Center for Theoretical Physics of the Universe (CTPU)

Poincare invariance in low-energy EFTs for QCD and its implications to long-distance QCD potentials via effective string theory

by Sungmin Hwang

Wednesday, 16 November 2016 from to (Asia/Seoul)
We use nonlinear field transformations for non-relativistic fields to implement Poincare invariance in Non-Relativistic QCD (NRQCD) and potential Non-Relativistic QCD (pNRQCD)​, and show how the Poincare algebra is satisfied for these transformations, which thereby gives complementary information on the Wilson coefficients. Upon the established constraints on the Wilson coefficients, which are potentials terms especially in pNRQCD, we explore their analytic expressions for the physical system at the long distance separation between a heavy quark and a heavy antiquark, via the framework of the effective string theory (EST), whose dynamical degrees of freedom are the transversal vibration modes of a string connecting the quark and antiquark. Finally, we discuss how the (dimensionful) parameters that arise from the EST are reduced/simplified by using the Poincare invariance in pNRQCD and NRQCD.