Nuclear and Particle Physics Colloquium
Place:Room 513, Main Building, Beihang University
Time:11:00-12:00,April 1st, 2019
Title:Flavour and Strange Asymmetries of the Nucleon Sea in Chiral Perturbation Theory.
Speaker:Mr. Pujiang Yusu
Motivated by the NMC and NuTeV anomalies，we investigate the flavour and strange asymmetries of the Nucleon sea in the framework of Chiral Perturbation Theory. In phenomenological study, it was stated that physical Nucleon is surrounded by the Meson cloud which have contribution to the Nucleon structure. In other words, quark distributions of Nucleon can be expressed terms of convolutions of the Meson-Baryon splitting functions and valance quark distributions of the intermediate Meson and Baryon states. The splitting functions can be calculated in the Chiral Perturbation Theory with different regularization techniques, such as sharp cut-off, Pauli-Villars and nonlocal regularizations. Unlike the Pauli-Villars regularization, the non-local regularization embedded in the nonlocal Lagrangian in which the local field operator is replaced by the nonlocal one and the gauge invariance is still satisfied. In addition, with nonlocal regularization, splitting functions only depends on only one cut-off parameter which will be fitted to the differential cross section of baryon inclusive production. In the end, using this parameter, we numerically analyse the flavour and strange asymmetries of the Nucleon sea.
Mr. Pujiang Yusu isa Ph.D.studentin IHEP, CAS and works on chiral perturbation theory and its extensions and applications.