The ratio of cross-sections for muon pair production through the Drell-Yan process in p - p and p - d reactions has been measured at y ~ 0, with 450 GeVc incident protons. The asymmetry ADY = δpp - δpn/δpp+δpn amounts to -0.09 +/- 0.02 +/- 0.025. The ratio u/d of the nucleon sea structure functions derived from this measurement amounts to 0.51 +/- 0.04 +/- 0.05 at x = 0.18 and suggests that isospin symmetry is broken in the light quark sea of the nucleon.
Study of the isospin symmetry breaking the in the light quark sea of the nucleon from the Drell-Yan process
CHIAVASSA, Emilio Luciano;GALLIO, Mauro;MASERA, Massimo;VERCELLIN, Ermanno;
1994-01-01
Abstract
The ratio of cross-sections for muon pair production through the Drell-Yan process in p - p and p - d reactions has been measured at y ~ 0, with 450 GeVc incident protons. The asymmetry ADY = δpp - δpn/δpp+δpn amounts to -0.09 +/- 0.02 +/- 0.025. The ratio u/d of the nucleon sea structure functions derived from this measurement amounts to 0.51 +/- 0.04 +/- 0.05 at x = 0.18 and suggests that isospin symmetry is broken in the light quark sea of the nucleon.File in questo prodotto:
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