Baryon mass splittings and strong CP violation in SU(3) Chiral Perturbation Theory

Jun 20, 2015
29 pages
Published in:
  • Phys.Rev.C 92 (2015) 4, 045201
  • Published: Oct 8, 2015
e-Print:
Report number:
  • LA-UR-15-23860,
  • NT@WM-15-07,
  • JLAB-THY-15-2061

Citations per year

20152018202120242025051015
Abstract: (APS)
We study SU(3) flavor-breaking corrections to the relation between the octet baryon masses and the nucleon-meson CP-violating interactions induced by the QCD θ¯ term. We work within the framework of SU(3) chiral perturbation theory and work through next-to-next-to-leading order in the SU(3) chiral expansion, which is O(mq2). At lowest order, the CP-odd couplings induced by the QCD θ¯ term are determined by mass splittings of the baryon octet, the classic result of Crewther et al. [Phys. Lett. B 88, 123 (1979)PYLBAJ0370-269310.1016/0370-2693(79)90128-X]. We show that for each isospin-invariant CP-violating nucleon-meson interaction there exists one relation that is respected by loop corrections up to the order we work, while other leading-order relations are violated. With these relations we extract a precise value of the pion-nucleon coupling g¯0 by using recent lattice QCD evaluations of the proton-neutron mass splitting. In addition, we derive semiprecise values for CP-violating coupling constants between heavier mesons and nucleons with ∼30% uncertainty and discuss their phenomenological impact on electric dipole moments of nucleons and nuclei.
Note:
  • 49 pages. Published version
  • 12.39.Fe
  • 11.30.Er
  • 13.75.Gx
  • 14.20.-c
  • CP: violation
  • baryon: mass difference
  • perturbation theory: chiral
  • baryon: octet
  • p n: mass difference
  • expansion: chiral
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