2024/10/29 by Ulf-G. Meißner, Meißner, Ulf-G.
Chemistry · Engineering · #FOS: Physical sciences #Field-Flow Fractionation Techniques #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #High Energy Physics - Theory (hep-th) #Molecular Spectroscopy and Structure #Nuclear Experiment (nucl-ex) #Nuclear Theory (nucl-th) #Phase Equilibria and Thermodynamics
paper · pdf · doi:10.48550/arxiv.2410.21912
openalex publication_date 2024/10/29 · openalex created_date 2024/11/14 · openalex updated_date 2026/07/31
In the limit of vanishing up, down and strange quark masses, QCD exhibits a chiral symmetry. This symmetry is broken spontaneously to its vector subgroup, giving rise to Goldstone bosons. These acquire a small mass through the explicit chiral symmetry breaking for non-vanishing quark masses. The consequences of these broken symmetries can be investigated in a suitably tailored effective field theory called chiral pertubation theory. It admits a perturbative expansion in the external momenta and the Goldstone boson masses and can be systematically analyzed in terms of a loop expansion. The appearing ultraviolet divergences in loop diagrams can be dealt with order-by-order through the Goldstone boson contact interactions. Matter fields like the lowest-lying baryons can also included, leading to a rich and testable phenomenology of low-energy QCD.