Experimental Status of Flavor Physics:Snapshot From CKM2005 (March 05)
Vivek Sharma
University of California, San Diego
Special Thanks : Andreas Hocker, Kevin Pitts, Ben Grinstein,
Zoltan Ligeti, Bob Kowelewski, and Daniele del Re
What This Talk Won’t Cover
• Flavor physics is a vast subject with many subtleties • For a snapshot of this field, see the presentations,
discussion and roundtable during CKM2005 workshop(s) at UCSD in March 2005– http://ckm2005.ucsd.edu/
• In this review I will not cover – Light quark results (Focus of this workshop)– Impressive strides made in (Heavy) flavor theory– “Grade” the “utility” of Lattice results on HF
Parameters• http://ckm2005.ucsd.edu/agenda/wed1/bernard.pdf
– Important experimental tests of theory of flavors– Discussion of future (super) facilities
Measurements related to Overconstraining the “db’ Unitarity triangle• Facilities for Heavy Flavor Studies : status • Measurements of sides of the Unitarity Triangle
– Vcb– Vub– Vtd & Vts : Electroweak penguin and BS Mixing
• CP Violation in B Decays and measurements of CKM angles– Direct CPV in B Decays– Gold plated measurement of with B J/ K0
– Penguin Nuisance in measurement of = --– Quest for the angle in B DK Direct CPV
• Profile of the Unitarity Triangle Circa CKM2005• Penguin Lust : CP Asymmetries in s-Penguin B Decays and
searches for new physics
Outline of This Talk
Semileptonic B Decays
The Cabibbo Kobayashi Maskawa Matrix VCKM
=
2 31-λ /2 λ Aλ (ρ- )V V Vud us ub2 2 4V= V V V -λ 1-λ /2 Aλ +O(λ )cd cs cb
3 2V V V Aλ (1-ρ- ) -Aλ 1td ts tb
iη
iη
Experimental goal is precise measurements of magnitudes and phases
= 0.226 ± 0.002A= 0.85 ± 0.05É= 0.22 ± 0.09¿= 0.33 ± 0.05
• In the SM, the CKM matrix elements Vij describe the electroweak coupling strength of the W to quarks
– CKM mechanism introduces quark flavor mixing
– Complex phases in Vij are the origin of SM CP violation
• In the Wolfenstein parametrization
Mixes the left-handed charge –1/3 quark mass eigenstates d,s,b to give the weak
eigenstates d’,s,b’.
Triangles, Triangles, Triangles
Triangles, Triangles, Triangles
Unitarity orthonormality of rows 2 *V =1, & colu V V =0
iα iαmns
iβi i
Unitarity Triangles: The “db” triangle For Bu/d System
2
1
3
*V Vtd tbarg *V Vud ub
*V Vcd cbarg *V Vtd tb
*V Vud ubarg*V Vcd cb
Angles of Unitarity Triangle
*ub
† * *ud tc cb tbddV V=1 V +V VV + VV =0
*V Vts tbNote: For B meson: arg ,
S S *V Vcs cb
*V Vcs cdFor K meson:
Both angles are tiny in comparis
argK *V V
us ud
on
Facilities for Heavy Flavor Physics
BaBar@PEP-II
Belle @KEK-b
D0 & CDF @ TeVatron CLEO-c @ CESR
Era of The Factories: Unprecedented Luminosities !
BELLE
CDF & D0
Ldt >800pb-1
Ldt >450 fb-1
Ldt >250 fb-1
Beam Energy (GeV)
CLEO-c Ldt>60pb-1
(3770)
’
Ebeam
Cleo-C Detector Taking Data at e+e-(3770)DD
K-
-
e+
K+
-1
-1s s
-1 (3770)
Year 1 goal: 3 fb @ (3770) ( ) ( 10increase)
Year 2 goal: 3 fb
Accu
@ ~ 41
mulated ~60pb @
3 year CL
40 MeV D D threshold
EO-c program starts April 2005
( 130 BES)
Year 3 goal: 1 billion J/ ( 20 BES
DD
)
Complete Survey of Charm Meson Decays
See D. Asner’s talk on Cleo-c results and prospects
• Absolute Charm Branching fractions
• Charm decay constants fD
• Rates and FF in Semileptonic decays• Strong phases in hadronic D decays
critical for CPV measurement in B decays
• DD Mixing and CP violation
CDF& D0 Equipped with Silicon Inner TrackingIntermediate Silicon Layers of CDF
CDF
D0
Heavy Flavor Physics at CDF& D0
• Silicon gives the “lifetime optic” to CDF & D0, enables lifetime based analyses and trigger…..now proven to work !
