Large-N(c) limit reduces the number of independent few-body parity-violating low-energy constants in pionless effective field theory

Abstract

The symmetries of the Standard Model dictate that for very low energies, where nucleon dynamics can be described in terms of a pionless effective field theory, the leading-order parity-violating nucleon-nucleon Lagrangian contains five independent unknown low-energy constants (LECs). We find that imposing the approximate symmetry of QCD that appears when the number of colors N(c) becomes large reduces the number of independent LECs to two at leading order in the combined pionless effective field theory and large-N(c) expansions. We also find a relation between the two isoscalar LECs in the large-N(c) limit. This has important implications for the number of experiments and/or lattice calculations necessary to confirm this description of physics.