Isovector part of optical potentials studied through analog transitions in the (p,n) reaction at 35 MeV

Quasielastic (p, n) reactions were studied at an incident proton energy of 35 MeV. Differential cross sections for isobaric analog ΔJπ=0⁺ (Fermi-type) transitions and their angular distributions were measured in 27 N > Z target nuclei ⁷Li, ⁹Be, ^13,14C, ¹⁵N, ⁵⁰Cr, ^54,56Fe, ^58,60,62,64Ni, ⁷⁰Zn, ⁷¹Ga, ⁹²Zr, ^{110,112,114,115}Cd, ^116,118,120Sn, ¹⁴⁰Ce, ^172,174,176Yb, and ²⁰⁸Pb. Pure ΔJπ=0⁺ Fermi-type transitions were observed in 23 of them. As for the four light odd-A nuclei, contributions from mixed ΔJπ≠0⁺ components were evaluated by microscopic distorted-wave Born approximation (DWBA) calculations to subtract them from the raw data and extract pure Fermi-type transition strengths. Thus 27 ΔJπ=0⁺ angular distributions were obtained, and fitted by macroscopic DWBA calculations with the Lane-model optical potential to derive systematically the isovector part of the potential. The best-fit parameters for each target are presented. The present results combined with our previous analysis on 13 other nuclei in the 17≤A≤48 region cover almost the entire mass region. They were used to obtain A-dependent global parameters by least-squares fit.