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Charmless hadronic B s Decays. The study of. Cai-Dian Lü (IHEP, Beijing). hep-ph/0703162. Thanks Ali, Kramer and Li, Shen,Wang. Outline. Introduction and motivation BRs and Direct CP asymmetry Test of SU(3) breaking by charmless B 0 and B s decays in pQCD approach
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Charmless hadronic Bs Decays The study of Cai-Dian Lü (IHEP, Beijing) hep-ph/0703162 Thanks Ali, Kramer and Li, Shen,Wang Moriond
Outline • Introduction and motivation • BRs and Direct CP asymmetry • Test of SU(3) breaking by charmless B0 and Bs decays in pQCD approach • Some Bs channels for /3 measurement • Summary Moriond
Picture of PQCD Approach 4-quark operator b Six quark interaction inside the dotted line Moriond
pQCD approach based on kT factorization Do not need form factor inputs • All diagrams using the same wave functions • (same order in sexpansion) • All channels use the same wave functions • Number of parameters reduced Moriond
CP Violation in B (K)(real prediction before exp.) (2001) Moriond
pQCD approach in B decays • pQCD approach successfully describe the B0 and B+ decays • Most of the branching ratios agree well with experiments • The right direct CP asymmetry sign with the experiment Using the constrained parameters determined here to predict Bs decays Moriond
Bs distribution amplitude b=0.45 b =0.50 b =0.55 b=0.4 GeV for B meson = momentum fraction Moriond
Form factors derived from light cone wave functions Larger fBs, but smaller inverse moment of Bs meson distribution amplitude QCDF: Moriond
BR (x 10–6) Moriond
BR (x 10–6) Moriond
Bs PV BR (x 10–6) Moriond
Bs VV BR (x 10–6) Moriond
Bs PV BR (x 10–6) Moriond
Three measurements of BRs in Bs SCET QCDF PQCD EXP CDF BsK– pi+ 4.9±1.8 10±6 11 ±6 5.0±1.3 BsK– K+ 18±7 23±27 17 ±9 24 ± 5 Bsphi phi 22 ±30 33 ±13 14 ± 8 |Vub| (10–3) = 3.69 4.31 34 Moriond
First measurement of CP in Bs BsK– pi+ SCET QCDF PQCD EXP 20 ± 26 –6.7 ± 1630 ± 6 39 ± 15 ± 8 pQCD agree with EXP in CP Moriond
vs A Moriond
vs S Moriond
LO pQCD vs AK Moriond
NLO pQCD vs AK Moriond
U-spin symmetry (Gronau,Rosner,Lipkin) = –1 • Results from pQCD • Experimental data = 0 Moriond
R3 vs Red area is pQCD prediction; Shaded area is exp. Moriond
SU(3) symmetry + u Bd(s) –(K–) d(s) Only leading contribution is related by simple SU(3) Moriond
U-spin, SU(3) • T = tree PA = penguin annihilation • P = QCD penguin PEW= color suppressed • E = W exchange electroweak penguin Moriond
SU(3) breaking and relative size of different contributions • CKM matrix elements already factored out • SU(3) breaking is not negligible Moriond
Bs 0 KS • If tree dominant (Vub), good for gamma measuremnt. • However, Color suppressed tree is comparable with QCD penguin contribution • Direct CP large QCDF PQCD 25 ± 60 % 97 ± 30 % Not good for gamma measurement Moriond
Bs 0 (Fleischer 1994) • I = 0 I = 1 • I = 1 • Both tree and electroweak penguin can give I = 1 (QCD penguin I =0) • Like B+ pi+pi0, only I =3/2 • There should be only one strong phase, then no relative strong phase between amplitudes Moriond
Bs 0 • Color suppressed tree is comparable with electroweak penguin contribution • Direct CP small QCDF PQCD 27±40 % 9 ± 2 % good for /3 measurement QCDF PQCD BR(10–7) 1.2 2.0 Moriond
Polarizations Moriond
Summary • PQCD can give the right sign for CP asymmetry the strong phase from PQCD should be the dominant one. • The SU(3) breaking effects are not very small as expected Moriond
Thank you! Moriond