Probing beyond the Standard Model with B Decays

Transcription

1 Probing beyond the Standard Model with B Decays J. Chauveau LPNHE Univ. Paris 6-7 On behalf of the BABAR Collaboration ICHEP 2004, Aug. 16 th 22 nd, 2004 Beijing, China ICHEP'04 Aug J. Chauveau - Probing beyond... 1

2 Outline Interplay between theory and experiment I. sin 2β with gluonic penguins II. All results are preliminary unless otherwise noted III. IV. Polarization in B Vector Vector decays Puzzles in B PP decays Rare radiative and (semi) leptonic decays probing electroweak penguins Summary and outlook ICHEP'04 Aug J. Chauveau - Probing beyond... 2

3 Where will New Physics peek through the Standard Model (CKM)? 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. Overview Standard CKM fit Updated for ICHEP04 Thanks CKM fitter group! ICHEP'04 Aug J. Chauveau - Probing beyond... 3

4 sin 2β in b ccs tree decays See talk by M. Bruinsma in Session 8 ccbar K S, η fcp = 1 J/ψ K L, η fcp = +1 PRELIMINARY sin2 = ± (stat) ± (sys) λ = ± (stat) ±0.013 (sys) ICHEP'04 Aug J. Chauveau - Probing beyond... 4 prl

5 I. sin 2β in gluonic penguin mediated decays(1) See talk by A. Hoecker (BABAR), and K.F. Chen (Belle) in session d d A f CP ( t) Γ Γ = Γ + Γ 0 0 ( B ( t) fcp ) ( B ( t) fcp ) 0 0 ( B ( t) fcp ) ( B ( t) fc P ) = S sin( m t) + C cos( m t) f CP d f CP d S f CP 2Im = 1+ λf [ λfcp] ; CP 2 Cf CP 1 λf = 1+ λf CP CP 2 2 ICHEP'04 Aug J. Chauveau - Probing beyond... 5

6 sin 2β in gluonic penguin mediated decays (2) Belle in 2003: 3.5 σ from SM! Phys.Rev.Lett. 91 (2003) η f.s f K ± ± ± K + K K S 0.51 ± 0.26 ± ± 0.25 ± ± 0.22 ± 'K S 0.43 ± 0.27 ± ± 0.34 ± ± 0.14 ±0.03 PRELIMINARY ICHEP'04 Aug J. Chauveau - Probing beyond... 6 ICHEP 04

7 sin 2β in gluonic penguin mediated decays(3) B pairs η CP =+1 B 0 φk S S φ 0 = ± 0.31 K S B φ K S,L 114 ± 12, 96 ± 18 events PRELIMINARY S= ± C= ± 0.23 ± 0.05 B [Κ + Κ ] non-φ K S S KKKs = 0.42 ± 0.17 η CP =+1 B 0 φk S = ± L φ KL ± 28 events ICHEP'04 Aug J. Chauveau - Probing beyond... 7

8 sin2β in gluonic penguin mediated decays(3) Also New: B f (980) K The significant decrease in the statistical errors allow to perform interesting comparisons. Precise CP(t) measurement in B π K B η K to watch. s-penguin average at 2.7σ from sin2β[cc] (BABAR only) PRELIMINARY 100% 95% 90% pure-p ICHEP'04 Aug J. Chauveau - Probing beyond... 8

9 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./ s L s R s L ) costs 1/m b in amplitude. B φk* puzzle (since 2002) Tree give f L ~1, (=0.99 ± 0.05 ρ + ρ ). In φk* (Penguin), f L ~0.5 ICHEP'04 Aug J. Chauveau - Probing beyond... 9

10 Polarization confirmed No sign of CP violation B0 φ K* PRL PRELIMINARY FSI ICHEP'04 Aug J. Chauveau - Probing beyond... 10

11 Polarization in charmless B VV decays(3) B+ ω ρ+ B0 φ K*0(1430) T PRELIMINARY B- K*0 ρ P ICHEP'04 Aug J. Chauveau - Probing beyond... 11

12 Polarization in charmless B VV decays(4) From A. Gritsan session 11 confirmed less striking Belle Belle hep-ex/ ± 1.6 ± ± 2.0 ± ± 0.09 ± ICHEP'04 Aug J. Chauveau - Probing beyond... 12

13 Polarization in charmless B VV decays(5) In summary φ K* The polarization puzzle f L ~0.5, remains with better statistics. Many observables available to attack the problem: A CP, A T. More penguin modes become measurable like ρ 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. ICHEP'04 Aug J. Chauveau - Probing beyond... 13

14 b u s u III. The K(π)π puzzle Thanks CKM fitter group! q q Z,γ q q 5.8 ± 0.6 ± ± 0.3 ± ± 0.7 ± ± 1.3 ± ± 0.9 ± 0.6 PRELIMINARY ICHEP'04 Aug J. Chauveau - Probing beyond... 14

