Quenched Chiral Perturbation Theory to one loop

We calculate the divergences of the generating functional of quenched Chiral Perturbation Theory at one loop, and renormalize the theory by an appropriate definition of the counterterms. We show that the quenched chiral logarithms can be accounted for by defining a renormalized B0 parameter which, at lowest order, is proportional to the vacuum expectation value of the scalar quark density. Finally, we calculate several quantities at one loop to better analyze the modifications induced by quenching in the ultraviolet finite part of the one–loop corrections. We point out that some of the finite loop corrections may diverge in the chiral limit. PACS: 12.39.Fe, 12.38.Gc.