• All species of heavy mesons and baryons are produced
• Goals
– Map out weak decay of all b hadrons, including b and Bc
– Exploration of the Bs meson system• Width difference • Bs Oscillations (take over from LEP/SLD)
• CPV studies (Bs mixing and luminosity willing)
– Searches for rare decays enhanced by NP• B + -
• Electoweak penguin etc
Belle and Babar: Dominating B Physics Since ‘99
e
e
b
b
(4 )S
0B0B
Enough energy to barely produce 2 B mesons, nothing else!
B mesons are entangled Need for Asymm energy collisions
Excellent
Tracking, PID
Radiative Penguin Decays: Window to NP
See Hitoshi Yamamoto’s talk for Details
b sb s l+l
FCNC Via Electroweak Loops & New Physics
10*
i
7 7 9
eff1
Information about heavy particles and new physics encoded in
short distanc
4Effective Interaction
e (Wilson) coeff C
C most important fo
Hamiltonian: ( ) ( ) (
r b s ; C , C
2
(Z)
)tb ts i ii
GH V V C O
i
+
QCD b
10
Hadronic matrix elements of operators O contain all long-distance
QCD interaction effects
Long-distance expansion in powers of ( /m ), Hea
, C important for
vy Quark
Effective
(W
Theory
s
Q
b
,
)
CD-factorization, Lattice...etc
Experimentally probed via measurements of decay Rate and Asymmetry
? ? ?
Measurement of Inclusive b s Decay Rate
BaBar sum of exclusiveBaBar Inclusive, E > 1.9 GeV
Theory uncertainty could improve to ~5% (NNLO) ??
Belle Inclusive, E > 1.8 GeVCLEO Inclusive, E > 2.0 GeV
Experimental precision will keep pace (500 fb-1)
Belle
?E> 1.8 GeV
SM
Data agrees with SM (10%)
Rate of b d• Decay CKM-suppressed (|Vtd /Vts| ) w.r.t. b s; sensitive to |Vtd|• Inclusive b d measurements background challenged !
– b s 20 background ! Needs K+,KS and KL veto
• Exclusive processes are current exptal target: B ()– Theor. estimate imprecise B(B () ) [0.5-2.0]10-6 : Ali, Buchalla etal
– Ratio R(/K*) reduces theory error, estimates |Vtd /Vts|
BaBar Belle
6Br(B ( , ) ) 1.2 10 @90%CL 6Br(B ( , ) ) 1.4 10 @90%CL
“ At the verge of observation, Central Values in SM range”
Constraint On |Vtd /Vts| Compete with Bs Mixing
Inclusive Rate Of b s l+l
AFB sensitive to relative signs ofWilson coefficients : measurably large
Ali et al. PRD 66,034002(2002)
NP
)90()90(
)90()90()ˆ(
2
2
NN
NN
m
qsA
bFB
FB Asymmetry in b sl+l As Future Probe of New Physics
B
forwardbackward
Lepton pair CM
Forward–backward asymmetry (AFB)
2 3( ) 10 in SMFB FBCPFB
FB FB
A B A BA q
A B A B
AFB AFB under CP: Sensitive to New Physics through Non-SM CPV phases
BaBar ACP=0.22 0.26(stat) 0.02(syst) Consistent with SM theory but Data limited Potential to rule out some NP scenarios (where AFB is of opposite sign w.r.t SM) with 500 fb-1
scenarios consistent with measured rate
First Investigations of Bs Oscillations at Tevatron (Following LEP &SLD Searches)
td
ts
VV
LEP-SLD Limit On Bs Oscillation
Amplitude scan MethodFit Mixing Prob D*A*cos(m t) at fixed mExpect A=1 for real m, 0 otherwiseSensitivity: m such that 1.645A =1
95% CL: m such that A+1.645A = 1
1Sensitivity : m 18.2 pss
195% CL Limit: m 18.2 pss
Using inclusive Bs Samples
Critical Requirements for Bs Oscillation Measurement
1. Large reconstructed B sampless
(a) B D X (large samples but missing neutrino energy)s s
(b) B D ( small sample but has best propertime info)s sboth decay modes provide decay time fla
2. Flavor tag at production time (B or B )s s Often the "other B " is not within acceptence ! + So far CDF &D0 use only "Opposite-side" B flavor tag
2 (Ineffi
vor t
cient, Q= D 1.4% compat
g
i
a
ed w
s
th BaBelle)
m p
3. Precise proper time measurementL mxy B ct= Lxy pT
....not great for SL sample ( )
crucial for fast oscillations
B T ctct Lp pxyT10
T( m )
Bs Samples at Tevatron
Ds+ D++
1.420 0.043 0.057psBs
900 Bs Ds
with impact parameter trigger
5153 signal
This is the future
Tevatron Limits On Bs Oscillation
m > 7.9ps-1 @95% CL Sensitivity : m =8.4ps-1
CDF
Good first attempt to get in the game (Bs mixing is difficult!!)
