 2006 July 2006 Lancaster (UK)
Measurement of Bs
oscillations at CDF
2
OutlineMotivations ΔMs and the Unitarity Triangle Analysis details Trigger and reconstruction Lifetime measurements and biases Flavour tagging(Some) Statistical details and expected significance Results for ΔMs Interpretation and derived constraints
Paper submitted to PRL hep-ex0606027
3
Why ΔMs Observation of a quantum phenomenon flavour oscillations via a ΔF = 2 Box diagram
222
222
||6
)(tbtqBBB
tWFq VVBfm
xSmGM
qqq
b s
bs
0sB
0sB u c t u c t
tsV
tbV
tbV
tsV
W
W
bullThe only relevant diagram has b coupling with top
bullNew (s)particles in the loop
Form factors and B-parameters from Lattice calculations have high uncertainty rarr Vtd known only at ~15 level
Mixing involves CKM elements rarr measuring ΔMq constraintsthe unitarity triangle
4
UT and constraint from mixing
ΔMd onlyLimit on ΔMs ΔMs ΔMd
From lattice
bull Ratio equiv ξ2 is better
calculated than single factors
bull ξ = 1210 + 0047-0035
(MOkamoto hep-lat0510113)
clubs Measuring ΔMs ΔMd
returns Vts Vtd with ~4 error from theory
ss
dd
Bf
Bf2
2
UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)
bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1
ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos
5
Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)
Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic
Flavour tagging Tag the flavour of the mixing B candidate using both
correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)
Want to measurehellipso how
6
Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood
tMDAeL ttsig cos1
1
Fit A for fixed ΔM
A consistent with1 if mixing detected at a given ΔM
0 if no mixing at a given ΔM
Limit where A+1645σA = 1Sensitivity 1645σA = 1
Example of amplitude scanWorld Average Fall lsquo05
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
2
OutlineMotivations ΔMs and the Unitarity Triangle Analysis details Trigger and reconstruction Lifetime measurements and biases Flavour tagging(Some) Statistical details and expected significance Results for ΔMs Interpretation and derived constraints
Paper submitted to PRL hep-ex0606027
3
Why ΔMs Observation of a quantum phenomenon flavour oscillations via a ΔF = 2 Box diagram
222
222
||6
)(tbtqBBB
tWFq VVBfm
xSmGM
qqq
b s
bs
0sB
0sB u c t u c t
tsV
tbV
tbV
tsV
W
W
bullThe only relevant diagram has b coupling with top
bullNew (s)particles in the loop
Form factors and B-parameters from Lattice calculations have high uncertainty rarr Vtd known only at ~15 level
Mixing involves CKM elements rarr measuring ΔMq constraintsthe unitarity triangle
4
UT and constraint from mixing
ΔMd onlyLimit on ΔMs ΔMs ΔMd
From lattice
bull Ratio equiv ξ2 is better
calculated than single factors
bull ξ = 1210 + 0047-0035
(MOkamoto hep-lat0510113)
clubs Measuring ΔMs ΔMd
returns Vts Vtd with ~4 error from theory
ss
dd
Bf
Bf2
2
UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)
bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1
ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos
5
Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)
Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic
Flavour tagging Tag the flavour of the mixing B candidate using both
correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)
Want to measurehellipso how
6
Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood
tMDAeL ttsig cos1
1
Fit A for fixed ΔM
A consistent with1 if mixing detected at a given ΔM
0 if no mixing at a given ΔM
Limit where A+1645σA = 1Sensitivity 1645σA = 1
Example of amplitude scanWorld Average Fall lsquo05
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
3
Why ΔMs Observation of a quantum phenomenon flavour oscillations via a ΔF = 2 Box diagram
222
222
||6
)(tbtqBBB
tWFq VVBfm
xSmGM
qqq
b s
bs
0sB
0sB u c t u c t
tsV
tbV
tbV
tsV
W
W
bullThe only relevant diagram has b coupling with top
bullNew (s)particles in the loop
Form factors and B-parameters from Lattice calculations have high uncertainty rarr Vtd known only at ~15 level
Mixing involves CKM elements rarr measuring ΔMq constraintsthe unitarity triangle
4
UT and constraint from mixing
ΔMd onlyLimit on ΔMs ΔMs ΔMd
From lattice
bull Ratio equiv ξ2 is better
calculated than single factors
bull ξ = 1210 + 0047-0035
(MOkamoto hep-lat0510113)
clubs Measuring ΔMs ΔMd
returns Vts Vtd with ~4 error from theory
ss
dd
Bf
Bf2
2
UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)
bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1
ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos
5
Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)
Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic
Flavour tagging Tag the flavour of the mixing B candidate using both
correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)
Want to measurehellipso how
6
Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood
tMDAeL ttsig cos1
1
Fit A for fixed ΔM
A consistent with1 if mixing detected at a given ΔM
0 if no mixing at a given ΔM
Limit where A+1645σA = 1Sensitivity 1645σA = 1
Example of amplitude scanWorld Average Fall lsquo05
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
4
UT and constraint from mixing
ΔMd onlyLimit on ΔMs ΔMs ΔMd
From lattice
bull Ratio equiv ξ2 is better
calculated than single factors
bull ξ = 1210 + 0047-0035
(MOkamoto hep-lat0510113)
clubs Measuring ΔMs ΔMd
returns Vts Vtd with ~4 error from theory
ss
dd
Bf
Bf2
2
UP TO WINTER lsquo06bullΔMs ge 166 ps-1 (LEP+SLD+Tevatron I and II)
bullExpected value (UT fit utfitroma1infnit) ΔMs (SM) = 215 plusmn 26 ps -1
ΔMs in [167 269] 95 CLclubs LARGER ΔMs could indicate NP contribrsquos
5
Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)
Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic
Flavour tagging Tag the flavour of the mixing B candidate using both
correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)
Want to measurehellipso how
6
Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood
tMDAeL ttsig cos1
1
Fit A for fixed ΔM
A consistent with1 if mixing detected at a given ΔM
0 if no mixing at a given ΔM
Limit where A+1645σA = 1Sensitivity 1645σA = 1
Example of amplitude scanWorld Average Fall lsquo05
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
5
Final stateReconstruct final states from both Semileptonic (high statistics but missing kinematics) and Hadronic (fully reconstructed best ct resolution)
Lifetime measurement Hadronic decay length measured with better resolution than Semileptonic
Flavour tagging Tag the flavour of the mixing B candidate using both
correlation with fragmentation tracks AND flavour of other b (incoherent b-b production)
Want to measurehellipso how
6
Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood
tMDAeL ttsig cos1
1
Fit A for fixed ΔM
A consistent with1 if mixing detected at a given ΔM
0 if no mixing at a given ΔM
Limit where A+1645σA = 1Sensitivity 1645σA = 1
Example of amplitude scanWorld Average Fall lsquo05
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
6
Amplitude ScanIntroduce ldquoAmplituderdquo in Likelihood
tMDAeL ttsig cos1
1
Fit A for fixed ΔM
A consistent with1 if mixing detected at a given ΔM
0 if no mixing at a given ΔM
Limit where A+1645σA = 1Sensitivity 1645σA = 1
Example of amplitude scanWorld Average Fall lsquo05
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
7
BS
Se
DS tsM
A
2
)(22
21
Measurement significanceThe expression of the statistical Significance of a mixing measurement is given by
Signal
(b-flavour at decay tagged)
Fraction of S withinfo also on flavour at creation
Experimental time resolutionexponentially dilutes a measurement
Trigger-challengeto collect Ssuppressing B
Significance exponentially reduced at higher ΔMs hellip
hellip|Vts| gtgt |Vtd| Ms ~40Md
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
8
Final states selection and yields
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
9
Hadronic signalsL = 1 fb-1
N(Bs) asymp 3600
)(
)(00
0
ss
ssss
DB
DDDB
ldquoSatellitesrdquo
(Not used in this analysis)
Bs0rarr Ds
- (3)π+ (Ds
- rarr φπ- φ rarr K+ K-)Bs rarr Ds π Ds rarr φ π
1570 plusmn 43
Bs rarr Ds π Ds rarr K0 K- 857 plusmn 32
Bs rarr Ds π Ds rarr 3π 612 plusmn 37
Bs rarr Ds 3π Ds rarr φ π 493 plusmn 37
Bs rarr Ds 3π Ds rarr K0 K- 204 plusmn 26
bullFully reconstructed decays triggered on at CDF only requiring 2 tracks with
bull d0 gt 120 μm (τ(B)asymp15ps)
bullPt gt 55 GeVc
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
10
Semileptonic signals
Bs0rarr Ds
-() ℓ+ν X (Ds
- rarr φπ-)bullMissing Pt rarr No Bs mass peakbullUse Ds mass signalsbullUsing M(lDs) helps bkg rejectionbullCharge correlation between ℓand DsbullBkg also from Right Sign (~15)
bullDs + fake lepton from PVbullBsd to DsDX D to ℓ νXbullcc background~37000 semileptonic Bs candidates
