searching for new physics at a bfactory: why, where and howmaurizio pierini 1 slac experimental...
TRANSCRIPT
![Page 1: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/1.jpg)
1Maurizio Pierini
SLAC experimental Seminar 2/14/06
Searching for New Physics
at a Bfactory: Why, Where and How
Maurizio PieriniUniversity of Wisconsin,
Madison
![Page 2: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/2.jpg)
2Maurizio Pierini
SLAC experimental Seminar 2/14/06
Outline
Why: We have several reasons to consider
the Standard Model as an effective theory. But switching on new physics we generate the flavor problem
Where: all FCNC processes are loop induced in
the SM. New Physics can contribute as virtual states. We can learn a lot on where this is possible fromthe overconstraint of the CKM matrix. UTfit in and beyond the Standard Model
How: two possible scenarios from present bounds:
Minimal Flavor Violation: interplay between K and B physics at high luminosity facilitiesLarge Flavor Violation in 23 sector:(time dependent and time integrated) studies of bs decays
natural in many flavour models, given the strong
breaking of family SU(3)
![Page 3: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/3.jpg)
3Maurizio Pierini
SLAC experimental Seminar 2/14/06
Why New Physics at all?
Hierarchy problem: Renormalization of Higgs mass gives contributions ~Plank, but we want it to be few hundreds GeV. We don't want finetuning, so we need something (a symmetry?) that protects mH
Dark Matter: Standard Model does not provide a satisfactory candidate for dark matter ('s are not enough)
Grand Unification: coupling constants of weak, strong and electromagnetic interactions do not cross in a single point if we assume the Standard Model. They do in NPscenarios (SUSY)
![Page 4: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/4.jpg)
4Maurizio Pierini
SLAC experimental Seminar 2/14/06
Going Beyond: Flavor Problem
EW scale
NP contribution to EW precision, FCNC processes, CPV, etc.
The SM works beautifully up to a few hundredGeV's, but it must be an effective theory validup to a scale Mplanck
L(MW)=2H†H+(H†H)2+Lgauge+LYukawa+L5/+L6/2SM SM
The new contributions in general introduce new sources of CP violation and flavor mixing. The consistency of the Standard Model becomes a puzzle in this framework.We should see some discrepancy!!!!
NP contribution to g2, bs, etc
![Page 5: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/5.jpg)
5Maurizio Pierini
SLAC experimental Seminar 2/14/06
CP Violation in the SM
V CKM=Vud Vus VubVcd Vcs VcbVtd Vts Vtb ≃ 1−
2
2 A3 − i
− 1−2
2A2
A31− − i − A2 1
The mass eigenstates are not the eigenstates of weak
interaction. This feature of the SM Hamiltonian produces the
(unitary) mixing matrix VCKM
Since there are three families of quark, there is onephase that cannot be reabsorbed into the definition of the quark fields. This phase allows CP violation in the SM.
u
d
c t
s b
5
![Page 6: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/6.jpg)
6Maurizio Pierini
SLAC experimental Seminar 2/14/06
Testing SM: Unitarity Triangle
The unitarity of the matrix can be visualized as a triangle in a complex plane
normalized:
+i
several experimentalobservables depend
on ρ and η:
normalized:
1 +i
![Page 7: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/7.jpg)
7Maurizio Pierini
SLAC experimental Seminar 2/14/06
|Vub|
|Vcb|
Unitarity Triangle Analysis
Adding the “Classic” constraints...
K
∆md εK
∆md
∆ms
http://www.utfit.org/
M.Bona, M.Ciuchini, E.Franco, V.Lubicz,
G.Martinelli, F.Parodi, M.P.,
P.Roudeau, C.Schiavi,
L.Silvestrini, A.Stocchi
hepph/0501199
![Page 8: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/8.jpg)
8Maurizio Pierini
SLAC experimental Seminar 2/14/06
sin2β
...to the new bounds from B factories
γ α
cos2β
β from D0π0
2β+γ
sin2β
Unitarity Triangle Analysis
http://www.utfit.org/
![Page 9: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/9.jpg)
9Maurizio Pierini
SLAC experimental Seminar 2/14/06
Unitarity Triangle fit
Vub/Vcb + ∆md + ∆md/∆ms + εK + cos2β + β + + + 2β+γ + sin2β
η = 0.342 ± 0.022 [0.300, 0.385] @ 95% Prob.
