Portal de Periódicos da CAPES

Observation of Time-Dependent C P Violation in B 0 → η ′ K 0 Decays and Improved Measurements of<mml:math xmlns:mml="http://…

2007; American Physical Society; Volume: 98; Issue: 3 Linguagem: Inglês

10.1103/physrevlett.98.031802

1092-0145

K. F. Chen, K. Hara, M. Hazumi, T. Higuchi, K. Miyabayashi, Y. Nakahama, K. Sumisawa, O. Tajima, Y. Ushiroda, Y. Yusa, K. Abe, K. Abe, I. Adachi, H. Aihara, D. Anipko, K. Arinstein, K. F. Chen, T. Aushev, T. Aziz, A. M. Bakich, V. Balagura, S. Banerjee, E. L. Barberio, M. Barbero, A. Bay, K. Belous, U. Bitenc, I. Bizjak, S. Blyth, A. Bondar, A. Bożek, M. Bračko, J. Brodzicka, T. E. Browder, P. Chang, Y. Chao, A. Chen, W T Chen, B. G. Cheon, R. Chistov, S.-K. Choi, Y. Choi, Y. Choi, A. Chuvikov, S. Cole, J. Dalseno, M. Danilov, M. Dash, J. Dragic, A. Drutskoy, S. Eidelman, D. Epifanov, S. Fratina, A. Garmash, T. Gershon, A. Go, G. Gokhroo, P. Goldenzweig, B. Golob, H. Ha, J. Haba, T. Hara, K. Hayasaka, H. Hayashii, D. Heffernan, T. Hokuue, Y. Hoshi, S. Hou, W.-S. Hou, Y. Hsiung, T. Iijima, K. Ikado, A. Imoto, K. Inami, A. Ishikawa, H. Ishino, R. Itoh, M. Iwasaki, M. Iwasaki, H. Kakuno, J. H. Kang, S.U. Kataoka, N. Katayama, H. Kawai, T. Kawasaki, H. R. Khan, H. Kichimi, H J Kim, S. K. Kim, Y. J. Kim, K. Kinoshita, S. Korpar, P. Križan, P. Krokovny, R. Kulasiri, R. Kumar, Chou-Pin Kuo, A. Kusaka, A. Kuzmin, YJ Kwon, G. Leder, J. Lee, M. J. Lee, T. Lesiak, Jian Li, A. Limosani, S.-W. Lin, Y. Liu, D. Liventsev, D. Majumder, F. Mandl, T. Matsumoto, A. Matyja, W. Mitaroff, H. Miyake, H. Miyata, Y. Miyazaki, R. Mizuk, D. Mohapatra, G. R. Moloney, A. Murakami, T. Nagamine, Y. Nagasaka, I. Nakamura, E. Nakano, M. Nakao, Z. Natkaniec, S. Nishida, O. Nitoh, S. Noguchi, T. Nozaki, S. Ogawa, T. Ohshima, S. Okuno, S. L. Olsen, Y. Onuki, W. Ostrowicz, H. Ozaki, P. Pakhlov, G. Pakhlova, H. Pałka, H. Park, R. Pestotnik, L. E. Piilonen, H. Sahoo, Y. Sakai, N. Satoyama, T. Schietinger, O. Schneider, J. Schümann, A. J. Schwartz, R. Seidl, K. Senyo, M. E. Sevior, M. Shapkin, H. Shibuya, B. Shwartz, J. B. Singh, A. Sokolov, A. Somov, S. Stanič, M. Starič, H. Stoeck, T. Sumiyoshi, S. Suzuki, F. Takasaki, K. Tamai, N. Tamura, M. Tanaka, G. N. Taylor, Y. Teramoto, X.C. Tian, K. Trabelsi, T. Tsuboyama, T. Tsukamoto, S. Uehara, T. Uglov, K. Ueno, Y. Unno, S. Uno, P. Urquijo, Y. Usov, G. Varner, K. E. Varvell, S. Villà, Chi Chiu Wang, C H Wang, M.-Z. Wang, Y. Watanabe, R. Wedd, E. Won, Qiongtao Xie, B. Yabsley, A. Yamaguchi, Y. Yamashita, M. Yamauchi, C. C. Zhang, Z. P. Zhang, V. Zhilich, A. Zupanc,

Quantum Chromodynamics and Particle Interactions

We present improved measurements of $CP$-violation parameters in ${B}^{0}\ensuremath{\rightarrow}\ensuremath{\phi}{K}^{0}$, ${\ensuremath{\eta}}^{\ensuremath{'}}{K}^{0}$, ${K}_{S}^{0}{K}_{S}^{0}{K}_{S}^{0}$ decays based on a sample of $535\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected at the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB energy-asymmetric ${e}^{+}{e}^{\ensuremath{-}}$ collider. We obtain $\mathrm{sin}2{\ensuremath{\phi}}_{1}^{\mathrm{eff}}=+0.64\ifmmode\pm\else\textpm\fi{}0.10(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.04(\mathrm{syst})$ for ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{K}^{0}$, $+0.50\ifmmode\pm\else\textpm\fi{}0.21(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.06(\mathrm{syst})$ for ${B}^{0}\ensuremath{\rightarrow}\ensuremath{\phi}{K}^{0}$, and $+0.30\ifmmode\pm\else\textpm\fi{}0.32(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.08(\mathrm{syst})$ for ${B}^{0}\ensuremath{\rightarrow}{K}_{S}^{0}{K}_{S}^{0}{K}_{S}^{0}$ decays. We have observed $CP$ violation in the ${B}^{0}\ensuremath{\rightarrow}{\ensuremath{\eta}}^{\ensuremath{'}}{K}^{0}$ decay with a significance of 5.6 standard deviations. We also perform an improved measurement of $CP$ asymmetries in ${B}^{0}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{0}$ decays and obtain $\mathrm{sin}2{\ensuremath{\phi}}_{1}=+0.642\ifmmode\pm\else\textpm\fi{}0.031(\mathrm{stat})\ifmmode\pm\else\textpm\fi{}0.017(\mathrm{syst})$.