TY  - JOUR
AU  - Lu, Zhen-Yan
AU  - Du, Meng-Lin
AU  - Guo, Feng-Kun
AU  - Meißner, Ulf-G.
AU  - Vonk, Thomas
TI  - QCD θ-vacuum energy and axion properties
JO  - Journal of high energy physics
VL  - 2020
IS  - 5
SN  - 1029-8479
CY  - [Trieste]
PB  - SISSA
M1  - FZJ-2021-00159
SP  - 1
PY  - 2020
AB  - At low energies, the strong interaction is governed by the Goldstone bosons associated with the spontaneous chiral symmetry breaking, which can be systematically described by chiral perturbation theory. In this paper, we apply this theory to study the θ-vacuum energy density and hence the QCD axion potential up to next-to-leading order with N non-degenerate quark masses. By setting N = 3, we then derive the axion mass, self-coupling, topological susceptibility and the normalized fourth cumulant both analytically and numerically, taking the strong isospin breaking effects into account. In addition, the model-independent part of the axion-photon coupling, which is important for axion search experiments, is also extracted from the chiral Lagrangian supplemented with the anomalous terms up to O(p6).
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000532132800001
DO  - DOI:10.1007/JHEP05(2020)001
UR  - https://juser.fz-juelich.de/record/889254
ER  -