But must improve not just in dataset but also tagging and propertime resolution
World limit (LEP/SLD) unchanged
Measurement of |Vcb| & |Vub| from Inclusive Semileptonic B Meson Decays
Vcd
*Vcb
Vud
*Vub
See Hitoshi Yamamoto’s talk for Details
Inclusive Semileptonic Decays: The Big Picture
*D
,...,
,,22G
cb mm
|| cbV
|| ubV
Shape
Rate
Inclusive El spectrum
2|| cbV
2|| ubV
2|| cbV
El[GeV]
Shape
Rate for Mx<1.55
Inclusive Mx spectrum
(log-scale)
B
X
|Vxb|2
Inclusive Approach Using OPE• Intimate knowledge of QCD is required to go from partonic
process to the hadronic states
• Given mb >> QCD , OPE used to describe inclusive rates in terms of |Vcb|, mb and a few nonperturbative matrix elements that enter at the order of (QCD/mb)2 and higher orders
• One extracts these parameters from a global fit to
– Inclusive rate, lepton energy (Eℓ) & hadron mass (mX) moments
0B
dM
1
E dM
d
1( 2,3)
i
i
E M dM i
d
( 1,2,3,4)iXX
i
m dM i
d
Partial branching fraction
Lepton energymoments
Hadron massmoments
experimentalobservables
Integrations are done for Eℓ > Ecut, with Ecut varied in 0.6–1.5 GeV
Fit Parameters in OPE Expansion
Calculation by Gambino & Uraltsev (hep-ph/0401063 & 0403166) Kinetic mass scheme to Eℓ moments
mX moments
8 fit parameters
8 moments available with several Ecut
Sufficient degrees of freedom to determineall parameters without external inputs
Fit quality tells us how well OPE works
cbV bm cm 2
2G
3D
3LS( )cB X B
kinetic
chromomagnetic
Darwin
spin-orbit
2(1/ )bmO
3(1/ )bmO
3(1/ )bmO2( )sO
( )sO
BABAR PRL 93:011803
Example OPE Fit To BaBar Semileptonic Spectra
mX moments
Eℓ moments
● = used, ○ = unusedin the nominal fit
Red line: OPE fitYellow band: theory errors
BABAR
2/ndf = 20/15
BABAR PRL 93:011803
Remarkable agreement between data and theory !
OPE Fits to BaBar Inclusive SL Data
and consistent with B-B* mass splitting and QCD sum rules and the scale of consistent with theoretical expectations
Remarkable agreement between data and theory
s
s
s
3exp HQE th
exp HQE
exp HQE
exp HQE
2 2exp HQE
2exp HQE
(41.4 0.4 0.4 0.6 ) 10
(10.61 0.16 0.06 )%
(4.61 0.05 0.04 0.02 )GeV
(1.18 0.07 0.06 0.02 )GeV
(0.45 0.04 0.04 0.01 )GeV
(0.27 0.06 0.03 0.0
cb
c
b
c
G
V
m
m
B
s
s
s
2
3 3exp HQE
3 3exp HQE
2 )GeV
(0.20 0.02 0.02 0.00 )GeV
( 0.09 0.04 0.07 0.01 )GeV
D
LS
2
3LS
kinetic mass scheme with = 1 GeV
Uncalculatedcorrections to
2 2G 3
D
PRL 93:011803
|Vub| From Inclusive bu l Spectrum
|Vub| can be measured from
The problem: b → cℓv decay
2
2
( ) 1
( ) 50ub
cb
Vb u
b c V
E
b c
b u
22 5
2( )
192F
u ub b
Gb u V m
Must suppress 50× larger background e.g. using kinematic differences (mu << mc) or particle identification (D*, Kaon content)
No perfect observable, All must deal with theory imprecision
Vub From Inclusive Measurements • Experimental requirements in bul signal extraction severely
“chops” and reduces the phase space in SL decay
• OPE does not provide predictions of differential rates: poor convergence in regions where bcl decays are kinematically forbidden
– Non-perturbative shape functions (SF) needed to calculate the extrapolate to full bul spectrum (rate)
• Theoretically, only rough features (mean, rms) of the shape functions are known but detailed shape not constrained
Belle E
1st and 2nd moment of SF determined
Use correspondence betweenPhoton spectrum in bs and Lepton energy spectrum in bul
Limited by experimental imprecion in Knowledge of the full photon spectrum
|Vub| From Inclusive b u l Observables
Example: BaBar Results at CKM2005
See Hitoshi Yamamoto’s Talk For Details & BaBar+Belle Averages
Bottomline: Vub measurements approaching 10% precision
BABARexcl(untagged)
Snapshot of measurements (’04)
CP Violation in B DecaysMeasurements of Angles of UT Triangle
Observation of Direct CPV in B0K- +
2 iSM amplitude e T P
sinKA
• Loop diagrams from New Physics (e.g. SUSY) can modify SM asymmetry
• Clean B mode with “large” rate :• CP Asymmetry measurement is a « Counting Experiment »
0 618.2 0.8 10 BF B K
T P
BaBar & Belle : Observation of Direct CPV in B DecayBaBar & Belle : Observation of Direct CPV in B Decay
0.133 0.030 0.009 AK
BABAR
0
0
910
696
n B
n K
K
B
AK = -0.101 0.025 0.005
Signal=2139 53
Combined BaBar & Belle significance = 5.7
Establishes CPV not just due to phase of B Mixing (M12)
Theoretical (npQCD) uncertainties insufficient to prove or rule out NP
Belle
CPV In Interference Between Mixing and Decay
0 0Neutral B Decays into CP final state accesible by both & decays
Interference described by CP
CP CP
CP
f
f ff
CP
q A
p
f B
A
B
+
2
+
2
B0
B0
B0
fcpB0
fcpB0
B0
fcpfcp
CP asymm. can be very large and “cleanly” related to CKM angles
0B
fiCPA e
CPf
0B
12
2 Mi
M
ie
fiCPA e
Requires time dependent measurement of CP Asymm.
