اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدMeasurement of the $D^{ast-}$ polarization in the decay $B^0 to D^{ast -}tau^+ u_{tau}$
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We report the first measurement of the $D^{ast -}$ meson polarization in the decay $B^0 to D^{*-} tau^+ u_{tau}$ using the full data sample of 772$times 10^6$ $Bbar{B}$ pairs recorded with the Belle detector at the KEKB electron-positron collider. Our result, $F_L^{D^ast} = 0.60 pm 0.08 ({rm stat}) pm 0.04 ({rm sys})$, where $F_L^{D^ast}$ denotes the $D^{ast-}$ meson longitudinal polarization fraction, agrees within about $1.7$ standard deviations of the standard model prediction.
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