اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدMeasurement of the $bar{B} rightarrow X_s gamma$ Branching Fraction with a Sum of Exclusive Decays
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We use 772$times 10^6$ $B bar{B}$ meson pairs collected at the $Upsilon(4S)$ resonance with the Belle detector to measure the branching fraction for $bar{B} rightarrow X_s gamma$. Our measurement uses a sum-of-exclusives approach in which 38 of the hadronic final states with strangeness equal to $+1$, denoted by $X_s$, are reconstructed. The inclusive branching fraction for $M_{X_s}<$ 2.8 GeV/$c^2$, which corresponds to a minimum photon energy of 1.9 GeV, is measured to be ${cal B}(bar{B} rightarrow X_s gamma)=(3.51pm0.17pm0.33)times10^{-4}$, where the first uncertainty is statistical and the second is systematic.
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