ρ = 0.216 ± 0.036 [0.143, 0.288] @ 95% Prob.
sides+Kaon physics+
angles ρ
η
![Page 10: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/10.jpg)
10Maurizio Pierini
SLAC experimental Seminar 2/14/06
Tension in the fit? inclusive from HFAG Vub=(4.38±0.19±0.27)103
exclusive: BRs from HFAG;form factor from quenched LQCD
Vub=(3.80±0.27±0.47)103
incl.+excl.
Vub = (4.22 ± 0.20) 10-3
from all the other inputs:
Vub = (3.48 ± 0.20) 10-3
![Page 11: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/11.jpg)
11Maurizio Pierini
SLAC experimental Seminar 2/14/06
sin2 =0.7910.034from indirect determination
sin2=0.6870.0320.013From direct measurement
If we take it seriously,we want to go beyond the SM
The discrepancy remainseven including the model independentestimation of
theoretical erroron sin2
(Ciuchini,M.P,Silvestrini
hepph/0507290)
Tension in the fit
![Page 12: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/12.jpg)
12Maurizio Pierini
SLAC experimental Seminar 2/14/06
ρ = ± 0.18 ± 0.11η = ± 0.41 ± 0.05
Assuming no NP at tree level the effect of the D0D0
mixing to is negligible wrt the present error
semileptonic decays are clean
We have a NP free
determination ofρ andη
First Step: NPindependent fit
referencestarting point for NP model
building
M.Bona, M.Ciuchini, E.Franco, V.Lubicz, G.Martinelli, F.Parodi,
M.P., P.Roudeau, C.Schiavi, L.Silvestrini, A.Stocchi, V.Vagnoni hepph/0509219
![Page 13: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/13.jpg)
13Maurizio Pierini
SLAC experimental Seminar 2/14/06
J. M. Soares and L. Wolfenstein, Phys. Rev. D 47 (1993) 1021; N. G. Deshpande, B. Dutta and S. Oh, Phys. Rev. Lett. 77 (1996) 4499 [arXiv:hepph/9608231] J. P. Silva and L. Wolfenstein, Phys. Rev. D 55 (1997) 5331 [arXiv:hepph/9610208] A. G. Cohen et al., Phys. Rev. Lett. 78 (1997) 2300 [arXiv:hepph/9610252] Y. Grossman, Y. Nir and M. P. Worah, Phys. Rev. Lett. B 407 (1997) 307 [arXiv:hepph/9704287]
|εK|EXP = Cε⋅|εK|SM
∆mdEXP = Cd⋅∆md
SM
model independent assumptions
∆msEXP = Cs⋅∆ms
SM
ACP(J/ψK0) = sin (2β + 2φBd)
not yet available
5 unknowns
αEXP = αSM - φBd
6 available constraints
Second Step: Fit to NP
![Page 14: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/14.jpg)
14Maurizio Pierini
SLAC experimental Seminar 2/14/06
The UTfit beyond the SM
large NP witharbitrary phase(~4.3% Prob.)
SM or small NP witharbitrary phase
or large NP with SM phase (~95.7% Prob.)
“SM” η = 0.379 ± 0.039 ”NP” [0.398, 0.381] @ 95% Prob.
“SM” ρ = 0.246 ± 0.053 “NP” [0.230, 0.212] @ 95% Prob.
![Page 15: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/15.jpg)
15Maurizio Pierini
SLAC experimental Seminar 2/14/06
Bounds on NP parameters
CBd = 1.27 ± 0.44 φBd = 4.7 ± 2.3oPresent determination
Impact of B factories for 2008 on NP bound
now
2008
![Page 16: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/16.jpg)
16Maurizio Pierini
SLAC experimental Seminar 2/14/06
New sources of CPV in b→s transitions are – much less (un)constrained by the UT fit– natural in many flavour models, given the strong breaking of family SU(3)
Pomarol, Tommasini; Barbieri, Dvali, Hall; Barbieri, Hall; Barbieri, Hall, Romanino; Berezhiani, Rossi; Masiero et al; …
Where do we go from here?
