%0 Conference Paper
%A Wirzba, Andreas
%T Strong CP Problem
%V Regio2021
%I Sissa Medialab Trieste, Italy
%M FZJ-2022-06042
%P 003-026
%D 2022
%< Proceedings of RDP online PhD school and workshop 'Aspects of Symmetry' — PoS(Regio2021) - Sissa Medialab Trieste, Italy, 2022. - ISBN - doi:10.22323/1.412.0003
%X Quantum chromodynamics, the theory of strong interaction, admits a term which explicitly violates parity P and time reflection invariance T and due to the CPT theorem, also CP. Naturalness would predict this term with strength one, whereas empirical evidence from the electric dipole moment of the neutron yields an upper bound of almost vanishing strength of this term. This is the so-called strong CP problem. In this report, I follow the path from the initial U(1)A problem of strong interaction physics, via the U(1)A anomaly and instantons, the theta vacuum, the electric dipole moment of the neutron and the necessity of explicit symmetry breaking to the Peccei-Quinn model, extended to invisible axions and axion-like particles and finally back to electric dipole moments of subatomic particles.
%B RDP online PhD school and workshop 'Aspects of Symmetry'
%C 8 Nov 2021 - 12 Nov 2021, Online (Rep of Georgia)
Y2 8 Nov 2021 - 12 Nov 2021
M2 Online, Rep of Georgia
%F PUB:(DE-HGF)8 ; PUB:(DE-HGF)7
%9 Contribution to a conference proceedingsContribution to a book
%R 10.22323/1.412.0003
%U https://juser.fz-juelich.de/record/916241