Unpolarized transverse momentum dependent sea quark asymmetries of light nuclei in nonperturbative QCD

Abstract

We investigate the transverse momentum dependence of sea quark asymmetries in Helium and deuteron nuclei. To this end, we calculate the nuclear sea quark distributions, in first step, based on the modified chiral quark exchange formalism at low $Q^2$ scale ($Q^2=0.35~GeV^2$) in nonperturbative region of quantum chromodynamics (QCD). In this formalism the sea quark distributions are not symmetric because of chiral symmetry breaking. In next step, we compute transverse momentum dependence of sea quark distributions using the covariant parton model (CPM) in which the unpolarized transverse momentum dependent (TMD) quark distribution functions are related to corresponding integrated ones. Finally, we obtain TMD quark-anti quark asymmetry of strange sea for $^3He$ and deuteron and also $(\bar{d}-\bar{u})$ asymmetry for $^3He$. In order to study the EMC effect in $^3He$ nucleus, we determine the ratio of TMD strange sea asymmetries of $^3He$ and deuteron.