Measurement of the Rare Transition b→sγ Using the Complete BABAR Data Set

Author: Doll, David Andrew

Year: 2011

Degree: Dissertation (Ph.D.)

Advisor: Hitlin, David G.

Committee Members: Hitlin, David G.; Porter, Frank C.; Wise, Mark B.; Filippone, Bradley W.

Option: Physics

DOI: 10.7907/E6S9-4D28

Abstract

We present the results of a measurement of the total rate and photon energy spectrum in b -> sγ transitions using the entire BABAR data set, 429 fb^-1. These results use a "sum of exclusives" approach in which we reconstruct a subset of the final states of the s-quark system and correct for the final states that are missing. We find B(B^- -> X_sγ)=(329 ± 19 ± 48)x10^-6 for Eγ>1.9 GeV. We also measure the mean and variance of the photon spectrum and find <E>=2.346 ± 0.018^+0.027_-0.022 and <E²> - <E>² = 0.0211 ± 0.0057^+0.0055_-0.0069. Finally we fit two classes of models for the photon spectrum and extract their respective HQET parameters.

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