Cartoon of (4S)B0 B0 Evolution & Decay
Time-dependent CP Asymmetry Due to Interference in Mixing and Decay
0 0
00
cos( ) sin( )
CP
P
CP
C
phys CP phys CP
f
physphys CP
ff
CP
B t f B t fA t
B t f B
C mt S
t f
mt Phase of mixing
CP
CP
CP
ff
f
Aqλ
p A
2 ie
Amplitude ratio
2
2
1 | |0
1 | |
CP
CP
CP
ff
f
C 2
2ImIm
1 | |
CP
CP CP
CP
ff f
f
S
(for single weak decay amplitude)
CPV In Interference Between Mixing and Decay: B0 J/K0
S
S
S
*cb cs*cb c
*cs c
* *ψKB tb cb cd
ψK *B ψ
d*tb td td
* *tK tb cb t
*cs b cd dd ts cd
q A V V Vλ = =- =-
p A
V V
V V V
V V
V
V V V
V V V VV V 1λ
β)sin(2)Im(λ
S
S
ψK
ψK
L SψK ψKλ λ
CP = -1 (+1)
for J/K0S(L)
2ie
0 /,/ 1 sin 2 sin( )t
S L CPB J K e mt
0 /,/ 1 sin 2 sin( )t
S L CPB J K e mt
0B
fiCPA e
CPf
0B
12
2 Mi
M
ie
fiCPA e
B Charmonium Data Samples
CP sample NTAGpurity ηCP
J/ψ KS (KS→π+π-) 2751 96%
J/ψ KS (KS→π0π0) 653 88%
ψ(2S) KS (KS→π+π-) 485 87%
χc1 KS (KS→π+π-) 194 85%
ηc KS (KS→π+π-) 287 74%
Total for ηCP=-1 4370 92%
J/ψ K*0(K*0→ KSπ0) 572 77%
J/ψ KL2788 56%
Total 7730 78%
MES [GeV]MES [GeV]
ΔE [MeV]
J/ψ KL signalJ/ψ X backgroundNon-J/ψ background
BABAR
(227 ) M BB(227 ) M BB
(ηCP = +1)
Sin(2 Result From B Charmonium K0 Modes
sin2β = 0.722 0.040 (stat) 0.023 (syst)
(cc) KS modes (CP = 1)
(PRL 89, 201802 (2002): sin(2β) = 0.741 ± 0.067 ± 0.034)
J/ψ KL mode (CP = +1)
(227 ) M BB(227 ) M BB
hep-ex/0408127
background
Sin(2 Result From B Charmonium K0 Modes
sin2β = 0.728 0.056 (stat) 0.023 (syst) (152 ) M BB(152 ) M BB
WA: sin2β = 0.726 0.037 (5% Measurement)
Belle
Measurement of Angle :
Dodging Penguins !
[ =-(+) ]
CPV in b u u d Process : B0 +-
* *
* *sin(2 )tb td ud ub
tb td ud ub
V V V VB
V V V V
Im
Neglecting Penguin diagram
*
(Penguins are large!) and
Weak Phase in Penguin t
depending on its rel
erm is arg( ) different from Tree so it wi
ative strength w.r.t
ll modify
Tree. td tbV V
Im
Reality in B0 +-, + -
Gronau& London: Estimate peng = eff - using isospin relations
Tree
,
,
Penguin,
,
Ratio of amplitudes |P/T| and strong phase difference
can not be reliably calculated!
If no penguins S ~ -0.34
Estimating Penguin Pollution in B0 +-, + -
A2
1
A2
1
00 AA
00A
00A
peng2
0
0
0 0
00 0 0 0
00 0
0
0
0
0
( )
( )
( )
( )
(
( )
)
A A B
A
A A B
A A B
A A B
A
B
A B
A
0 0 0 +- +0 0
0
0
B states can have I=0 or
B , and related by SU(
2; Gluonic Penguins co
2) Isospin relation between amplitudes A ,
ntribute only to I=0 ( I=1/2 ru
A an
B has only tree ampl
A
le
i
)
d
+0 -0tude | A | = | A |
00 0penguin
+0 000
0
+- 0
A and A to be very smalTo constrain by isospin analysis requires !
