Transcript Probing beyond the Standard Model with B Decays J. Chauveau LPNHE Univ. Paris 6-7 On behalf of the BABAR Collaboration ICHEP 2004, Aug.

Probing beyond the Standard
Model with B Decays
J. Chauveau
LPNHE Univ. Paris 6-7
On behalf of the BABAR Collaboration
ICHEP 2004,
Aug. 16th – 22nd, 2004
Beijing, China
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Outline
All results are preliminary unless otherwise noted
•
Interplay between theory and experiment
I.
sin 2b with gluonic penguins
II.
Polarization in B  Vector Vector decays
III. Puzzles in B  PP decays
IV. Rare radiative and (semi) leptonic decays
probing electroweak penguins
•
Summary and outlook
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•Where will New Physics peek
through the Standard Model
(CKM)?
Overview
Standard CKM fit
Updated for ICHEP04
Thanks CKM fitter group!
– Where SM itself depends on
virtual particles:
• B mixing,
• Penguin Decays (Rare processes).
– New physics brings new phases,
heavy particles we can see here.
•Look for
– Breakdown of Unitarity Triangle
• Doesn’t close ?
• different measurements of an
angle disagree?
– Rare processes which turn out not
to be rare.
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sin 2b in b  ccs tree decays
PRELIMINARY
See talk by M. Bruinsma in Session 8
ccbar KS, hfCP= -1
J/y KL, hfCP= +1
sin2β = 0.722  0.040 (stat)  0.023 (sys) prl
|l| = 0.950  0.031 (stat) 0.013 (sys)
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I. sin 2b in gluonic penguin mediated decays(1)
See talk by A. Hoecker (BABAR), and K.F. Chen (Belle) in session…
d
d
(B 0 (t )  fCP ) - (B 0 (t )  fCP )
AfCP (t ) 
(B 0 (t )  fCP ) + (B 0 (t )  fCP )
 -SfCP sin( md t ) + CfCP cos( md t )
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S fCP
2ImlfCP
1- l fCP
;
C fCP 
2
2
1+ lfCP
1+ l fCP
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sin 2b in gluonic penguin mediated decays (2)
Belle in 2003: 3.5 s from SM! Phys.Rev.Lett. 91 (2003) 261602
-hf.Sf
–0.96 ± 0.50 +0.09–0.11 0.47 ± 0.34 +0.08–0.06
K+K–KS 0.51 ± 0.26 ± 0.05
+0.18
η'KS
–0.00
0.43 ± 0.27 ± 0.05
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0.56 ± 0.25 ± 0.04
+0.17
+0.50 ±0.25 + 0.07-0.04
+0.55 ± 0.22 ± 0.12
–0.00
0.02 ± 0.34 ± 0.03
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+0.27 ± 0.14 ±0.03
PRELIMINARY
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ICHEP’04
2003
ΦK0
sin 2b in gluonic penguin mediated decays(3)
227 106 B pairs
PRELIMINARY
B   KS,L
hCP=+1
B0KS
SK 0  +0.29  0.31
B0KL
SK 0  -1.05  0.51
S
114 ± 12, 96 ± 18 events
S= + 0.50 ± 0.25 + 0.07-0.04
C= + 0.00 ± 0.23 ± 0.05
B  [K+K-non- KS
SKKKs  - 0.42  0.17
hCP=+1
L
452 ± 28 events
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sin2b in gluonic penguin mediated decays(3)
s-penguin average at 2.7s from sin2b[cc] (BABAR only)
PRELIMINARY
Also New:
B 0  f0 (980)K 0
The significant decrease in
the statistical errors allow to
perform interesting
comparisons.
Precise CP(t) measurement
0
0 0
B0  h K 0
in B   K
to watch.
100%
95%
90% pure-P
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II. Polarization in charmless B  VV decays(1)
See talk by A. Gritsan (BABAR) and J. Zhang (Belle) in session 11.
