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Title: Electromagnetic dipole operator effect on B{yields}X{sub s}{gamma} at O({alpha}{sub s}{sup 2})

Abstract

The flavor-changing electromagnetic dipole operator O{sub 7} gives the dominant contribution to the B{yields}X{sub s}{gamma} decay rate. We calculate two-loop QCD corrections to its matrix element together with the corresponding bremsstrahlung contributions. The optical theorem is applied, and the relevant imaginary parts of three-loop diagrams are computed following the lines of our recent t{yields}X{sub b}W calculation. The complete result allows us to test the validity of the naive non-Abelianization (NNA) approximation that has been previously applied to estimate the next-to-next-to-leading order QCD correction to {gamma}(B{yields}X{sub s}{gamma})/{gamma}(B{yields}X{sub u}e{nu}). When both decay widths are normalized to m{sub b,R}{sup 5} in the same renormalization scheme R, the calculated O({alpha}{sub s}{sup 2}) correction is sizable ({approx}6%), and the NNA estimate is about 1/3 too large. On the other hand, when the ratio of the decay widths is written as Sxm{sub b,MS}{sup 2}(m{sub b})/m{sub b,pole}{sup 2}, the calculated O({alpha}{sub s}{sup 2}) correction to S is at the level of 1% for both the complete and the NNA results.

Authors:
 [1];  [1];  [2];  [1];  [3]
  1. Department of Physics, University of Alberta, Edmonton, AB T6G 2J1 (Canada)
  2. Institute of Theoretical Physics, Warsaw University, 00-681 Warsaw (Poland)
  3. Institute for Nuclear Research, Russian Academy of Sciences, Moscow, 117312 (Russian Federation)
Publication Date:
OSTI Identifier:
20711204
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 72; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevD.72.033014; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B MESONS; BREMSSTRAHLUNG; CORRECTIONS; DIPOLES; FEYNMAN DIAGRAM; FLAVOR MODEL; LEPTONIC DECAY; MATRIX ELEMENTS; OPTICAL THEOREM; PARTICLE WIDTHS; PHOTONS; QUANTUM CHROMODYNAMICS; QUARKS; RENORMALIZATION

Citation Formats

Blokland, I, Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Czarnecki, A, Misiak, M, Slusarczyk, M, Institute of Physics, Jagiellonian University, 30-059 Cracow, and Tkachov, F. Electromagnetic dipole operator effect on B{yields}X{sub s}{gamma} at O({alpha}{sub s}{sup 2}). United States: N. p., 2005. Web. doi:10.1103/PhysRevD.72.033014.
Blokland, I, Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Czarnecki, A, Misiak, M, Slusarczyk, M, Institute of Physics, Jagiellonian University, 30-059 Cracow, & Tkachov, F. Electromagnetic dipole operator effect on B{yields}X{sub s}{gamma} at O({alpha}{sub s}{sup 2}). United States. https://doi.org/10.1103/PhysRevD.72.033014
Blokland, I, Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2, Czarnecki, A, Misiak, M, Slusarczyk, M, Institute of Physics, Jagiellonian University, 30-059 Cracow, and Tkachov, F. 2005. "Electromagnetic dipole operator effect on B{yields}X{sub s}{gamma} at O({alpha}{sub s}{sup 2})". United States. https://doi.org/10.1103/PhysRevD.72.033014.
@article{osti_20711204,
title = {Electromagnetic dipole operator effect on B{yields}X{sub s}{gamma} at O({alpha}{sub s}{sup 2})},
author = {Blokland, I and Department of Physics and Astronomy, University of Victoria, Victoria, BC V8P 5C2 and Czarnecki, A and Misiak, M and Slusarczyk, M and Institute of Physics, Jagiellonian University, 30-059 Cracow and Tkachov, F},
abstractNote = {The flavor-changing electromagnetic dipole operator O{sub 7} gives the dominant contribution to the B{yields}X{sub s}{gamma} decay rate. We calculate two-loop QCD corrections to its matrix element together with the corresponding bremsstrahlung contributions. The optical theorem is applied, and the relevant imaginary parts of three-loop diagrams are computed following the lines of our recent t{yields}X{sub b}W calculation. The complete result allows us to test the validity of the naive non-Abelianization (NNA) approximation that has been previously applied to estimate the next-to-next-to-leading order QCD correction to {gamma}(B{yields}X{sub s}{gamma})/{gamma}(B{yields}X{sub u}e{nu}). When both decay widths are normalized to m{sub b,R}{sup 5} in the same renormalization scheme R, the calculated O({alpha}{sub s}{sup 2}) correction is sizable ({approx}6%), and the NNA estimate is about 1/3 too large. On the other hand, when the ratio of the decay widths is written as Sxm{sub b,MS}{sup 2}(m{sub b})/m{sub b,pole}{sup 2}, the calculated O({alpha}{sub s}{sup 2}) correction to S is at the level of 1% for both the complete and the NNA results.},
doi = {10.1103/PhysRevD.72.033014},
url = {https://www.osti.gov/biblio/20711204}, journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 3,
volume = 72,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 2005},
month = {Mon Aug 01 00:00:00 EDT 2005}
}