The Time-Reversal- and Parity-Violating Nuclear Potential in Chiral Effective Theory
- Publication date
- 2011
- Publisher
Abstract
We derive the parity- and time-reversal-violating nuclear interactions stemming from the QCD ¯
term and quark/gluon operators of effective dimension 6: quark electric dipole moments, quark and
gluon chromo-electric dipole moments, and two four-quark operators. We work in the framework
of two-flavor chiral perturbation theory, where a systematic expansion is possible. The different
chiral-transformation properties of the sources of time-reversal violation lead to different hadronic
interactions. For all sources considered the leading-order potential involves known one-pion exchange,
but its specific form and the relative importance of short-range interactions depend on the source.
For the ¯ term, the leading potential is solely given by one-pion exchange, which does not contribute
to the deuteron electric dipole moment. In subleading order, a new two-pion-exchange potential
is obtained. Its short-range component is indistinguishable from one of two undetermined contact
interactions that appear at the same order and represent effects of heavier mesons and other short-
range QCD dynamics. One-pion-exchange corrections at this order are discussed as well.