Radiative Upsilon Decay at the Endpoint

  • Adam K. Leibovicha


The standard NRQCD power counting breaks down and the OPE gives rise to color-octet shape functions at the upper endpoint of the photon energy spectrum in radiative Υ decay. Also in this kinematic regime, large Sudakov logarithms appear in the octet Wilson coefficients, ruining the perturbative expansion. Using SCET, the octet shape functions arise… (More)


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