Completing the physics program for'08 BaBar can testboth the scenarios
MFVmodels
LargeFV
models
New sources of CPV in s→d and/or b→d transitions are
• strongly constrained by the UT fit • “unnecessary”, given the great success and consistency of the fit
![Page 17: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/17.jpg)
17Maurizio Pierini
SLAC experimental Seminar 2/14/06
First Case: New Physicsis Minimal
Flavor Violating in thebd sector. No
additional CP violation
![Page 18: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/18.jpg)
18Maurizio Pierini
SLAC experimental Seminar 2/14/06
We can determine and in a universal way for (MFV) NP and SM. εK and ∆md are not used.
ρ = 0.258 ± 0.066 UUTfit
Buras et al. hepph/0007085
η = 0.319 ± 0.039 UUTfit
The Starting Point
18
![Page 19: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/19.jpg)
19Maurizio Pierini
SLAC experimental Seminar 2/14/06
From UT to Rare decays
Dimension 4 operators: FCNC effective Z vertex C=CSM+∆C (constrained by BR(B → Xsl
+l)
and BR(K++))
Dimension 5 operators: (chromo)magnetic penguin
C7eff=(C7
eff)SM+∆C7eff (constrained by BR(B→Xsγ))
Dimension 6 operators: penguins, boxes subleading NP contributions to rare decays
Rare decaysSM functions + ∆C, ∆C7eff
C.Bobeth, M.Bona, A.J.Buras, T.Ewerth, M.P., L.Silvestrini, A.Weiler, hepph/0505110
![Page 20: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/20.jpg)
20Maurizio Pierini
SLAC experimental Seminar 2/14/06
SM like solution
Oppositesign of C
Oppositesign of C7
eff
Constraint on NP contributions
20
![Page 21: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/21.jpg)
21Maurizio Pierini
SLAC experimental Seminar 2/14/06
In MFV models (at low/moderate tanβ) rare decays can be only slightly enhanced w.r.t the SM. Strong suppressions still possible at present.
The Lesson from MFV
If this is the case, we need very high statistics
![Page 22: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/22.jpg)
22Maurizio Pierini
SLAC experimental Seminar 2/14/06
Second Case: New Physicsbrings additional CP violation in the
bs sector We will restrict to SUSY in what follows
![Page 23: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/23.jpg)
23Maurizio Pierini
SLAC experimental Seminar 2/14/06
In general, SUSY generates additional processesthat can contribute to bs transitions
In this case thetransition is generatedby a strong interactionWe gain a factor gs/gW
that can compensate the suppression of the propagator
~1/mq~2
SUSY & bs decays
![Page 24: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/24.jpg)
24Maurizio Pierini
SLAC experimental Seminar 2/14/06
m11
m12
m13
m21
m22
m23
m31
m32
m33 md
00
0ms
0
00
m b
m112
m122
m132
m 212
m222
m 232
m312
m322
m332
ABm d
2
00
0ms
2
0
00
m b2
AB
m q2 0
12AB
13AB
12∗BA
023
AB
13∗BA
23∗BA
0 quark rotation( generating CKM matrix)
Effective interaction(mass insertion)
between second and third family
chirality of incoming and outgoing squarks (LL,LR,RL,RR)
average squark mass
Mass Insertions
24
![Page 25: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/25.jpg)
25Maurizio Pierini
SLAC experimental Seminar 2/14/06
gluinos contribute to rare decays only through(chromo)magnetic penguins; (electro) penguin operators are suppressed
Strong bounds from the combination of bsll and bsγWe can impose the experimental results to bound thesize of the δ's
Bertolini et al., NPB353; Gabbiani et al., NPB477; Buras, Romanino, Silvestrini, NPB520
Ciuchini et al, PRD67; Hiller, PRD69; Gambino,Haisch,Misiak, PRL94
Effect of SM operators
The new amplitudes have arbitrary phases.We are going to look for them in CPViolating processes
![Page 26: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/26.jpg)
26Maurizio Pierini
SLAC experimental Seminar 2/14/06
Re(d23)LLvsIm(d23)LL
No bsllWith bsll
Re(d23)RRvsIm(d23)RR
Re(d23)LRvsIm(d23)LRRe(d23)RLvsIm(d23)RL
Constraints on δ's
26
tanβ = 10 mg = mq = µ =
350 GeV, ~ ~
![Page 27: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/27.jpg)
27Maurizio Pierini
SLAC experimental Seminar 2/14/06
The Effect of δRL on S
SKvs Im(d23)RLSkvs Im(d23)RL
Skvs Im(d23)RLSk'vs Im(d23)RL
Using BR's and direct CP asymmetry(as for the SM fit)Switching on onlyone of the four
chiralities
27
![Page 28: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/28.jpg)
28Maurizio Pierini
SLAC experimental Seminar 2/14/06
Accessing the δ's with Exp.
