اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدMeasurement of the direct $CP$ asymmetry in $bar{B}rightarrow X_{s+d}gamma$ decays with a lepton tag
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We report the measurement of the direct $CP$ asymmetry in the radiative $bar{B}rightarrow X_{s+d}gamma$ decay using a data sample of $(772 pm 11)times 10^6$ $Bbar{B}$ pairs collected at the $Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The $CP$ asymmetry is measured as a function of the photon energy threshold. For $E^{rm{*}}_{gamma} geq 2.1~{rm{GeV}}$, where $E^{rm{*}}_{gamma}$ is the photon energy in the center-of-mass frame, we obtain $mathcal{A}_{CP}(bar{B}rightarrow X_{s+d}gamma)= (2.2 pm 3.9 pm 0.9) %$, consistent with the Standard Model prediction.
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