MODIFICATIONS OF THE TENSOR AND SPIN-ORBIT INTERACTIONS AND THE STRETCHED STATES IN PB-208

We have reanalyzed the (e,e') and (p,p') data at 318 MeV on the stretched, 12(1,2)- and 14-, states of Pb-208 using the ideas of G. Brown and co-workers on the reduction of meson and nucleon masses in the nuclear medium. The reaction calculations are compared with new, large basis random-phase-approximation calculations using a residual interaction, also modified, in a consistent way. The resulting interaction, based on the one boson exchange (pi + rho) model, has reduced tensor and enhanced spin-orbit strengths. Agreement between electron and proton quenching factors is found for effective masses, m* /m congruent-to 0.79 - 0.86. The reduction or enhancement factors for the modified interaction are in qualitative agreement with those found in other analyses.