We present a measurement of the branching fraction and photon-energy spectrum for the decay B -> X(s)gamma using data from the BABAR experiment. The data sample corresponds to an integrated luminosity of 210 fb(-1), from which approximately 680 000 B (B) over bar events are tagged by a fully reconstructed hadronic decay of one of the B mesons. In the decay of the second B meson, an isolated high-energy photon is identified. We measure B(B -> X(s)gamma) = (3.66 +/- 0.85(stat) +/- 0.60(syst)) x 10(-4) for photon energies E(gamma) above 1.9 GeV in the B rest frame. From the measured spectrum we calculate the first and second moments for different minimum photon energies, which are used to extract the heavy-quark parameters m(b) and mu(2)(pi). In addition, measurements of the direct CP asymmetry and isospin asymmetry are presented.
Measurement of the B -> X(s)gamma branching fraction and photon energy spectrum using the recoil method
CALDERINI, GIOVANNI;ANGELINI, CARLO;BATIGNANI, GIOVANNI;BETTARINI, STEFANO;CARPINELLI, MASSIMO;CERVELLI, ALBERTO;FORTI, FRANCESCO;GIORGI, MARCELLO;MARCHIORI, GIOVANNI;NERI, NICOLA;PAOLONI, EUGENIO;RIZZO, GIULIANA;
2008-01-01
Abstract
We present a measurement of the branching fraction and photon-energy spectrum for the decay B -> X(s)gamma using data from the BABAR experiment. The data sample corresponds to an integrated luminosity of 210 fb(-1), from which approximately 680 000 B (B) over bar events are tagged by a fully reconstructed hadronic decay of one of the B mesons. In the decay of the second B meson, an isolated high-energy photon is identified. We measure B(B -> X(s)gamma) = (3.66 +/- 0.85(stat) +/- 0.60(syst)) x 10(-4) for photon energies E(gamma) above 1.9 GeV in the B rest frame. From the measured spectrum we calculate the first and second moments for different minimum photon energies, which are used to extract the heavy-quark parameters m(b) and mu(2)(pi). In addition, measurements of the direct CP asymmetry and isospin asymmetry are presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
