Observation of BâD(*) π
Phys Rev Lett
; 116(4): 041801, 2016 Jan 29.
Article
in En
| MEDLINE
| ID: mdl-26871322
ABSTRACT
We report on measurements of the decays of B¯ mesons into the semileptonic final states B¯âD^(*)π^(+)π^(-)â^(-)ν¯, where D^(*) represents a D or D^(*) meson and â^(-) is an electron or a muon. These measurements are based on 471×10^(6) BB ¯ pairs recorded with the BABAR detector at the SLAC asymmetric B factory PEP-II. We determine the branching fraction ratios R_{π^{+}π^{-}}^{(*)}=B(B[over ¯]âD^{(*)}π^{+}π^{-}â^{-}ν[over ¯])/B(B[over ¯]âD^{(*)}â^{-}ν[over ¯]) using events in which the second B meson is fully reconstructed. We find R_{π^{+}π^{-}}=0.067±0.010±0.008 and R_{π^{+}π^{-}}^{*}=0.019±0.005±0.004, where the first uncertainty is statistical and the second is systematic. Based on these results and assuming isospin invariance, we estimate that B[over ¯]âD^{(*)}ππâ^{-}ν[over ¯] decays, where π denotes either a π^{±} and π^{0} meson, account for up to half the difference between the measured inclusive semileptonic branching fraction to charm hadrons and the corresponding sum of previously measured exclusive branching fractions.
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01-internacional
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MEDLINE
Language:
En
Journal:
Phys Rev Lett
Year:
2016
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Article
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