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


Doll, David Andrew (2011) Measurement of the Rare Transition b→sγ Using the Complete BABAR Data Set. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/E6S9-4D28.


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- -> Xsγ)=(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.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Particle Physics; Flavor Physics; Flavor Changing Neutral Current; Rare Quark Transitions; Rare B Decays
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Awards:Lucy Guernsey Service Award, 2010. Graduate Deans’ Award for Outstanding Community Service, 2011.
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Hitlin, David G.
Thesis Committee:
  • Hitlin, David G. (chair)
  • Porter, Frank C.
  • Wise, Mark B.
  • Filippone, Bradley W.
Defense Date:26 May 2011
Record Number:CaltechTHESIS:05312011-194358237
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6484
Deposited By: David Doll
Deposited On:07 Sep 2012 16:29
Last Modified:09 Oct 2019 17:11

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