Measurement of the Branching Fraction and Photon Energy Moments of B{yields}X{sub s}{gamma} and A{sub CP}(B{yields}X{sub s+d}{gamma})

Journal Article · Fri Oct 27 00:00:00 EDT 2006 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.97.171803· OSTI ID:20861036

Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A ^[1]; Grauges, E ^[2]; Palano, A ^[3]; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S ^[4]; Eigen, G; Ofte, I; Stugu, B ^[5]

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1. Laboratoire de Physique des Particules, F-74941 Annecy-le-Vieux (France)
2. Universitat de Barcelona, Facultat de Fisica Dept. ECM, E-08028 Barcelona (Spain)
3. Universita di Bari, Dipartimento di Fisica and INFN, I-70126 Bari (Italy)
4. Institute of High Energy Physics, Beijing 100039 (China)
5. University of Bergen, Institute of Physics, N-5007 Bergen (Norway)

The photon spectrum in B{yields}X{sub s}{gamma} decay, where X{sub s} is any strange hadronic state, is studied using a data sample of 88.5x10{sup 6} e{sup +}e{sup -}{yields}{upsilon}(4S){yields}BB decays collected by the BABAR experiment at the Stanford Linear Accelerator Center. The partial branching fraction, {delta}B(B{yields}X{sub s}{gamma})=(3.67{+-}0.29(stat){+-}0.34(syst){+-}0.29(model))x10{sup -4}, the first moment <E{sub {gamma}}>=2.288{+-}0.025{+-}0.017{+-}0.015 GeV, and the second moment <E{sub {gamma}}{sup 2}>=0.0328{+-}0.0040{+-}0.0023{+-}0.0036 GeV{sup 2} are measured for the photon energy range 1.9 GeV<E{sub {gamma}}<2.7 GeV. They are also measured for narrower E{sub {gamma}} ranges. The moments are then fit to recent theoretical calculations to extract the heavy quark expansion parameters m{sub b} and {mu}{sub {pi}}{sup 2} and to extrapolate the partial branching fraction to E{sub {gamma}}>1.6 GeV. In addition, the direct CP asymmetry A{sub CP}(B{yields}X{sub s+d}{gamma}) is measured to be -0.110{+-}0.115(stat){+-}0.017(syst)

• OSTI ID: 20861036
• Journal Information: Physical Review Letters, Vol. 97, Issue 17; Other Information: DOI: 10.1103/PhysRevLett.97.171803; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0031-9007
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANNIHILATION
ASYMMETRY
B MESONS
B QUARKS
BRANCHING RATIO
C QUARKS
ELECTRON-POSITRON INTERACTIONS
ELECTRONS
GEV RANGE 01-10
PARTICLE DECAY
PHOTONS
POSITRONS
STANFORD LINEAR ACCELERATOR CENTER
T QUARKS