$\eta$-${\eta }^{\prime }$ mixing in large-$N_c$ chiral perturbation theory: discussion, phenomenology, and prospects

Abstract

A systematic study of the $\eta$-${\eta }^{\prime }$ mixing in Large-$N_c$ chiral perturbation theory is presented with special emphasis on the role of the next-to-next-to-leading-order contributions in the combined momentum, quark-mass, and $1/N_c$ expansions. At this order, loop corrections as well as OZI-rule-violating pieces need to be included. Mixing angles as well as pseudoscalar decay constants are discussed within this framework. The results are compared with recent phenomenological approaches.

Comments: 10 pages, 3 figures, talk presented by P. Masjuan at the 8th International Workshop on Chiral Dynamics, 29 June 2015 - 3 July 2015, Pisa, Italy