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We report the first evidence for isospin violation in B -> Kgamma and the first measurement of the difference of CP asymmetries between B+->.K(+)gamma and B-0 -> K-*0 gamma. This analysis is based on the data sample containing 772 x 10(6)BB pairs that was collected with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. We find evidence for the isospin violation with a significance of 3.1 sigma, Delta(0+) = [+6.2 +/- 1.5(stat) +/- 0.6(syst) +/- 1.2(f (+-)/f(00))] %, where the third uncertainty is due to the uncertainty on the fraction of B+B- to (BB0)-B-0 production in gamma(4S) decays. The measured value is consistent with predictions of the standard model. The result for the difference of CP asymmetries is Delta A(CP) = [+2.4 +/- 2.8(stat) +/- 0.5(syst)] %, consistent with zero. The measured branching fractions and CP asymmetries for charged and neutral B meson decays are the most precise to date. We also calculate the ratio of branching fractions of B-0 -> K-*0 gamma to B-s(0) -> phi gamma.
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, João Miguel das Neves Duarte, Matthias Wolf, Varun Sharma, Yi Zhang, Tian Cheng, Yixing Chen, Alexis Kalogeropoulos, Ioannis Papadopoulos, Hua Zhang, Siyuan Wang, Xin Chen, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Rakesh Chawla, Jan Steggemann, Konstantin Androsov, Anna Mascellani, Federica Legger, Matteo Galli, Gabriele Grosso
Jian Wang, Matthias Finger, Qian Wang, Yiming Li, João Miguel das Neves Duarte, Matthias Wolf, Varun Sharma, Yi Zhang, Tian Cheng, Yixing Chen, Alexis Kalogeropoulos, Ioannis Papadopoulos, Hua Zhang, Siyuan Wang, Xin Chen, Michele Bianco, Sebastiana Gianì, Sun Hee Kim, Rakesh Chawla, Jan Steggemann, Konstantin Androsov, Anna Mascellani, Federica Legger, Matteo Galli, Gabriele Grosso