We study the isovector weak response of the core to an external perturbation using linear response theory in nuclear matter. We extend previous results to the kinematic region away from the long wavelength regime where the effects have been proven small. For the muon capture process we found a sizable quenching of the contribution of the induced pseudoscalar term. Applied to actual nuclei, however, the strong density dependence of the weak isovector response washes out the screening found at nuclear matter densities, slightly modifying muon capture rates.

• Received 1 September 1993

DOI:https://doi.org/10.1103/PhysRevC.49.2005