Go measure and constrain C , C , A A
l
,
Similarly for B system
Rates and Asymmetries in B0 0, B+ -
0 0 0BF(B ) is large
Isospin analysis not effective
Weak constraint on [67o -131o] with current statistics
openg 35 at 90% CL
B0 + - System As Probe of Has Nature’s “Blessing”
0 6
0
Br(B ) (30 4 5) 10 !!
Six times larger than Br(B )
Blessing # 1 Likelihood projection
Although 2 0’s make efficiency small
B0 + - System As Probe of
• Blessing # 2
• Blessing # 3
0
peng
oeff
0 0 0 6
Substantially smaller than B !
Much more amen
much better constraint on
| | 11 @68% C
able to Isospin ana
L
Br(B ) 1.1 10 @ 90%
l s
L
s
C
y i
0.021L 0.0
0
28f 0.97
Angular analysis shows that B
is almost 100% longitudinally polarized !
Pure CP-even final state
This greatly simplifies TD CPV analysis
8 0.014
bkgd
total
Helicity angle
eff|<11o @ 68%C.L.
TD CPV Measurement in B0 + -
Shown here are events from the Lepton and Kaon1 tagging categories only
0.080.14
0.0200.028
0.33 0.24
0.03 0.18 0.09
0.978 0.014
Long
Long
L
S
C
f
total likelihood
total background
617 52 signal events
Discerning
o o
100 13
[79 123 ] @ 90% CL
Br() (30±6) 10-6
Br() (26±6) 10-6
Br() <1.1 10-6
0.080.14
0.0200.028
0.33 0.24
0.03 0.18 0.09
0.978 0.014
Long
Long
L
S
C
f
16 o9
Putting it all togather
(101 )
B0 + -
Measurement of Angle
Requires Direct CPV in B Decays
See talk by Fernando Martinez-Vidal for Details
CP Asymmetry In BDK Decay
0K
Look for B decays with 2 amplitudes with relative weak phase
iV eub
Relative strength of the two B decay amplitudes matters for interference
Want rb to be large to get more interference Large CP asymmetry
0.1-0.3
from B±D0 K±: D0 KS + - Dalitz Analysis
2 2 2 ( ) 2 2 2 For : | | | ( , ) ( , )| i
bB A f m m r e f m m
2 2 2 ( ) 2 2 2 For : | | | ( , ) ( , )| ibB A f m m r e f m m
2 0 2 2 0 2 Defining ( ) ; ( ) S Sm M K m M K
2
( )ibr e
2
sKm
2
sKm
2
SKm
2
sKm
0 D 0 D
2A
Schematic view of the interference
0S
+ -B
Simultaneous fit to D K Dalitz distribution of
B info on and B r , data giv and ste rong phase s
B Samples : Belle (~250 fb-1)
Likelihood fits to the B->D(*)0 K(*) Dalitz Distributions
Combined
Analysesstatistics starved !
All CKM Angle Measurements On The - Plane
16 o9
15 o1
o
3
(23.2 1
(63
(101 )
.5)
)
and
187.2!
Putting All Observables On The - Plane
Beautifully consistentoverlap !
BUT !
Searching For New Physics In Penguin Decays of B Meson
<< Testing Vs “” >>
Compare sin2 with “sin2” from CPV in Penguin decays of B0
Both decays dominated by single weak phaseBoth decays dominated by single weak phase
b s
, ,u c t, ,g Z
tb tsV V
Penguin:
s
dd
s
Tree:
b
dd
W cbV
csV
0K
c /J
s0K
New Physics? 3
0 0 0, , ,
2
/ / /S L S L S L
icb csJ K J K J K
cb csB K
V Vq qe
p V V p
c
0 0 0, , ,
2~S L S L S L
itb tsK K K
tb tsB K
V Vq qe
p V V p
b ccs
b sss
?[charmonium]sin2 [ -penguin]sin2 s
0
-i2
In SM, interference between B mixing and dominant b sss (b suu)
[penguin amplitudes have no CKM phase]
Loop di
gives t
agrams s
he same CPV (due
ensitive to high
to e )
vi
as in b c
rtual mass scale
cs
s
NP coupling can bring in new phases that may cause deviation
sensitive to ne
s from expected
w physi
"si
cs
n2 "
Must be if one amplitude dominates
Ranking Penguin Modes by SM “pollution”B
ron
zeS
emiG
old
Go
ld
b
dg
t0B
d
ss
s
W 2~tb tsV V
0K
0', f
0K
b
dg
t
d
ss
s
W
0B
2~tb tsV V
b
dg
t0B
d
ds
d
W
2~tb tsV V 0 0, ,
0K
2( )
~ 5%
~ 5 10%
2( / )
~ 20%
2( (1 / ))qqf
b
dg
u0B
d
ss
W 4~ i
ub us uV V R e
4~ iub us uV V R e
W b
d
0B
d
uu
0', f
s 0K
0Ks
4~ iub us uV V R e
W b
d
0B
d
uu 0 0, ,
s 0K
Decay amplitude of interest SM PollutionNaive (dimensional) uncertainties on sin2
Note that within QCD Factorization these uncertainties turn out to be much smaller !
