Speaker
Description
The partonic structure of the proton is of great interest in hadron physics. Particularly the distribution of antiquarks has gained a lot of attention due to its unique sensitivity to the dynamics of the strong force (i.e. QCD).
SeaQuest at Fermilab is a fixed-target experiment to measure the Drell-Yan process in proton+proton and proton+deuteron scattering, using the 120-GeV proton beam and targets of LH2, LD2, C, Fe and W. SeaQuest's primary goal is to precisely measure the flavor asymmetry of the light-antiquark distributions ($\bar{d}(x)/\bar{u}(x)$) at large x. SeaQuest also measures nuclear effects on anti-quarks and the partonic energy loss in cold nuclear matter. It completed the data taking in 2017. The latest results will be discussed in this talk, with emphasis on the $\bar{d}(x)/\bar{u}(x)$ result that was published in February 2021.
SpinQuest is a successor to SeaQuest, using transversely-polarized NH$_3$ and ND$_3$ targets. SpinQuest aims to directly measure the Sivers asymmetry of light antiquarks via the Drell-Yan process. It is now completing construction of the experimental apparatus, and plans to start taking data in spring 2021. The status and the prospects of the experiment will be presented in this talk.
