Speaker
Description
Using data from a recent reanalysis of neutron structure functions extracted from inclusive proton and deuteron DIS, we re-examine the constraints on the shape of the $\bar d − \bar u$ asymmetry in the proton at large parton momentum fractions $x$. A global analysis of the proton–neutron structure function difference from BCDMS, NMC, SLAC and Jefferson Lab DIS measurements, and of Fermilab Drell-Yan lepton-pair production cross sections, suggests that existing data can be well described with $\bar d > \bar u$ for all values of $x$ currently accessible. We compare the shape of the fitted $\bar d − \bar u$ distributions with expectations from nonperturbative models based on chiral symmetry breaking, and assess the impact of new data from the SeaQuest experiment at larger values of $x$.