mixing
decay
decay
B0
B0
fCP
f CP=
qp⋅
A f CP
A f CP
=∣ f CP∣⋅e− 2iCP
mixing
decay
AfCP=
Bphys0 tfCP− Bphys
0 tfCP
Bphys0 tfCPBphys
0 tfCP=CfCP
cosmdtSfCPsinmdt
C f CP=
1− ∣ f CP∣2
1∣ f CP∣2
S f CP=−
2CP ℑ f CP
1∣ f CP∣2
With only one CKM term in the decay (A = A)
C=0 ; S=sin2
Standard Model predictions
![Page 29: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/29.jpg)
29Maurizio Pierini
SLAC experimental Seminar 2/14/06
sidebands
signal region
MeV
GeV/c2
The beamenergy substituted mass
The energy difference(halfCM energy)
BoostLab frame CM frame
two largely independent analysis variables
dominated by beam energy spread
dominated by energy resolution
B Candidate Reconstruction
mES=Ebeam∗2 − pB
∗2
E=E beam∗ − s /2
Ebeam∗ = s /2
P=E ,p P∗=E∗ ,p∗
mES≈2.6 MeV /c2
E≈10÷40 MeV /c2
![Page 30: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/30.jpg)
30Maurizio Pierini
SLAC experimental Seminar 2/14/06
e+e
(βγ)Υ(4s) = 0.56
B mesons pair oscillating in a coherent state
l +
K+
π+
φΚ+
Κ−
K0S
π−
π+
z
t≈z
c∣ z∣~200m
Breco
BtagY(4S)
Vertex Reconstruction
![Page 31: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/31.jpg)
31Maurizio Pierini
SLAC experimental Seminar 2/14/06
log scaleMixedevents
∆t p.d.f.(from data)
∆t = trecttag
log scaleUnmixedevents
We can fit directly on data the parameterization of the Vertex resolution function, using a sample of fully
reconstructed B events
![Page 32: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/32.jpg)
32Maurizio Pierini
SLAC experimental Seminar 2/14/06
Separately determine D for each tag category.
