The radiative decay Y→Xγ was first investigated about a quarter century ago. The conventional wisdom was that this process was computable in perturbative QCD due to the large b mass. The current method for calculating the direct radiative decay of the γ was by using the operator product expansion (OPE), with the operators scaling as some power of the relative velocity of the heavy quarks, given by the power counting of nonrelativistic QCD (NRQCD).
|Physical review letters
|Published - Jan 24 2003
ASJC Scopus subject areas
- General Physics and Astronomy