XXVIII International Workshop on Deep Inelastic Scattering and Related Subjects

The shape of the d¯−u¯ asymmetry from DIS and Drell-Yan data

24 Mar 2020, 17:00

15m

Brooklyn, NY

Contributed Talk Structure Functions and Parton Densities Structure function and parton densities

Speaker

Wally Melnitchouk (Jefferson Lab)

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 $\overline{d}-\overline{u}$ 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 $\overline{d}>\overline{u}$ for all values of $x$ currently accessible. We compare the shape of the fitted $\overline{d}-\overline{u}$ 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 $x$.