τΒ=1.6 ps
Overall taggingperformance
Mistag (ω) measurement (from data)
Amix=NoMix t − Mix t NoMix t Mix t
f UnmizedMixed
={e− ∣t∣/B
4B
[1 1− 2cos md t ]} R t
∆md = 0.501ps1 (fixed to PDG'04)
D=(12ω)<1 due to mistagsT=2π/∆md
ε=(74.90.2)%
Q = ε(12ω)2
= (300.4)%)
![Page 33: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/33.jpg)
33Maurizio Pierini
SLAC experimental Seminar 2/14/06
The BC Vertexing (I)
y
xπ0
π+ π
Ks
~4 µm
γ
~200 µm
γ
~30 µm
Several of these channels do not have charged tracks from the B vertex. But we can extrapolate back the KS: Using the constraint of the beam
spot on the transverse plane Requiring the KS to decay in the
inner part of the SVT
Beam spot constraint on transverse plane
e+e
γ
Ks
π+
π yz
Btag
Breco
γ
Beam
![Page 34: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/34.jpg)
34Maurizio Pierini
SLAC experimental Seminar 2/14/06
KS xy decay length
# insufficienthits in the SVT
signal MC DistributionBC vertexing resolutionposition of SVT layers
∆t resolution
We split our sample in 4 KS classes
Class I: 1 z & 1 φ hit in SVT layers 13 for both π± Class II: not Class I events with 1 z & 1φ SVT hit for both π± Class III: 1 SVT hit on both π±
Class IV: no SVT hit
Class I&II determine S
All classes determine C
The BC Vertexing (II)
34
![Page 35: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/35.jpg)
35Maurizio Pierini
SLAC experimental Seminar 2/14/06
z resolution vs. Ks xy decay
length
∆t resolution vs. cos θ
Validation on J/ψ Ks(standard vtx. vs BC vtx).
Comparison data vs. MC to parameterize ∆t: ~1% difference in the outliers fraction (quoted systematic effect for BC vtx)
The BC Vertexing (III)
![Page 36: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/36.jpg)
36Maurizio Pierini
SLAC experimental Seminar 2/14/06
Signal
Bkg
qq Background rejection Main source of background from e+e →qq. We can use the different topology to reject them
Several possible topology variables (|cos(θSPH)| , L2/L0, Fisher F(p,θ), NN)
Cut in the selection (8090% eff. on signal) Residual discriminating power
in the likelihood fit
|cos(θSPH)|
F(p,θ)
L2/L0
Signal
Bkg
B produced ~ at rest isotropic topology
qq events jetlike
36
![Page 37: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/37.jpg)
37Maurizio Pierini
SLAC experimental Seminar 2/14/06
K*00 K00
|cos(HEL)| for
mφ bkg
Final states with same multiplicity but different resonances ( vs. f0)
We use helicity and invariant mass
Final states with higher multiplicity Strongly suppressed by lower cut on E
m(KK)
∆E
BB Background rejection
Irreducible and combinatoric background is taken into account in the likelihood
![Page 38: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/38.jpg)
38Maurizio Pierini
SLAC experimental Seminar 2/14/06
Structure of the Likelihood
Shape ofKinematicVariables
=e− N SNqq N BB∏j
N TOT
NS⋅PSj mES ⋅ PS
j E ⋅ PSj f L2, L0 ,... ⋅ PS
j m , H ⋅ PSj t
N qq⋅Pqqj mES ⋅Pqq
j E ⋅ Pqqj f L2, L0 , ...⋅ Pqq
j m , H ⋅ Pqqj t
N BB⋅PBBj mES ⋅PBB
j E ⋅ PBBj f L2, L0 , ...⋅ PBB
j m , H ⋅ P BBj t
Shape ofTopologicalVariables
(Fisher, NN, ...)
Additional Variables(mass, helicity, ...)for BB bkg rejection
t information(to measures S and C)
L
Signal
qq Background
BB Background
Poisson factor for Extended
Maximum Likelihood Fits
![Page 39: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/39.jpg)
39Maurizio Pierini
SLAC experimental Seminar 2/14/06
Fit of B0φK0 events
S=0.50±0.25− 0.040.07
C=0.00±0.23±0.05
KS
11412 events
KL
9818 events
KL
KSACP
ACP
![Page 40: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/40.jpg)
40Maurizio Pierini
SLAC experimental Seminar 2/14/06
Fit of B0KSπ0 events
bkgsig t
S=0.35− 0.330.30 ±0.04
C=0.06±0.18±0.03
30023 events
Phys.Rev. D71 (2005) 111102
ACP
![Page 41: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/41.jpg)
41Maurizio Pierini
SLAC experimental Seminar 2/14/06
Fit of B0K0SK
0SK
0S events
all KS→π+π−
88±10 events
~100% w/ good vertex
*sPlot
all events
one KS→π0π0
45±7 events
one KS with both pions ≥4 SVT hits~97% w/ good vertex
S=0.63− 0.320.28 ±0.04
C=− 0.10±0.25±0.05
Phys.Rev.Lett. 95 (2005)011801
hepex/0507052
hepex/0507052
t
ACP
![Page 42: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/42.jpg)
42Maurizio Pierini
SLAC experimental Seminar 2/14/06
Fit of B0K*0γ events
tPhys.Rev. D72 (2005) 051103
S=− 0.21±0.40±0.05C=− 0.40±0.23±0.03
30023events
SK S
0 ≈− 2ms
mb
sin 2 ≈0
CK
S0 ≈0
in SM we expect
because ofhelicity suppression42
ACP
![Page 43: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/43.jpg)
43Maurizio Pierini
SLAC experimental Seminar 2/14/06
Where We Are Now...
