Different perspectives to axion quality problem.
by
Online
KIAS
Title: Different perspectives to axion quality problem.
Speaker: Gongjun Choi (CERN)
Abstract: In spite of its capability to explain the CP invariance of the QCD sector, QCD axion suffers from the quality issue as there can be contributions to the axion potential other than the QCD instanton. Particularly the global nature of the PQ symmetry poses challenges to the high quality of QCD axion. In this talk, I will discuss two different ways to handle the quality issue: (1) suppressing dangerous higher dimensional operators with the aid of symmetries other than PQ. As an example, I will discuss the use of symmetries well-motivated by other issues in BSM physics (B-L, SUSY, R-symmetry). (2) gauging axionic shift symmetry based on the dual formulation of QCD axion. I will comment on an implication of the dual description.