• Many spin-related observables of interest
(11 from 3 amplitudes of B and Bbar):
•Polarization fractions,
•Direct CP asymmetries
•Triple product asymmetries
• In the SM, expect longitudinal
polarization. Each spin flip (wrt e.g./ sL sRsL)
costs 1/mb in amplitude.
• B  K* puzzle (since 2002)
• Tree give fL~1, (=0.99 ± 0.05 r+r-).
• In K* (Penguin), fL ~0.5
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Polarization confirmed
B0   K*
PRELIMINARY
PRL
FSI
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Polarization in charmless B  VV decays(3)
B+ w r+
B0 K*0(1430)
PRELIMINARY
T
B- K*0 r-
P
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Polarization in charmless B  VV decays(4)
From A. Gritsan session 11
confirmed
less striking
Belle
Belle
hep-ex/3007014
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10.0 ± 1.6 ± 0.8
6.7 ± 2.0 ± 0.9
0.43 ± 0.09 ± 0.04
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Polarization in charmless B  VV decays(5)
In summary
•  K* The polarization puzzle fL ~0.5, remains with better statistics.
• Many observables available to attack the problem: ACP, AT.
• More penguin modes become measurable like r K*.
• The effect is less clear but the errors are still big.
• Tree dominated modes are fully polarized.
• An explanation is needed.
• New physics scenarios exist.
• Standard effects (strong interaction) to be understood.
• Many more measurements are in progress.
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b
u
III. The “K() puzzle”
u
s
Thanks
CKM
fitter
group!
q
q
q
q
5.8 ± 0.6 ± 0.4
1.2 ± 0.3 ± 0.1
12.0 ± 0.7 ± 0.6
25.9 ± 1.3 ± 1.1
11.4 ± 0.9 ± 0.6
PRELIMINARY
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•The experiments measure easily many hadronic branching ratios.
•The 2-body BF and Acp reach interesting precisions. (Lumi, PID)
• Phenomenologists try to understand the whole busy picture.
• Not so simple since ‘low energy’ QCD is at play in hadron dynamics
• Isospin : reliable guideline (see how  and rr can lead to gCKM)
• Models are built to match “unexpected features” high 00, low +• “Unexpected features “ also show up in K channels (less than 2 sigma effect).
• A scenario dealing with this “K  puzzle’ invokes electroweak-like penguin
isospin breaking amplitudes to tame the discrepancies.
• The scenario is predictive, so it’s fun:
K()
 C00= -0.40 ± 0.35 0.18, S00= -0.56 ±0.44
 C0KS= +0.05 ± 0.24 0.29, S0KS= -0.99 ±0.04 0.01
o Striking effect in rare K decays K  nn
 AFBCP=(0.03 ± 0.01) tan qY where qY~-1000 in K*mm, BIG.
 Enhancement of BF(b s,d nn) and BF(b mm) by factors 2 and 5.
 Could push up sin2b in  KS.
 A connection between hadronic and electroweak decays
Keep in mind, it’s 2sigma effect in strong interactions.
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J. Chauveau
- Probing beyond
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YoshikawaAug.
hep-ph0206147,
Gronau-Rosner
hep-ph/0307095,
Benecke-Neubert
0308039,
Buras, Fleischer, Recksiegel, Scwab hep-ph/0312259 &0402112
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0 0
The “K() puzzle”
PRELIMINARY
C= -0.12 ± 0.56 ±0.06
C= -0.09 ± 0.15 ± 0.04
S= -0.30 ± 0.17 ± 0.02
C=0.06 ± 0.18 ± 0.06
S= 0.35 ±0.30 0.33 ±0.04
0.01 ± 0.10 ± 0.02
-0.133 ± 0.030 ± 0.009
0.06 ± 0.06 ± 0.02
Direct CP violation!
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IV. Rare decays (radiative penguins)
See talks by J. Berryhill/H. Yang and H. Staengle/A. Ishikawa in session 8
•Electroweak FCNC in the SM
• The EWSB scale is probed in the loop diagrams.
A window on the high energy collider physics.
• CP violation phenomenology could be rich.
• Inclusive channels difficult to measure, well predicted by theory,
The opposite for the exclusive channels
• Highlights:
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b  r g shown in Moriond.
Time dependant CP violation in K*0(Ks 0) g
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Radiative penguin decays (2)
B  r(w)g
Bd  K* g CP(t)
M. Iwasaki at Moriond 2004
S = + 0.25 ± 0.63 ± 0.14
C = - 0.57 ± 0.32 ± 0.09
A première
PRELIMINARY
PRELIMINARY
BF/(10-6 ) = (1.8 ± 0.6 ± 0.1)
PRL
BF < 1.2 x10-6 90% CL
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0.9 - 1.6
PRL
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Rare decays (radiative penguins) (3)
b  s(d) g
 No surprise b  s g / (10-4)= 3.54 ± 0.30 (Exp.) vs 3.57 ± 0.30 (theo. NLO) !
 CP asymmetries not limited by systematics nor by theory.
 Time dependant ACP measured for the 1st time in radiative decays.
 b d g there?
b  s l +l  Lose one factor aem but access to virtuality. Measure Mll spectrum and AFB.
 A lot of new measurements to come.
b  s nnbar
 Expect BF/(10-6 )=
4
in SM, measure 90% c.l. UL
52 K nnbar
100  nnbar
0.3
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PRELIMINARY
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Rare leptonic decays(1)
See talk by G.P. Dubois-Felsman in session…
Clean in experiment and theory
Some extensions to the SM
increase BF(B0 l+l-) by
105
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SM
tn
9.3 ± 3.9 10-5
mn
4.2 ± 1.8 10 –7
e+e-
1.9 10-15
m+m-
8 10-11
e±m
0
nn,
nng
0
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Rare leptonic decays(2)
SM
NBB
(106)
Obs
Backg
tn
9.3 ± 3.9 10-5
124
10-72 8-55
3.3 10-4
mn
4.2 ± 1.8 10 –7
88
11
5 ±2
6.6 10-6
e+e-
1.9 10-15
123
0
0.71 ±0.31
6.1 10-8
m+m-
8 10-11
123
0
0.72 ±0.26
8.3 10-8
e±m
0
123
2
1.29 ±0.44
18 10-8
nn
nng
0
88
17
-1
19
28
22 10-5
4.7 10-5
(10-6)
U.L.(90%)
PRL
PRL
CLEO
hep-ex/0408011
PRELIMINARY
• No surprise yet
et < 11. 10-5
mt < 3.8 10-5
• Some limits are close to the SM.
• More data already on tape.
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Summary and outlook
•
•
•
•
B factory in full production.
Many channels challenge the UT.
No significant breaking of the SM.
Penguins (gluonic or electroweak or unknown) offer ways
to look for new physics in rare decays.
• The search reach an interesting level of precision.
 Intriguing BABAR-Belle differences.
 Therefore there are many effects (puzzles) to explore:
– sin2b in b s gluon.
– Polarization in B  Vector Vector.
– Pattern of the K (and ) Branching Fractions.
– Some rare decay searches reach the level of the SM.
A lot of action at the B factories for several years to come.
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Backup slides
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Luminosity
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sin 2b: BABAR/Belle Winter 2004
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sin2b in gluonic penguin mediated decays(3)
s-penguin average at 2.7s from sin2b[cc] (BABAR only)
no indication for direct CP violation
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Polarization in charmless B VV
decays(backup)
From A. Gritsan session 11
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Rare decays (radiative penguins) (backup)
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Radiative penguin decays (backup)
exclusive
inclusive
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Rare leptonic decays(backup)
tn
nn(g)
In MSSM with MFV
(Minimal Flavor Violation):
MH+ >138 GeV/c2
For tanbSUSY=60
PRELIMINARY
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New sans beta sans alpha
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Old
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New Avec beta et alpha
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