On curing the divergences in the quark number susceptibility

Abstract

Adding chemical potential $\mu$ linearly as $\mu N$ to the lattice QCD action, where $N$ is a conserved quark/baryon number, leads to a quadratic divergence as $a^{-2}$. We argue that it is inherited from the continuum theory and can be subtracted off on the lattice following a similar manner in the continuum. We test this idea for quenched quark number susceptibilities and demonstrate a finite continuum limit numerically.