Measurement of the τ Lepton Polarization and R(D
Phys Rev Lett
; 118(21): 211801, 2017 May 26.
Article
em En
| MEDLINE
| ID: mdl-28598663
ABSTRACT
We report the first measurement of the τ lepton polarization P_{τ}(D^{*}) in the decay B[over ¯]âD^{*}τ^{-}ν[over ¯]_{τ} as well as a new measurement of the ratio of the branching fractions R(D^{*})=B(B[over ¯]âD^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]âD^{*}â^{-}ν[over ¯]_{â}), where â^{-} denotes an electron or a muon, and the τ is reconstructed in the modes τ^{-}âπ^{-}ν_{τ} and τ^{-}âρ^{-}ν_{τ}. We use the full data sample of 772×10^{6} BB[over ¯] pairs recorded with the Belle detector at the KEKB electron-positron collider. Our results, P_{τ}(D^{*})=-0.38±0.51(stat)_{-0.16}^{+0.21}(syst) and R(D^{*})=0.270±0.035(stat)_{-0.025}^{+0.028}(syst), are consistent with the theoretical predictions of the standard model.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article