Time-dependent CPV in B η'ks η

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1 B ± ωk ω ± /π ± and Time-dependen CPV in B η'ks η a Belle Kai-Feng Chen Naional Taiwan Universiy The Belle Collaboraion Flavor Physics & CP Violaion(FPCP) Universiy of Pennsylvania, Philadelphia May 16-18, Inroducion B ± ωk ± CP in B η'ks Summary

2 Inoducion Rare B decays are useful o deermine he uniary riangle. Tes of curren undersanding of B physics. Search for CP violaion and probe new physics. B π l ν B D S π V ud V * ub B ππ B ρπ φ (α) B-B mixing V d V * b φ 3 (γ) B DK B ππ/kπ B ωk Oher charmless B decays V cd V * cb B D(*) l ν φ 1 (β) B J/ψK B D(*)D(*) B η'k

3 B ± ωh ± Inroducion b B u b B u W W u,c, g u d, s u u s u u u π, K ω K ω B ± ωh ± can es B decay models. Useful o search for direc CP violaion. Brief Hisory: CLEO firs repored he B ± ωk ± decay branching fracions in [PRL 81, 7(1998)] B ± ωπ ± is found o be larger han ωk ± wih new daa se. [PRL 8, 881()] BaBar confirms B ± ωπ ± >ωk ±. [PRL 87, 18(1)] (B ωπ)x1-6 (B ωκ)x1-6 7 CLEO(1998) < CLEO().9 1. < BaBar(1) < 1..3

4 B ± ωh ± Resuls Resuls from 31.9M BB pairs. Yields are exraced by a -dimensional unbinned likelihood mehod. Background from B decays Enries / MeV Enries / MeV E (GeV) 7.. Enries / MeV Enries / MeV Mb (GeV) Preliminary B ± ωk ± B ± ωπ ± E (GeV) Mb (GeV) Yield Σ ε B(x1-6 ) U.L B ωπ σ 7.7% 1.8. <8. B ωκ σ 6.3%. 1. -

5 Consisency Checks ωmass Evens / MeV Evens / MeV ω mass (GeV) 1 1 (a) (c) B ωk B ωπ (b) (d) coshel (a) A clear ω peak shown in π + π π specrum wih B candidae. (b) The ω heliciy angle disribuion maches P VP decay. (c),(d) By removing he KID requiremen, he E disribuion is consisen wih ωk and ωπ yields de (GeV) kid vs E

6 Direc CPV in B ± ωk ± Search for Acp in B ± ωk ± mode. K Acp(= ) = -.±.7±. K K 9% C.L.) K Enries / MeV Enries / MeV 3 1 B ωk - 7.±3. evens Enries / MeV ωk E (GeV) - Enries / MeV ωk Mb (GeV) - 6 Preliminary B ωk ±3.7 evens ωk E (GeV) ωk Mb (GeV) +

7 1. 3. Summary of B ± ωh ± We have observed B ± ωk ±, and evidence for B ± ωπ ± (ωk ± ) = (9.9 ±1.) x 1-6 (6.σ) (ωπ ± ) = (.3 ±.) x 1-6 (3.3σ) < 8. x 1-6 Compare resuls wih oher experimens: (B ωπ)x1-6 (B ωκ)x Belle() < BaBar(1) < CLEO() <8.8 Acp(ωK ± ) = -.±.7±. 9% C.L.).9 1.9

8 A S CPV in B η'k Wihin he SM, B η'k consiss of penguin process and conribuion from ree diagrams...,ec. The ime-dependen CP asymmery can be expressed as: A CP B B B B cos m S sin m sin m sin 1 NP sin m ( If A = )

9 Time-dependen Measuremen B B Ks η' daughers cp-side B B B B z = βγc l K ag-side/mdlh mehod B B X l X l, XD D, XD D YK YK,...,... Fully reconsruc B η'ks as cp-side.(η'k ± as conrol sample) The b-flavor is deermined by he accompanying B meson(bag) by a muli-dimensional likelihood mehod(mdlh). Deermine he CP parameers from he disribuion by an unbinned likelihood fi.

10 B η'k Reconsrucion Daa se for his analysis is fb -1. Two sub decay modes of η' are reconsruced: η' ηππ and η' ργ. A unbinned -dimensional likelihood fi is performed. Enries η'k + η'ks GeV E GeV/C Preliminary Mb η' ηππ Combined expeced BB background N(ηππ K + ) = 78. N(ργ K + )= 1 ±1 N(ηππ Ks)= 7. N(ργ Ks) =

11 Consisency Checks Checks by B-lifeime fi wih 9 η'k ± and 73 η'ks evens: BB + qq coninuum BB only B ± B ps z(rec)/(βγ) Ψ C CP-fi wih non-asymmeric sample: η'k ± ps z(rec)/(βγ) Ψ C Enries/ps τ(b ± ) = ps (PDG: 1.63±.8 ps) +.31 τ(b ) = ps (PDG: 1.8±.3 ps) q = +1 q = - 1 sin(φ 1 +φ NP ) = S(η'K ± ) =.11±.9 A(η'K ± ) = -.7± ps (ps) Asymmery ± 1σ error

12 Time-dependen Acp CP-fi is performed wih 73 η'ks signal candidaes. Enries/ps 1 (a) q = +1 S(η'Ks) = A(η'Ks) =.1±.3 3 (b) q = - 1 If A(η'Ks) is se o be zero: +.3 sin(φ 1 +φ NP ) =.9 -. Firs measuremen of imedependen CPV in B η'ks decay. Probe phases from New Physics. 1 1 (c) q = +1 q = (d) η K S ± 1σ error ps Asymmery (ps) Preliminary

13 Sysemaic Uncerainies Sysemaic uncerainies are deermined by repeaing fi on daa wih ±1σ o each parameers. Sysemaic uncerainies include S(η'Ks) A(η'Ks) sin(φ1+φ NP ) Verexing/rack selecion +./ /-.3 +./-. Physics parameers +.3/ /-. +./-.3 Wag fracions +.3/ / /-. Resoluion funcion +./ /-.1 +./-.3 PDF funcions +.3/ /-. +./-. Even fracions +./-. +.1/-.1 +./-. BB background +./-. +./-.1 +./-.1 Sum +.7/ / /-.7 Preliminary

14 Summary of CPV in η'k Firs measuremen of ime-dependen CPV parameers in B η'ks decay Probe for phases from New Physics S(η'Ks) =.7 (sa.) ±.7(sys.) A(η'Ks) =.1 ±.3(sa.) ±.7(sys.) If A(η'Ks) se o be zero: +.3 sin(φ 1 +φ NP ) =.9 -. (sa.) ±.7(sys.) Belle sin(φ 1 ) =.8 ±.1(sa.) ±.(sys.) Preliminary

15 Conclusion B ± ωh ± We have observed B ωk ± Evidence for B ωπ ±. Firs look a direc CPV in B ωk ±. CP in B η'k Firs measuremen of imedependen CPV in B η'ks decay. Perspecives More daa are coming soon 8 fb -1 per monh. 9fb -1 for summer ±.3 for 9fb -1 saisical error ±.1 for 3fb fb-1 Saisical Error VS. Luminosiy