منابع مشابه
Anomalous Evolution of the Gottfried Sum
We discuss nonperturbative QCD evolution of nonsinglet nucleon structure functions, with particular application to the Gottfried sum. We show that the coupling of the quark partons to bound state mesons leads to nonperturbative contributions to the Altarelli– Parisi equations which, due to the axial anomaly, result in a strong scale dependence of nonsinglet structure functions for values of Q a...
متن کاملRe-evaluation of the Gottfried sum using neural networks
provides a determination of the light flavor asymmetry of the nucleon sea. The discovery by the NMC [1, 2, 3] that SG deviates from the simple quark model expectation SG = 1 3 has provided first evidence for an up-down asymmetry of the nucleon sea, a finding which has been subsequently confirmed in different contexts, is routinely included in modern parton fits, and has spawned a large theoreti...
متن کاملHadronic W production and the Gottfried sum rule.
The difference in production rate between W and W− at hadron colliders is very sensitive to the the difference between upand down-quark distributions in the proton. This sensitivity allows for a variety of useful measurements. We consider the difference ds(x,Q ) − us(x,Q2) in the sea distributions and the difference ∆u(x,Q2)−∆d(x,Q2) in the polarized parton distribution functions. In both cases...
متن کاملOn Reconciling Gottfried Sum Rule Violation with Cabibbo Theory†
We discuss the seemingly contradictory constraints of simultaneously preserving the SU(3)-symmetric Cabibbo description of the weak vector baryon matrix elements, accounting for SU(3) flavor symmetry breaking and describing the observed violation of the Gottfried Sum Rule. We try to construct a simple model that will satisfy these constraints and use it to explain the generic difficulties and t...
متن کاملNon - perturbative effect in the nucleon structure function and the Gottfried sum ∗
We investigate the non-perturbative effect in the nucleon structure function and the Gottfried sum by using a non-perturbative quark propagator with lowest dimensional condensate contributions from the QCD vacuum. It is shown that the non-perturbative effect modifies the conventional quarkparton model formula of the nucleon structure function at finite Q2 and suggests a non-trivial Q2 dependenc...
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ژورنال
عنوان ژورنال: Physical Review D
سال: 1994
ISSN: 0556-2821
DOI: 10.1103/physrevd.50.r1