The photon spectrum in B -> X-s gamma decay, where X-s is any strange hadronic state, is studied using a data sample of 88.5x10(6) e(+)e(-)->Upsilon(4S)-> B(B) over bar decays collected by the BABAR experiment at the Stanford Linear Accelerator Center. The partial branching fraction, Delta B(B -> X-s gamma)=(3.67 +/- 0.29(stat)+/- 0.34(syst)+/- 0.29(model))x10(-4), the first moment < E-gamma >=2.288 +/- 0.025 +/- 0.017 +/- 0.015 GeV, and the second moment < E-gamma(2)>=0.0328 +/- 0.0040 +/- 0.0023 +/- 0.0036 GeV2 are measured for the photon energy range 1.9 GeV < E-gamma < 2.7 GeV. They are also measured for narrower E-gamma ranges. The moments are then fit to recent theoretical calculations to extract the heavy quark expansion parameters m(b) and mu(2)(pi) and to extrapolate the partial branching fraction to E-gamma > 1.6 GeV. In addition, the direct CP asymmetry A(CP)(B -> Xs+d gamma) is measured to be -0.110 +/- 0.115(stat)+/- 0.017(syst).
Measurement of the branching fraction and photon energy moments of B -> X-s gamma and A(CP)(B -> Xs+d gamma)
ANDREOTTI, Mirco;CALABRESE, Roberto;CIBINETTO, Gianluigi;LUPPI, Eleonora;NEGRINI, Matteo;PETRELLA, Antonio;PRENCIPE, Elisabetta;
2006
Abstract
The photon spectrum in B -> X-s gamma decay, where X-s is any strange hadronic state, is studied using a data sample of 88.5x10(6) e(+)e(-)->Upsilon(4S)-> B(B) over bar decays collected by the BABAR experiment at the Stanford Linear Accelerator Center. The partial branching fraction, Delta B(B -> X-s gamma)=(3.67 +/- 0.29(stat)+/- 0.34(syst)+/- 0.29(model))x10(-4), the first moment < E-gamma >=2.288 +/- 0.025 +/- 0.017 +/- 0.015 GeV, and the second moment < E-gamma(2)>=0.0328 +/- 0.0040 +/- 0.0023 +/- 0.0036 GeV2 are measured for the photon energy range 1.9 GeV < E-gamma < 2.7 GeV. They are also measured for narrower E-gamma ranges. The moments are then fit to recent theoretical calculations to extract the heavy quark expansion parameters m(b) and mu(2)(pi) and to extrapolate the partial branching fraction to E-gamma > 1.6 GeV. In addition, the direct CP asymmetry A(CP)(B -> Xs+d gamma) is measured to be -0.110 +/- 0.115(stat)+/- 0.017(syst).I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