The « Golden » Penguin mode B0 K0
• Modes with KS and KL
are both reconstructed
0 0LB K0 0
SB K K K
114 ± 12 signal events 98 ± 18 signal events
full backgroundcontinuum bkg
(Opposite CP)
Plots shown are ‘signal enhanced’ through a cut on the likelihood on thedimensions that are not shown, and have a lower signal event count
0K
b
dg
t
d
ss
s
W
[ ],
CPK K
hep-ex/0502019 BaBar
CP analysis of ‘golden penguin mode’ B0 K0
0tagB
0tagB
0tagB
0tagB
S(KS) = +0.29 ± 0.31(stat) S(KL) = -1.05 ± 0.51(stat)
0
0
0.07 0.040.50 0.25
0.00 0.23 0.05
K
K
S
C
Combined fit result(assuming KL and KS have opposite CP)
Standard Model Prediction
S(K0) = sin2 = 0.72 ± 0.05
C(K0) = 1-|| = 0
0.9
0 0LB K0 0
SB K K K (Opposite CP)
K0
BaBar
The Semi-Gold penguin modes: B0 ’KS
• Large statistics mode
• Reconstruct many modes ’ + –, 0 , + –0
– KS + – ,00
B0 ’KS
819 ± 38 signal events
0 0 6BR( ) ~ 65.2 10B K
0 0 6recBR( ) ~ 14.9 10SB K
hep-ex/0502017
B0 ’KS
0
0
0.10.27 0.034
0.100.21 0.03S
S
K
K
S
C
sin2 [cc] @ 3.0
K0BaBar
Sin2b from bs penguins – Summary of All MeasurementsDiscrepancy in sin2 from charmonium and penguin is 3.7
All measurement
luminosity limited
SLAC/INT Workshop, Seattle 2005 A. Höcker – sin2eff with s-penguin decays
Summary of Experimental Program for sin 2eff
Mode CPTot. error
BelleL ~ 253 fb–1
Tot. error BABAR
L ~ 195-212 fb–1
Δ(SM) [in ]
Error estimate at 2 ab–1
Syste-matics
Max. central
value for 5 deviation at
2 ab–1
Quality[naïve
theoretical cleanliness]
K0 –1 0.34 0.26 – 1.9 0.10 small 0.22 ☻☻☻
’K0 –1 0.18 0.14 – 2.6 < 0.05 small 0.45 ☻☻(☻)
f0(980)K0 +1 0.42 0.29 – 1.3 < 0.12 Q2B 0.12 ☻☻
KSKSK0 ±1 0.71 0.36 – 1.4 < 0.16 vertex – 0.08 ☻☻☻
K+K–K0 ~+1 0.25 0.25 – 1.1 < 0.08 CP 0.31 ☻(☻)
0KS –1 0.60 0.32 – 1.4 0.13 vertex 0.07 ☻
K0 –1 0.66 0.36 – 0.6 < 0.15 small – 0.03 (☻)
0K0 –1 - - ? ? Q2B ? (☻)
KS +1 - - ? ? vertex ? -
Average - 0.39 ± 0.11 0.45 ± 0.09 – 3.7 < 0.034 ok 0.53 ☻☻
Summary Of Highlights in (Heavy Flavor) Physics
• Radiative Penguin decay rates conform to SM expectations (~10%). No sign of NP in rates and asymmetries
• Measurement of |Vcb| approaching 1% precision, |Vub| precision 10%
• Tevatron Bs Oscillation limits ms 7.9 ps-1 , expect rapid progress
• Precise measurement of CPV (sin2) in B K0 decay confirms the KM conjecture for CP violation CP Violation is not a tiny, it’s O(1) effect
• Direct CP Violation seen in B Kpi (rules out superweak in B sector)
• Direct measurements of UT angles :
• All CKM observables (sides and angles) give consistent picture
• The major surprise is possible discrepancy in sin2 measured in B Charmonium and B s-penguin decay modes
– The largest single discrepency is about 3 but the inconsistency when adding (?) all modes is about 3.7
– This could be a significant fluctuation !
– Or Penguins are hinting at Beyond SM physics• ONLY MORE DATA (being accumulated as we speak) WILL CLARIFY
• Check back in a few years!
