Abstract
A precise measurement of the ratio of Drell-Yan yields from an 800GeV/c proton beam incident on hydrogen and deuterium targets is reported. Over 140 000 Drell-Yan muon pairs with dimuon mass Mμ+μ−≥4.5GeV/c2 were recorded. From these data, the ratio of antidown ( d¯) to antiup ( u¯) quark distributions in the proton sea is determined over a wide range in Bjorken x. A strong x dependence is observed in the ratio d¯/u¯, showing substantial enhancement of d¯ with respect to u¯ for x<0.2. This result is in fair agreement with recent parton distribution parametrizations of the sea. For x>0.2, the observed d¯/u¯ ratio is much nearer unity than given by the parametrizations.Received 9 December 1997DOI:https://doi.org/10.1103/PhysRevLett.80.3715©1998 American Physical Society
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