![Page 44: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/44.jpg)
44Maurizio Pierini
SLAC experimental Seminar 2/14/06
And What It Means...
adding S measurements
extrapolationto 2008
Re(d23)RLvsIm(d23)RL
No bs time dep. With bs time dep.
BaBar abd Belle will reduce the bulk of parameter space
![Page 45: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/45.jpg)
45Maurizio Pierini
SLAC experimental Seminar 2/14/06
we can do betterwith K* decays
Other smoking guns?
Puzzling situationin K BR's In SM we expect R~Rc~Rn~1
Still 1.5 includingradiative corrections
E.Baracchini, M.Ciuchini, G.Isidori, M.P, L.Silvestrini
in preparation
CP violation in K+ has also implications on ACP of other decays, depending on the assumed hadronic model.
In principle, we should get a bound on to compare to other determinationsMain Limitation: the presence of penguins imply hadronic uncertanties.
![Page 46: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/46.jpg)
46Maurizio Pierini
SLAC experimental Seminar 2/14/06
Using Dalitz: a new CKM bound
A(B0 → Κ∗+ π−) = Vts Vtb* × P1 - Vus Vub
* × {E1-P1GIM}
A(B+ → Κ∗0 π+) = - Vts Vtb* × P
1 + Vus Vub
* × {A1-P
1GIM}
A(B0 → Κ∗0 π0) = - Vts Vtb* × P1 - Vus Vub
* × {E2+P1GIM}
Vus Vub*~ λ4Charming Penguin ~ λ2
Formally equivalent to BK decays The hadronic parameters are
numerically different than for K But we can access Abs and Arg of
the amplitudes through the interference in Dalitz Plots
K*+(0) K*0()0
B0()
K+(0)0
A(B+ → Κ∗+ π0) = Vts Vtb* × P
1 - Vus Vub
* × {E1+E
2+A
1-P
1GIM}
2⋅2⋅
46
M.Ciuchini, M.P. & L.Silvestrini, hepph/0601233
![Page 47: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/47.jpg)
47Maurizio Pierini
SLAC experimental Seminar 2/14/06
It is possible to experimentally access I=3/2 amplitude
A0=AK∗− 2 AK 00 =− V ub∗ V usE1E2
A=AK∗0 2 AK 0=− V ub∗ V us E1E2
from K+0 Dalitz plot
from K0+0 Dalitz plot
Assuming (for the moment) no EW Penguins, the ratio of these quantities and their CP conjugatedmeasures
R0=A0
A0 =V ub V us
∗
V ub∗ V us
= e− 2i =A−
A =R∓Same argumentapplies to higherK* resonances
Cancellation of Penguins
![Page 48: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/48.jpg)
48Maurizio Pierini
SLAC experimental Seminar 2/14/06
Inclusion of EW Penguins EW penguins are suppressed ~em respect to strong penguins but they are enhanced by 2 respect to I=3/2 amplitude They provide an O(1) correction. We use
to write
R becomes
where
Q9=32Q1
suu− Q1scc3Q1
scc−12
Q3s ; Q10=
32Q2
suu− Q2scc3Q2
scc−12
Q4s
H eff ∝V ub∗ V usC1−
32
V tb∗ V ts C9 Q1
suu− Q1scc
V ub∗ V usC2−
32
V tb∗ V ts C10Q2
suu− Q2scc − V tb
∗ V ts H peng I =1/2
R0 = R∓ = e− 2i Arg 1EW
EW=−32
C9C10
C1C2
V tb∗ V ts
V ub∗ V us
=32
C9C10
C1C211− 2/2 2
2 i
Q7 and Q8 neglected
|C7,8|<<|C9,10|
48
![Page 49: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/49.jpg)
49Maurizio Pierini
SLAC experimental Seminar 2/14/06
Bound on CKM from Arg(R0)
A measurement of B0K+0 Dalitz exists, which determines both K* and K*(1430) and provides Arg(R0)with an error of 18o. We do not have K0 Dalitz plot yet, so the relative phase of B and B cannot be fixedWe can assume a perfect agreement to SM and ...
