Nuclear andParticle Physics Colloquium76

(核與粒子物理學術報告會76)

Place:Room 513, Main Building, Beihang University

Title:Flavour and Strange Asymmetries of the Nucleon Sea inChiral Perturbation Theory.

Speaker:Mr. Pujiang Yusu

Abstract:

Motivated bythe NMC and NuTeV anomalies，we investigate theflavour and strange asymmetries of the Nucleon sea in the framework of ChiralPerturbation Theory. In phenomenological study, it was stated that physicalNucleon is surrounded by the Meson cloud which have contribution to the Nucleonstructure. In other words, quark distributions of Nucleon can be expressedterms of convolutions of the Meson-Baryon splitting functions and valancequark distributions of the intermediate Meson and Baryon states. Thesplitting functions can be calculated in the Chiral Perturbation Theory withdifferent regularization techniques, such as sharp cut-off, Pauli-Villars andnonlocal regularizations. Unlike the Pauli-Villars regularization, thenon-local regularization embedded in the nonlocalLagrangian in which the local field operator is replaced bythe nonlocal one and the gauge invariance is still satisfied. Inaddition, with nonlocal regularization, splitting functions only dependson only one cut-off parameter which will be fitted to the differentialcross section of baryon inclusive production. In the end, using this parameter,we numerically analyse the flavour and strange asymmetries of the Nucleonsea.

About speaker:

Mr.Pujiang Yusu is a Ph.D. student in IHEP, CAS and works on chiral perturbationtheory and its extensions and applications.