Off-shell partons; consequences for Gottfried Sum Rule, Drell-Yan process and J/{psi} production

Journal Article · Fri Oct 01 04:00:00 EDT 1993 · Bulletin of the American Physical Society

OSTI ID:387162

Sawicki, M; Vary, J P

We discussed the violation of Gottfried Sum Rule (GSR) reported in DIS by the NMC at CERN, and depletion of the yields of massive muon pairs at large values of Feynman {chi}{sub F} observed in collsions of 800-GeV/c protons with nuclei in Fermilab experiment E772. We point out that there is a quite simple possibility to account for a significant part of these experimental findings. In light front picture of DIS one replaces the parton model restriction {kappa}{sub {alpha}} = {chi}{sub Bj}P{sub {mu}} by rigorous parametrization {kappa}{sup +} = {chi}P{sup +}. Consequently the struck parton is found to be spacelike for the values of x in the vicinity of end points of the interval [0,1] and {chi} {ne} {chi}{sub Bj}. This introduces significant corrections to the GSR. For the dimuon depletion observed in E772 similar argument points to a mechanism involving only the target distributions: while value of (light front) variable {chi} of a parton in isolated single nucleon already differs from parton model result, the value {chi} of a sea parton actually probed in nuclear target is slightly shifted with respect to that probed in nucleon target. This indicates that the parton in nucleus is slightly more spacelike or/and its perpendicular momentum is slightly reduced.

• OSTI ID: 387162
• Report Number(s): CONF-931044--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 9 Vol. 38; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
J PSI-3097 MESONS
MUON PAIRS
PARTICLE PRODUCTION
PARTON MODEL
SUM RULES