Possible improvements fitting directly for R
(cancellation of systematics) using all BaBar & Belle current data adding charged modes
The precision is already comparable to from DK
crossing point
0=−32
C9C10
C1C2C9C10
1− 2 /22
2...20o of error
...40o
of error
BaBar, hepex/0408073
49
Same technique gives with the Bs(M.Ciuchini, M.P.,
L.Silvestrini,in preparation)
![Page 50: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/50.jpg)
50Maurizio Pierini
SLAC experimental Seminar 2/14/06
What Next: A Linear SuperB?Using the present technology and the R&D for the ILC, we recently proposed a new kind of machine to build
A small version of the ILC that runs at the Y(4S), with a reduced boost (~0.20.3) and a better vertex resolution (thanks to smaller beamspot and limited multiple scattering). Possible luminosity as large as ~35 1036 (now it is ~1034) Worse knowledge of the CM energy
50
J.Albert et al., physics/0512235
![Page 51: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/51.jpg)
51Maurizio Pierini
SLAC experimental Seminar 2/14/06
even in this situation same∆z resoultion as now
Furthermore
Main Differences w.r.t. BaBar
More Energy spreadless B Less
Boost
BaBar
SuperB
51
![Page 52: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/52.jpg)
52Maurizio Pierini
SLAC experimental Seminar 2/14/06 52
Benefits of a better vtx detector
Still Under Investigation
![Page 53: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/53.jpg)
53Maurizio Pierini
SLAC experimental Seminar 2/14/06
How Things Will Look Like
S(K) vs Im(23)RL
S('K) vs Im(23)RL
assuming 50ab1
![Page 54: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/54.jpg)
54Maurizio Pierini
SLAC experimental Seminar 2/14/06
Conclusions The combination of current constraints on and suggests Consistency of the SM Stringent constraint on New Physics in bd (MFV) No implication on bs (Large FV still possible)In MFV: NP can suppress, but not enhance, the ratesIn Large FV: We expect effects in bs decays Several channels studied, thanks to new techniques Current data show some pattern (S<sin2) but errors are still largeAdditional information can come from rates and amplitudes on Dalitz K puzzle New Bound on CKM from K*We need more data and interplay with LHC and ILCa new linear super B factory can say the last word on flavor physics
![Page 55: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/55.jpg)
55Maurizio Pierini
SLAC experimental Seminar 2/14/06
Backup Slides
![Page 56: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/56.jpg)
56Maurizio Pierini
SLAC experimental Seminar 2/14/06
DIRC (PID)144 quartz bars
11000 PMs
1.5T solenoid
EMC6580 CsI(Tl) crystals
Drift Chamber40 layers
Instrumented Flux ReturnIron / Resistive Plate Chambers or Limited Streamer Tubes (muon /
neutral hadrons)
Silicon Vertex Tracker5 layers, double sided strips
e+ (3.1GeV)
e− (9GeV)
Asymmetric geometry (in order to optimize performances for the
boost of the restframe respect to LAB)
![Page 57: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/57.jpg)
57Maurizio Pierini
SLAC experimental Seminar 2/14/06
The OPE and decay amplitudesSince mb~4GeV and mW~80GeV, weak interaction canbe replaced by an effective local theory, contracting the W propagator to a point (similarthing to be done with t quark)
1p2mW
2 O( )1p2
mW2
This operation breaks the ultraviolet behaviour of the theory.