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
11
Lifetime measurement
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
12
Hadronic Lifetime Results
Modecτ [μm]
(stat only)
B0D- + 4911 plusmn 51
B-D0 - 4521 plusmn 51
BsDs() π 461 plusmn 12
World Average (HFAG06)cτ(B+) = 4911 plusmn 33(stat) μmcτ(Bd) = 4587 plusmn 27 μmBsrarrFlavour specificcτ(Bs) = 432 plusmn 20 ps
bullDetailed simulation to correct for trigger bias
on the selection of the B decay lengthbullSyst on trigger efficiency negligible
for mixing measurements
Excellent agreement
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
13
Effect of proper time resolutionAmplitude of mixing asymmetrydiluted by a factor 2
2
)( t
t
M
eD
2
20
p
ct pctct
Vertex resolution(constant)
Momentum resolution
(~ct)
bullCalibrated on large D+ data samples combined withprompt tracks to mimic B0-like topologies
bullCalibrate by fitting for lifetime of B0-like decays
osc period at Ms = 18 ps-1
Hadronic-like
Semileptonic-likeltσppgt asymp15
CDF II
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
14
Flavour tagging
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
15
Combined tagging powerOpposite Side Taggers (OST) tag the other b-hadron in the event using e and μ from decay and jet charge Combine OST exclusively Calibrate Combined OST on samples of B+ and Bd (by measuring ΔMd)Add Same Side Kaon Tagger independently
εD2 Hadronic ()εD2 Semileptonic
()
Muon 048 006 (stat) 062 003 (stat)
Electron 009 003 (stat) 010 001 (stat)
JQSecVtx 030 004 (stat) 027 002 (stat)
JQDisplrsquod trk
046 005 (stat) 034 002 (stat)
JQHigh pT 014 003 (stat) 011 001 (stat)
Total OST 147 010 (stat) 144 004 (stat)
SSKT 35 05 (syst) 40 06 (syst)
Efficiency
Dilution = 1-2bullmistag rate
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
16
Main ldquoboostrdquo is from SSKT Exploits the charge correlation between the b flavour
and the leading product of b hadronization Close to trigger B large acceptance SS Kaon Tagging exploits PID over wide momentum
range rarr use a combined TOF+dEdx likelihood ratio Dilution depends on the fragmentation process rarr
cannot calibrate using Bd and B+ rarr Need to estimate D from MC Extended MC-data comparison on quantities related to
fragmentationThen test predictions on data for other species (B+ and
Bd) and add systematics on agreement accordingly for usage with Bs
Bs
K- K0
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
17
RESULTS
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
18
Amplitude Scan (hadronic+semileptonic)
AA (173 ps-1) = 37
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
19
SensitivityCDF sensitivity compared to WA
CDF II 1 fb-1 -045 plusmn 023 (258 ps-1)
This sensitivity reached withbull1 fb-1
bullAddition of SSKTbullImproved σct fitting model
Use the Likelihood Ratio -Δlog(L) = -log[ L(A=1) L(A=0) ] to evaluate the probability p of null experiment (bkg fluctuations)
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
20
Significance of the peak
From data ndashΔlog(L)MIN = -675
Randomize tags ~50k times on data and
calculatehellipP-value = 02
Significance gt 3σrarr assume that peak IS real mixing signal
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
21
FinallyhellipΔMs
bullContribution of hadronic modes essential due to better
ct resolution at high ΔMs
σ(ΔMs) ΔMs ~ 002ms in [1701 1784] ps-1 at 90 CLms in [1696 1791] ps-1 at 95 CL
bullSystematics low and under controldominated by uncertainty on the absolute scale of the decay-time
measurement
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
22
From ΔMs information on UT
bullCompatible with SM within 1σ
bullFrom measurement and chosen inputs(m(B0)m(Bs) = 09830 ΔMd = 0505 plusmn 0005 ps-1
from PDG06 and ξ = 1210+ 0047
-0035 hep-lat 0510113)
we infer the value |Vtd||Vts| = 0208 +0001
-0002 (exp) +0008 -0006 (th)
bullConstraint on CBsCBs = Ms
SM+NPMsSM = 101 033
[033204] 95 CL (UTFit utfitroma1infnit)
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002
23
ConclusionshellipbullCDF finds signature consistent with Bs oscillations bullProbability of fluctuation from random tags is 02 bullConstraints to UT
ρ = 0193 plusmn 0029 (was 0240 plusmn 0037 )η = 0355 plusmn 0019 (was 0333 plusmn 0022 ) (UTFit)
hellipand perspectivesbullInclusion of partially reconstructed decaysbullRefinement of fully reconstructed mode selections to gain eventsbullNew OS Kaon Tagger in place εD2 = 023 plusmn 002