Endpoint Logarithms in e+e- -> J/psi + eta_c

2013/01/16 by Geoffrey T. Bodwin, Bodwin, Geoffrey T., Hee Sok Chung +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph

paper · pdf · doi:10.48550/arxiv.1301.3937

9 pages, 1 figure, talk given by Hee Sok Chung at Xth Quark Confinement and the Hadron Spectrum, 8-12 October 2012, TUM Campus Garching, Munich, Germany

arxiv created 2013/01/16 · arxiv updated 2013/01/21

Abstract

We investigate the origin of the double logarithms of Q²/m_c² that appear in the calculation of the cross section for e+e- -> J/psi + eta_c at next-to-leading order in alpha_s. We find that, diagram-by-diagram, the double logarithms are accounted for by Sudakov double logarithms and endpoint double logarithms. The Sudakov double logarithms cancel in the sum over all diagrams, but the endpoint double logarithms do not. We reinterpret the endpoint double logarithms in terms of a leading region of loop integration in which a spectator fermion line becomes soft. This reinterpretation may simplify the process of establishing an all-orders factorization theorem for this helicity-flip process, which, in turn, might allow one to resum logarithms of Q²/m_c² to all orders in alpha_s.

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