Evidence for Isospin Violation and Measurement of CP Asymmetries in BâK
Phys Rev Lett
; 119(19): 191802, 2017 Nov 10.
Article
em En
| MEDLINE
| ID: mdl-29219495
ABSTRACT
We report the first evidence for isospin violation in BâK^{*}γ and the first measurement of the difference of CP asymmetries between B^{+}âK^{*+}γ and B^{0}âK^{*0}γ. This analysis is based on the data sample containing 772×10^{6}BB[over ¯] pairs that was collected with the Belle detector at the KEKB energy-asymmetric e^{+}e^{-} collider. We find evidence for the isospin violation with a significance of 3.1σ, Δ_{0+}=[+6.2±1.5(stat)±0.6(syst)±1.2(f_{+-}/f_{00})]%, where the third uncertainty is due to the uncertainty on the fraction of B^{+}B^{-} to B^{0}B[over ¯]^{0} production in Ï(4S) decays. The measured value is consistent with predictions of the standard model. The result for the difference of CP asymmetries is ΔA_{CP}=[+2.4±2.8(stat)±0.5(syst)]%, consistent with zero. The measured branching fractions and CP asymmetries for charged and neutral B meson decays are the most precise to date. We also calculate the ratio of branching fractions of B^{0}âK^{*0}γ to B_{s}^{0}âÏγ.
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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