1998/09/14 by Matthias Neubert, Neubert, Matthias
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Nuclear physics research studies #Particle Detector Development and Performance #Radiation Detection and Scintillator Technologies #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9809377
6 pages, 1 figure, uses ltwol2e.sty (included); to appear in the Proceedings of the 29th International Conference on High Energy Physics (Vancouver)
arxiv created 1998/09/14 · openalex publication_date 1998/09/14 · arxiv updated 2009/11/30 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
We review the theoretical understanding of the branching ratio and photon-energy spectrum in B -> Xs gamma decays at next-to-leading order in QCD, including consistently the effects of Fermi motion. For the Standard Model, we obtain B(B -> Xs gamma)=(3.29 +- 0.33)*10-4 for the total branching ratio, and B(B -> Xs gamma)=(2.85+0.34-0.40)*10-4 if a cut Egamma > 2.1 GeV is applied on the photon energy, as done in the recent CLEO analysis. A precise measurement of the photon spectrum would help reducing the theoretical uncertainty and yield important information on the momentum distribution of b quarks inside B mesons.