Next Article in Journal
Tripartite Entanglement: Foundations and Applications
Next Article in Special Issue
Study of Very Forward Neutrons with the CMS Zero Degree Calorimeter
Previous Article in Journal
Driving Interactions Efficiently in a Composite Few-Body System
Previous Article in Special Issue
Open-Charm Hadron Measurements in Au+Au Collisions at √sNN = 200 GeV by the STAR Experiment
Open AccessArticle

Temperature Dependence of the Axion Mass in a Scenario Where the Restoration of Chiral Symmetry Drives the Restoration of the UA(1) Symmetry

1
Physics Department, Faculty of Science-PMF, University of Zagreb, Bijenička cesta 32, 10000 Zagreb, Croatia
2
Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia
*
Author to whom correspondence should be addressed.
Universe 2019, 5(10), 208; https://doi.org/10.3390/universe5100208
Received: 2 August 2019 / Revised: 30 September 2019 / Accepted: 1 October 2019 / Published: 8 October 2019
(This article belongs to the Special Issue The Zimányi School and Analytic Hydrodynamics in High Energy Physics)
The temperature (T) dependence of the axion mass is predicted for T s up to 2.3 × the chiral restoration temperature of QCD. The axion is related to the U A ( 1 ) anomaly. The squared axion mass m a ( T ) 2 is, modulo the presently undetermined scale of spontaneous breaking of Peccei–Quinn symmetry f a (squared), equal to QCD topological susceptibility χ ( T ) for all T. We obtain χ ( T ) by using quark condensates calculated in two effective Dyson–Schwinger models of nonperturbative QCD. They exhibit the correct chiral behavior, including the dynamical breaking of chiral symmetry and its restoration at high T. This is reflected in the U A ( 1 ) symmetry breaking and restoration through χ ( T ) . In our previous studies, such χ ( T ) yields the T-dependence of the U A ( 1 ) -anomaly-influenced masses of η and η mesons consistent with experiment. This in turn supports our prediction for the T-dependence of the axion mass. Another support is a rather good agreement with the pertinent lattice results. This agreement is not spoiled by our varying u and d quark mass parameters out of the isospin limit. View Full-Text
Keywords: axion; QCD; non-Abelian axial anomaly; UA(1) symmetry breaking; chiral restoration axion; QCD; non-Abelian axial anomaly; UA(1) symmetry breaking; chiral restoration
Show Figures

Figure 1

MDPI and ACS Style

Horvatić, D.; Kekez, D.; Klabučar, D. Temperature Dependence of the Axion Mass in a Scenario Where the Restoration of Chiral Symmetry Drives the Restoration of the UA(1) Symmetry. Universe 2019, 5, 208.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop