Probing the nucleon structure using Drell-Yan process at SeaQuest

SeaQuest is a fixed-target experiment at Fermilab using 120 GeV proton beam from the Main Injector. The experiment utilizes the Drell-Yan process to probe the anti-quark distributions inside the target nucleon. In particular, the Drell-Yan cross section ratios for liquid deuterium over hydrogen allows the measurement of sea quark asymmetry, d̅(x)/u̅(x), for x ranging from 0.13 to 0.45, extending the measurement of the previous experiment NuSea/E866 to larger x. The knowledge of the sea-quark asymmetry at large x is important for understanding the non-perturbative origin of the nucleon sea. Recent results on light sea-quark flavor asymmetry and its comparison with theoretical calculations and recent global PDFs will be presented in this talk. Additionally, SeaQuest experiment also provides the opportunity to study several physics topics. One example is the measurement of Drell-Yan differential cross sections, which allow improved constraints on magnitude and shape of sea-quark distributions. In particular, the p+d absolute cross section is sensitive to the d̅(x)+u̅(x) distribution at large x region. Another example is the measurement of charmonium production, which is sensitive to the gluon distributions. Current status of these analyses will also be reported.