Nuclear Modification of Transverse Momentum Dependent Parton Distribution Functions by a Global QCD Analysis.

ABSTRACT

We perform the first simultaneous global QCD extraction of the transverse momentum dependent (TMD) parton distribution functions and the TMD fragmentation functions in nuclei. We have considered the world set of data from semi-inclusive electron-nucleus deep inelastic scattering and Drell-Yan dilepton production. In total, this data set consists of 90 data points from HERMES, Fermilab, RHIC, and LHC. Working at next-to-leading order and next-to-next-to-leading logarithmic accuracy, we achieve a χ^{2}/d.o.f.=1.196. In this analysis, we perform the first extraction of nuclear modified TMDs and compare these to those in free nucleons. We also make predictions for the ongoing JLab 12 GeV program and future electron-ion collider measurements.