15 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 ππ and ρρ can lead to γ CKM ) Models are built to match unexpected features high π 0 π 0, low π+π Unexpected features also show up in Kπ channels (less than 2 sigma effect). A scenario dealing with this K π puzzle invokes electroweak-like penguin isospin breaking amplitudes to tame the discrepancies. The scenario is predictive, so it s fun: C π0π0 = 0.40 ± , S π0π0 = 0.56 ±0.44 C π0κs = ± , S π0κs = 0.99 ± o Striking effect in rare K decays K πνν A CP FB =(0.03 ± 0.01) tan θ Y where θ Y ~ in K*µµ, BIG. Enhancement of BF(b s,d νν) and BF(b µµ) by factors 2 and 5. Could push up sin2β in φ K S. A connection between hadronic and electroweak decays Keep in mind, it s 2sigma effect in strong interactions. K(π)π ICHEP'04 Yoshikawa Aug. hep-ph , Gronau-Rosner J. Chauveau hep-ph/ , - Probing beyond Benecke-Neubert , 15 Buras, Fleischer, Recksiegel, Scwab hep-ph/ &

16 π 0 π 0 The K(π)π 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 ± ± ± 0.10 ± ± ± ± 0.06 ± 0.02 Direct CP violation! ICHEP'04 Aug J. Chauveau - Probing beyond... 16

17 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: b ρ γ shown in Moriond. Time dependant CP violation in K* 0 (Ks π 0 ) γ ICHEP'04 Aug J. Chauveau - Probing beyond... 17

18 Radiative penguin decays (2) Bd K* γ CP(t) B ρ(ω)γ M. Iwasaki at Moriond 2004 BF/(10-6 ) = (1.8 ± 0.6 ± 0.1) PRELIMINARY S = ± 0.63 ± 0.14 C = 0.57 ± 0.32 ± 0.09 A PRL PRELIMINARY Theory: ICHEP'04 Aug J. Chauveau - Probing beyond PRL

19 Rare decays (radiative penguins) (3) b s(d) γ No surprise b s γ / (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 A CP measured for the 1st time in radiative decays. b d γ there? b s l + l Lose one factor α em but access to virtuality. Measure M ll spectrum and A FB. A lot of new measurements to come. b s νν νν bar PRELIMINARY Expect BF/(10-6 )= 4 in SM, measure 90% c.l. UL 52 K νν νν bar π νν νν bar ICHEP'04 Aug J. Chauveau - Probing beyond... 19

20 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 10 5 τν µν e+e- µ+µ SM 9.3 ± ± νν, ννγ ICHEP'04 Aug J. Chauveau - Probing beyond e±µ 0 0

21 Rare leptonic decays(2) SM N BB (10 6 ) Obs Backg U.L.(90%) (10-6 ) τν µν 9.3 ± ± ± PRL e+e ± µ+µ ± e±µ νν ννγ 1 No surprise yet Some limits are close to the SM ± PRELIMINARY PRL CLEO hep-ex/ eτ < µτ < More data already on tape. ICHEP'04 Aug J. Chauveau - Probing beyond... 21

22 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: sin2β in b s gluon. Polarization in B Vector Vector. Pattern of the Kπ (and ππ) 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. ICHEP'04 Aug J. Chauveau - Probing beyond... 22

23 Backup slides ICHEP'04 Aug J. Chauveau - Probing beyond... 23

24 Luminosity ICHEP'04 Aug J. Chauveau - Probing beyond... 24

25 sin 2β: BABAR/Belle Winter 2004 ICHEP'04 Aug J. Chauveau - Probing beyond... 25

26 sin2β in gluonic penguin mediated decays(3) s-penguin average at 2.7σ from sin2β[cc] (BABAR only) no indication for direct CP violation ICHEP'04 Aug J. Chauveau - Probing beyond... 26

27 Polarization in charmless B decays(backup) VV From A. Gritsan session 11 ICHEP'04 Aug J. Chauveau - Probing beyond... 27

28 Rare decays (radiative penguins) (backup) ICHEP'04 Aug J. Chauveau - Probing beyond... 28

29 Radiative penguin decays (backup) exclusive inclusive ICHEP'04 Aug J. Chauveau - Probing beyond... 29

30 Rare leptonic decays(backup) τν νν(γ) In MSSM with MFV (Minimal Flavor Violation): M H+ >138 GeV/c 2 For tanβ SUSY =60 PRELIMINARY PRELIMINARY ICHEP'04 Aug J. Chauveau - Probing beyond... 30

31 New sans beta sans alpha ICHEP'04 Aug J. Chauveau - Probing beyond... 31

32 Old ICHEP'04 Aug J. Chauveau - Probing beyond... 32

33 New Avec beta et alpha ICHEP'04 Aug J. Chauveau - Probing beyond... 33