Speaker
Samuel F. Romera
(University of the Basque Country)
Description
When quarkonium is produced in the low-transverse momentum region, the contribution of soft and ultra-soft radiation between the heavy-quark pair becomes relevant. At this region, non-relativistic QCD (NRQCD) breaks down and we need to promote the long-distance matrix elements to the TMD shape functions (TMDShFs) in the NRQCD factorization procedure. In this talk, I discuss the cross section factorization for the J/ψ leptoproduction in terms of these TMDShFs at small transverse momentum.
I then discuss our results of the TMDShFs at next-to-leading order in the QCD coupling constant, the renormalization group evolution for the TMDShFs and the matching onto the collinear functions at high transverse momentum.
Primary author
Samuel F. Romera
(University of the Basque Country)
Co-authors
Miguel Echevarria
(University of the Basque Country UPV/EHU)
Pieter Taels
(University of Antwerp)
