Cancellation of Sudakov Logarithms in Radiative Decays of Quarkonia

Abstract

We study infrared QCD effects in radiative quarkonia decays. We examine the endpoint region z -> 1 of the photon spectrum. We point out a cancellation mechanism for the corrections in ${\alpha }_s^n{\ln }^m(1-z)$, $m\le 2n$, in the short-distance coefficient for the color-singlet Fock state in the quarkonium. The cancellation is due to the coherence of the color radiation, and applies even though logarithmic contributions are present in the jet distributions associated with the decay. We comment on the implications of our results for the modeling of hadronization in the endpoint region and for the role of color-octet states in the quarkonium.

15 pages, 1 figure

References in corpus (2)

• Determination of the QCD Coupling ${\alpha }_s$
• The QCD Coupling Constant

Cited by in corpus (9)

• Transverse momentum dependent gluon density from DIS precision data
• Forward Z-boson production and the unintegrated sea quark density
• Resumming the color-octet contribution to radiative Upsilon decay
• The Photon Spectrum in Upsilon Decays
• Flavor-singlet light-cone amplitudes and radiative Upsilon decays in SCET
• Semi-inclusive radiative decays of Upsilon 1S
• Soft, collinear and non-relativistic modes in radiative decays of very heavy quarkonium
• Radiative Upsilon Decay at the Endpoint
• Color coherence in multi-jet final states