Precision measurement of the B â Xs γ photon energy spectrum, branching fraction, and direct CP asymmetry A(CP)((B â X(s+d)γ).
Phys Rev Lett
; 109(19): 191801, 2012 Nov 09.
Article
em En
| MEDLINE
| ID: mdl-23215373
ABSTRACT
The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B â X(s)γ plus B â X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) â BB decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B â X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B â X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.
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MEDLINE
Assunto principal:
Fótons
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Modelos Teóricos
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Física Nuclear
Idioma:
En
Ano de publicação:
2012
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Article