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arXiv · 1210.1348

Measurements of Branching Fractions and Direct CP Asymmetries for B -> K pi, B->pi pi and B->to KK Decays

Y. -T. Duh·T. -Y. Wu·P. Chang·G. B. Mohanty·Y. Unno·I. Adachi·H. Aihara·D. M. Asner·V. Aulchenko·T. Aushev·T. Aziz·A. M. Bakich·B. Bhuyan·M. Bischofberger·A. Bondar·G. Bonvicini·A. Bozek·M. Bracko·T. E. Browder·Y. Chao·V. Chekelian·A. Chen·P. Chen·B. G. Cheon·I. -S. Cho·K. Cho·V. Chobanova·Y. Choi·Z. Dolezal·A. Drutskoy·D. Dutta·S. Eidelman·H. Farhat·J. E. Fast·A. Frey·V. Gaur·R. Gillard·Y. M. Goh·B. Golob·J. Haba·K. Hayasaka·H. Hayashii·Y. Horii·Y. Hoshi·W. -S. Hou·Y. B. Hsiung·H. J. Hyun·T. Iijima·A. Ishikawa·T. Julius·J. H. Kang·P. Kapusta·T. Kawasaki·H. J. Kim·H. O. Kim·J. H. Kim·M. J. Kim·Y. J. Kim·K. Kinoshita·B. R. Ko·P. Kodys·S. Korpar·P. Krizan·P. Krokovny·T. Kuhr·R. Kumar·T. Kumita·A. Kuzmin·Y. -J. Kwon·S. -H. Lee·Y. Li·J. Libby·C. Liu·Y. Liu·K. Miyabayashi·H. Miyata·R. Mizuk·T. Mori·N. Muramatsu·E. Nakano·M. Nakao·C. Ng·S. Nishida·K. Nishimura·O. Nitoh·S. Ogawa·T. Ohshima·S. Okuno·G. Pakhlova·H. Park·H. K. Park·T. K. Pedlar·R. Pestotnik·M. Petric·L. E. Piilonen·M. Prim·M. Ritter·M. Rohrken·S. Ryu·H. Sahoo
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Abstract

We report measurements of the branching fractions and direct CP asymmetries (A_{CP}) for B->K pi, pi pi and KK decays (but not pi^0 pi^0) based on the final data sample of 772x10^6 B B-bar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+ e^- collider. We set a 90% confidence-level upper limit for K^+- K^-+ at 2.0x10^{-7}; all other decays are observed with branching fractions ranging from 10^{-6} to 10^{-5}. In the $B^0/B^0-bar -> K^+-π^-+ mode, we confirm Belle's previously reported large A_{CP} with a value of -0.069 +- 0.014 +- 0.007 and a significance of 4.4 sigma. For all other flavor-specific modes, we find A_{CP} values consistent with zero, including A_{CP}(K^+- π^0) = +0.043 +- 0.024 +- 0.007 with 1.8 sigma significance. The difference of CP asymmetry between B^+- -> K^+- pi^0 and B^0/B^0-bar -> K^+-π^-+ is found to be Delta A_{K pi} equiv A_{CP} (K^+ pi^0) - A_{CP}(K^+ pi^-) = +0.112 +- 0.027 +- 0.007 with 4.0 sigma significance. We also calculate the ratios of partial widths for the B-> K pi decays. Using our results, we test the validity of the sum rule A_{CP}(K^+ pi^-) + A_{CP}(K^0π^+) x Gamma(K^0π^+)/Gamma(K^+ pi^-)} - A_{CP}(K^+ pi^0)x 2Gamma(K^+ pi^0)/Gamma(K^+ pi^-) - A_{CP}(K^0 pi^0)x 2Gamma(K^0 pi^0)/Gamma(K^+ pi^-) = 0 and obtain a sum of -0.270 +- 0.132 +- 0.060 with 1.9 sigma significance.

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Y. -T. Duh, T. -Y. Wu, P. Chang, G. B. Mohanty, Y. Unno, I. Adachi, H. Aihara, D. M. Asner, V. Aulchenko, T. Aushev, T. Aziz, A. M. Bakich, B. Bhuyan, M. Bischofberger, A. Bondar, G. Bonvicini, A. Bozek, M. Bracko, T. E. Browder, Y. Chao, V. Chekelian, A. Chen, P. Chen, B. G. Cheon, I. -S. Cho, K. Cho, V. Chobanova, Y. Choi, Z. Dolezal, A. Drutskoy, D. Dutta, S. Eidelman, H. Farhat, J. E. Fast, A. Frey, V. Gaur, R. Gillard, Y. M. Goh, B. Golob, J. Haba, K. Hayasaka, H. Hayashii, Y. Horii, Y. Hoshi, W. -S. Hou, Y. B. Hsiung, H. J. Hyun, T. Iijima, A. Ishikawa, T. Julius, J. H. Kang, P. Kapusta, T. Kawasaki, H. J. Kim, H. O. Kim, J. H. Kim, M. J. Kim, Y. J. Kim, K. Kinoshita, B. R. Ko, P. Kodys, S. Korpar, P. Krizan, P. Krokovny, T. Kuhr, R. Kumar, T. Kumita, A. Kuzmin, Y. -J. Kwon, S. -H. Lee, Y. Li, J. Libby, C. Liu, Y. Liu, K. Miyabayashi, H. Miyata, R. Mizuk, T. Mori, N. Muramatsu, E. Nakano, M. Nakao, C. Ng, S. Nishida, K. Nishimura, O. Nitoh, S. Ogawa, T. Ohshima, S. Okuno, G. Pakhlova, H. Park, H. K. Park, T. K. Pedlar, R. Pestotnik, M. Petric, L. E. Piilonen, M. Prim, M. Ritter, M. Rohrken, S. Ryu, H. Sahoo. 2013-05-02. Measurements of Branching Fractions and Direct CP Asymmetries for B -> K pi, B->pi pi and B->to KK Decays. https://doi.org/10.1103/physrevd.87.031103

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