16 o o 15 o(101 ) ; (23.2 1.5) ; (63 )9 13
Inclusive Semileptonic decays
*D
,...,
,,22G
cb mm
shape
|| cbV
uc ,
)( e
,eW
...,,,,,, (*)*** DDDDB
K
|Vcb|2, |Vub|2
|| ubV
Shape
Rate
Inclusive El spectrum
Semileptonic B decay
2|| cbV
2|| ubV
2|| cbV
HXbq
El[GeV]
Shape
Rate for Mx<1.55
Inclusive Mx spectrum
(log-scale)
Fit Consistency
OPE describes BABAR data very well 2/ndf = 20/15 Separate fit of Eℓ and mX moments agree
BABAR
BABAR PRL 93:011803
Radiative and Electroweak Penguin Decays of B Mesons
• FCNC process forbidden at Tree level, occur only thru induced loop effects
• Probe the underlying fundamental theory at quantum level sensitive to masses much higher than b quark (e.g. t quark)– Enable measurement of CKM elements Vtb, Vtd and Vts
• In Beyond SM scenarios, FCNC processes sensitive to loop effects of new particles such as Higgs, Chargino, Squarks and Neutralinos– NP contribution to rate or CP asymm. comparable or much larger than SM
• Provide ideal situation to develop and test theoretical tools for HF– Provide insight into non-trivial aspects of effective theory for heavy-light hadronic
transitions (factorization, ….shape function etc)
b s
*
bs : Signal and Backgrounds
signal
Proverbial Needle in a Hay Stack ! Hadronic BDecays
Initial StateRadiation
Continuume+ e- udsc jet
Bac
kgro
und
s
Inclusive b s Decay Rate
• Touted as “standard Candle of flavor physics” since theory robust
Not so rare, but important test of SM, Constrains parameters of beyond SM phenomena
B(B Xs) = (3.60 0.30) 104 [SM, (NLO )] Misiak and GambinoNucl. Phys B611,338(2001)
• Sensitive to Re(C7), New Physics can modify sign/phase of C7 leading to measurable rate enhancement, CPV and Isospin breaking effects
?• Experimental challenge is to sample as much of the photon spectrum as possible and understand background sources and rates
A bs Event In BaBar
Searches For Exclusive Final States in b d
central value 90% C.L. upper limit
2.6
5 observation expected for 1 ab-1/experiment
Rate of b d
• Decay CKM-suppressed (|Vtd /Vts| ) w.r.t. b s; sensitive to |Vtd|
• Inclusive b d measurements background challenged ! – b s 20 background ! Needs K+,KS and KL veto
• Exclusive processes are current exptal target: B ()– Theor. estimate imprecise B(B () ) (0.5-2.0)10-6
– Ratio R(/K*) reduces theory error, estimates |Vtd /Vts|
)1()0(
)0(
)(
)(2
*
2
*R
V
V
KBB
BBK
ts
td
Long distancecorrections ?
Form factor at q2=0SU(3) breaking corrections ?
The Decay Rate of b s l+l
• More complex than b s - W-box and Z-penguin amplitudes important - cc resonances in dilepton spectrum (removed by cuts on Mll)
• More observables - dilepton mass spectrum ( ) - forward–backward asymmetry (AFB)
• BR expectation in NNLO SM:
- B(B XS e+e) = (6.9 1.0) 106
- B(B XS +) = (4.2 0.7) 106
[Ali et al., Phys. Rev D66,034002(2002)]
q2 = M2ll
cd cs
ud u
td t
s b
b
s
c
tb
u
V VV
V
VV V
VV
Vcd
*Vcb
Vud
*Vub
*V Vtd tb
B Flavor Tagging By examining decay product in recoiling Btag
Category (%) w(%) Q(%)
Lepton 8.6 ±0.1 3.2 ±0.4 7.5 ±0.2
Kaon I 10.9 ±0.1 4.6 ±0.5 9.0 ±0.2
Kaon II 17.1 ±0.1 15.6 ±0.5 8.1 ±0.2
K- 13.7 ±0.1 23.7 ±0.6 3.8 ±0.2
Pion 14.5 ±0.1 33.9 ±0.6 1.7 ±0.1
Other 10.0 ±0.1 41.1 ±0.8 0.3 ±0.1
Total 74.9 ±0.2 30.5 ±0.4
(sin 2) 1Q
21 2Q w
Tagging performance
Effect of Measurement Imprecision on t Distribution
00tag BB 0 0
tagB B00tag BB 0 0
tagB B
Determine flavor mis- tag rates w and t resolution function R from large control samples of B0 D(*)//a1,J/K*
BB Mixing PDF
CP PDF
perfect flavor tagging & time
resolution
realistic mis-tagging & finite time
resolution
| t|/
CP, CPef ( t) 1 sin2 sin(1 2 ) m t
4
| t|/
mixing,ef ( t) 1 cos m t
4(1 2 )
~ 1 ps 170 m
~ 6 ps 1000 m2
t
mixt
sin2 From CPV in “Golden Mode”: B0 J/K0
S
S
S
*cb cs*cb c
*cs c
* *ψKB tb cb cd
ψK *B ψ
d*tb td td
* *tK tb cb t
*cs b cd dd ts cd
q A V V Vλ = =- =-
p A
V V
V V V
V V
V
V V V
V V V VV VS
S
ψK
ψK
Im(λ ) sin(2β)
λ 1
L SψK ψKλ λ
CP = -1 (+1)
for J/K0S(L)
2ie
0 t /S,L CPB J / K e 1 sin 2 sin( mt)
0 /,/ 1 sin 2 sin( )t
S L CPB J K e mt
0B
fiCPA e
CPf
0B
12
2 Mi
M
ie
fiCPA e
from B±D0 K±: D0 KS + - Dalitz Analysis
KS+ -
0SNote that D K decay dominated by quasi-2body amplitudes
0S
+ -B
Simultaneous fit to D K Dalitz distribution of
B info on and B r , data giv and ste rong phase s
Likelihood fits to the B->D(*)0 K(*) Dalitz Distributions
Combined
AnalysisStatistics Starved !