To remove the after integrating out the heavy degrees of freedomwe need to renormalize the theory, which introduces new operators and effective couplings, as a function of an unphysical regularization scale (µ).
∫ d 4 p
p6≈ ∫ dp
p3 0 ∫ d 4 p
p4≈ ∫ dp
p∞
2 fermions 2 bosonsin the loop 2 fermions
1 boson inthe loop
57
![Page 58: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/58.jpg)
58Maurizio Pierini
SLAC experimental Seminar 2/14/06
The effective Hamiltonian
After the renormalization of the effective theory we get
Penguinoperators
EW Penguinoperators
(cromo)magnetic operators
Tree level operators
![Page 59: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/59.jpg)
59Maurizio Pierini
SLAC experimental Seminar 2/14/06
Contractions of the Heff
Contracting (by Wick theorem) the effective Hamiltonian on certain initial and final states
AB0 K− =K − ∣H eff∣B0= ∑i=1,10
Ci K− ∣Qi∣B0
B π
K
π
K
B
All the perturbative physics (scale > µ) in the Wilson coeff.Ci(µ). All the nonperturbative physics (scale < µ) in thematrix elements. The unphysical dependence on µ has to cancelout. Every operator can produce several diagram topologies whencontracted on the initial and final states. For example, the tree level operators can be contracted into tree levelcontractions <Q>DE(µ) and <Q>CE(µ)
DE CE
59
![Page 60: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/60.jpg)
60Maurizio Pierini
SLAC experimental Seminar 2/14/06
The RGI combinations One can rearrange the contractions of various operators into Renormalization Group Invariant combinations, that represent the physical quantities defining the decay amplitude (Buras &Silvestrini, hepph/9812392). For example the tree level contributions T and C correspond to the RGI's E1 and E2
E1=C1<Q1>DE+C2<Q2>CE E2=C1<Q1>CE+C2<Q2>DE
Penguins are more complicated Every RGI correponds to a contraction of the JµJµ interaction term of the Standard Model (i.e. RGIs are the physical quantities)
![Page 61: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/61.jpg)
61Maurizio Pierini
SLAC experimental Seminar 2/14/06
B
B πc (cu)
K,π
K, π
π
P1(GIM)
A2
Disconnected Annihilation
Charming and GIM penguins(cu)
K, π
π
B Connected Annihilation
![Page 62: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/62.jpg)
62Maurizio Pierini
SLAC experimental Seminar 2/14/06
Preliminary
A comment about radiative effects
What we calculate is the weak decay amplitudeThe experimental measurement includes radiative effect
|A(Bf)|2 = |AW(Bf)|2 G()experimentalobservable
the calculated decay amplitude the QED
correction(dependent on the energy cutoff)
Baracchini & Isidorihepph/0508071
We have to correct each result according to the energy cutoff
![Page 63: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/63.jpg)
63Maurizio Pierini
SLAC experimental Seminar 2/14/06
Predictions for Rare K and B Decays
63
![Page 64: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/64.jpg)
64Maurizio Pierini
SLAC experimental Seminar 2/14/06
In SM the photon is almost fully polarized: AR ~ ms/mb AL
New Physics effects can enhance AR
CP Asimmetry from a final state with mixed CP content. In SM C~0, S~ 2ms/mb •sin(2β)
bR sLbL
L
~mb
sLbL sR
R
~ms
helicity suppression
B0K*0γ In The SM
![Page 65: Searching for New Physics at a Bfactory: Why, Where and HowMaurizio Pierini 1 SLAC experimental Seminar 2/14/06 Searching for New Physics at a Bfactory: Why, Where and How Maurizio](https://reader034.vdocuments.site/reader034/viewer/2022042112/5e8e58f2f8153b147f26adcd/html5/thumbnails/65.jpg)
65Maurizio Pierini
SLAC experimental Seminar 2/14/06
Integrating
Taking the maximum
Both the methods have assumptions. At least in one case they are clear
(flat prior on P). And this is not a 2D Gaussian....