Strong CP Violation and large-$N_c$ spin-flavor symmetry

Abstract

We revisit the contribution of the QCD $\bar{\theta }$ term to the CP violating pion-nucleon couplings and the nucleon electric dipole moment in a combined large-$N_c$ and chiral perturbation theory framework. In particular, we approach this issue through the emergent spin-flavor symmetry of the baryon sector at large but finite $N_c$. We obtain good agreement with previous analyses for the pion-nucleon couplings and show that the large-$N_c$ framework indicates that tree-level contributions to the electric dipole moment possibly play a dominant role. The spin-flavor symmetry also enables us to provide novel constraints on CP violating pion-$\Delta$ couplings as well as the $\Delta$ electric dipole moment and $\Delta N$ transition moment.

9 pages, version published in Phys. Rev. D

References in corpus (14)

• Measurement of the permanent electric dipole moment of the neutron
• FLAG Review 2021
• Ab initio calculation of the neutron-proton mass difference
• Electromagnetic mass splittings of the low lying hadrons and quark masses from 2+1 flavor lattice QCD+QED
• Strong-Isospin Violation in the Neutron-Proton Mass Difference from Fully-Dynamical Lattice QCD and PQQCD
• Reevaluation of Neutron Electric Dipole Moment with QCD Sum Rules
• The Electric Dipole Form Factor of the Nucleon in Chiral Perturbation Theory to Sub-leading Order
• The electric dipole moment of the deuteron from the QCD $\theta$-term
• Neutron electric dipole moment using lattice QCD simulations at the physical point
• Contribution of the QCD $\Theta$-term to nucleon electric dipole moment
• Theta dependence in Holographic QCD
• The Electric Dipole Moment of the Nucleons in Holographic QCD
• Neutron electric dipole moment from gauge/string duality
• Lattice QCD and the Neutron Electric Dipole Moment

Cited by in corpus (1)

• Nucleon Electric Dipole Moments in Paramagnetic Molecules through Effective Field Theory