We compute the third-order correction to electromagnetic S-wave quarkonium production and annihilation rates due to the emission and absorption of an ultrasoft gluon. Our result completes the analysis of the non-relativistic quarkonium bound-state dynamics in the next-to-next-to-next-to-leading order. The impact of the ultrasoft correction on the ϒ(1S) leptonic width and the top quark–antiquark threshold production cross section is estimated.
No takes yet. Share an insight, caveat, or question.
Beneke et al. (2007) studied this question.
Synapse has enriched 5 related papers. Consider them for comparative context: