PUB - Publikationen an der Universität Bielefeld

Quark number susceptibility on the lattice, obtained by merely adding a $\muN$ term with $\mu$ as the chemical potential and $N$ as the conserved quarknumber, has a quadratic divergence in the cut-off $a$. We show that it issimply a faithful representation of the corresponding continuum result. Whileone can eliminate it in the free theory by suitably modifying the action, as ispopularly done, it can simply be subtracted off as well. Computations of higherorder susceptibilities, needed for estimating the location of the QCD criticalpoint, then need a lot fewer number of quark propagators at any order. We showthat in the interacting theory this method of divergence removal works.