Dispersive study of light mesons
- José Ramón Peláez Sagredo Director
Defence university: Universidad Complutense de Madrid
Fecha de defensa: 18 October 2019
- Antonio Dobado González Chair
- Ángel Gómez Nicola Secretary
- Enrique Ruiz Arriola Committee member
- José Antonio Oller Berber Committee member
- Robert Kamisnki Committee member
Type: Thesis
Abstract
Quantum Chromodynamics (QCD) is the fundamental theory that explains the strong interactions between quarks and gluons. Unfortunately, the fact that QCD is asymptotically free at short distances produces the confinement of quarks at low energies, creating the well known hadrons, which are then appropriate the degrees of freedom to extract information from. In order to overcome this difficulty, Weinberg introduced in 1979 [1] Chiral Perturbation Theory (ChPT). This is an effective field theory that considers the octet of pseudo-goldstone bosons (pions, kaons and eta) produced by the chiral symmetry breaking as the degrees of freedom and provides a systematiclow-energy expansion for the observables. Nevertheless, ChPT is not able to determine with high accuracy the low energy parameters of the meson-meson interactions, besides, its series expansion does not respect unitarity, and hence can only be applied very close to threshold...