(CNS + Radiation Lab. Seminar)
The partonic structure of the proton is one of the most vital topics in the present hadron physics. Particularly the distribution of antiquarks is of great interest because it has unique sensitivity to the dynamics of the strong force (i.e. QCD) which constructs the proton. SeaQuest at Fermilab is a fixed-target experiment to measure the Drell-Yan process in p+p and p+d, using the 120-GeV proton beam and targets of liquid hydrogen and liquid deuterium. It aims at precisely measuring the flavor asymmetry of light-antiquark distributions (anti-down(x)/anti-up(x)) at large x in the proton. During the course of operations, completed in July 2017, it recorded data from 1.4*10^18 protons on various targets. In this seminar, the physics motivation and the latest status of the measurement will be presented.
Ken Yako, Satoshi Yokkaichi