Kevin Pitts Heavy Flavors at the Tevatron slide 91
Measuring Bs Mixing Bs or Bs at the time of production?
Initial state flavor tagging Tagging “dilution”: D=1-2w, w=mistag rate Tagging power proportional to: D2
Bs or Bs at the time of decay? Final state flavor tagging Can tell from decay products (e.g. )
Yields Need lots of decays (because flavor tagging imperfect)
Proper decay time
Need decay length (Lxy) and time dilation factor ( =pT/mB)
Crucial for fast oscillations (i.e. Bs)
s sB D
T
xy
pBct
xy xy B
TL
T T
L L mct
m
p ppct
uncertainty
Typical tagging power:
D2 = (1%) at Tevatron
D2 = (30%) at BaBelle
Kevin Pitts Heavy Flavors at the Tevatron slide 92
Large semileptonic yields & good proper time resolution shown in new DØ Bs lifetime measurement BsDs X with Ds+ and KK+
5153265(stat.)450(syst.) signal events
(Bs) = 1.420 0.043(stat.) 0.057(syst.) ps World’s most precise measurement. Expect semileptonic mode to be 50/50 CP even/odd.
Bs Lifetime in Semileptonic Mode
Ds+ D++
Kevin Pitts Heavy Flavors at the Tevatron slide 93
,K+
Same side tagging Exploits fragmentation
Doesn’t require 2nd B hadron within acceptance
Correlations different for Bs, B+, B0
Cannot directly calibrate using B0 mixing
Flavor Tagging Opposite side tagging (lepton, jet charge)
Requires 2nd B hadron in detector acceptance Expect same performance same for B0, B+, Bs calibrate with B0 mixing
Opposite side
B
Lepton, jet charge
K
K
Lxy
same side K/ Signal B
Kevin Pitts Heavy Flavors at the Tevatron slide 94
Flavor Tagging Set a limit on ms: must know tagging dilution
Same as with CP violation measurments
Observe an oscillation: extract dilution from data For opposite side taggers, use B0 mixing for calibration.
Mixing in B0-D*+x
Mixing in fully reconstructed modes
Kevin Pitts Heavy Flavors at the Tevatron slide 95
DØ Bs Mixing in Semileptonics
Limit: ms > 5.0ps–1 @95% CLSensitivity: 4.6 ps–1
BsDs X (460 pb–1)
Ds Enhanced opposite
side tag 7037 events (376
tags) D2=(1.170.04)%
Raw asymmetry vs. visible proper decay length.
Kevin Pitts Heavy Flavors at the Tevatron slide 96
CDF Bs Mixing in Semileptonics BsDs + lepton (e/)
Ds , K*K, 4355 events Trigger: 4GeV e/ +
displaced track Opposite side flavor tags
- e,, jet charge D2=(1.430.09)%
Limit: ms > 7.7ps–1 @95% CLSensitivity: 7.3 ps–1
Rates and Asymmetries in B+ 0 , B0 0
0 0 0BF(B ) is large and does not satisfy
requirement for an effective Isospin analysis
Very weak constraint on [67o -131o]Not useful with current statistics
All Penguin Measurements Are Luminosity Limited
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40Ja
n-03
Jul-
03
Jan-
04
Jul-
04
Jan-
05
Jul-
05
Jan-
06
Jul-
06
Jan-
07
Jul-
07
Jan-
08
Jul-
08
Jan-
09
Jul-
09
Err
or
on
sin
e am
pli
tud
e
K*
5 discovery region if non-SM physics is a 30% effect
2004: 246 fb-1
2006: ~500 fb-1
Expect double BABAR luminosity by end 2006:
20062004
0Kσ(S )=0.30
f0KS
KS0
KS
KKKS ’KS
Belle may get there earlier !