2007年5月
Observation of direct CP violation in B-0 ->pi(+)pi(-) decays and model-independent constraints on the quark-mixing angle phi(2)
PHYSICAL REVIEW LETTERS
- 巻
- 98
- 号
- 21
- 開始ページ
- 1
- 終了ページ
- 6
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1103/PhysRevLett.98.211801
- 出版者・発行元
- AMER PHYSICAL SOC
We report a new measurement of the time-dependent CP-violating parameters in B-0 ->pi(+)pi(-) decays with 535x10(6) B (B) over bar pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider operating at the Upsilon(4S) resonance. We find 1464 +/- 65 B-0 ->pi(+)pi(-) events and measure the CP-violating parameters S-pi pi=-0.61 +/- 0.10(stat)+/- 0.04(syst) and A(pi pi)=+0.55 +/- 0.08(stat)+/- 0.05(syst). We observe large direct CP violation with a significance greater than 5 standard deviations for any S-pi pi value. Using isospin relations, we measure the Cabibbo-Kobayashi-Maskawa quark-mixing matrix angle phi(2)=(97 +/- 11)degrees for the solution consistent with the standard model and exclude the range 11 degrees <phi(2)< 79 degrees at the 95% confidence level.
- リンク情報
- ID情報
-
- DOI : 10.1103/PhysRevLett.98.211801
- ISSN : 0031-9007
- eISSN : 1079-7114
- Web of Science ID : WOS:000246776100013