Exclusive radiative decays of {upsilon} in soft-collinear effective theory

Journal Article · Fri Apr 01 04:00:00 EST 2005 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PhysRevD.71.074002· OSTI ID:20708973

Fleming, Sean; Lee, Christopher; Leibovich, Adam K ^[1]

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1. Department of Physics, University of California at San Diego, La Jolla, California 92093 (United States)

We study exclusive radiative decays of the {upsilon} using soft-collinear effective theory and nonrelativistic QCD. In contrast to inclusive radiative decays at the endpoint we find that color-octet contributions are power suppressed in exclusive decays, and can safely be neglected, greatly simplifying the analysis. We determine the complete set of Lorentz structures that can appear in the SCET Wilson coefficients and match onto them using results from a previous calculation. We run these coefficients from the scale M{sub {upsilon}} to the scale {lambda}{approx}1 GeV, thereby summing large logarithms. Finally we use our results to predict the ratio of branching fractions B({upsilon}{yields}{gamma}f{sub 2})/B(J/{psi}{yields}{gamma}f{sub 2}), B(J/{psi}{yields}{gamma}f{sub 2})/B({psi}{sup '}{yields}{gamma}f{sub 2}), and the partial rate for {upsilon}{yields}{gamma}{pi}{pi}.

• OSTI ID: 20708973
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 71; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

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