A study of 0° transverse polarization transfer in (p, n) reactions from ¹²C, ¹³C and ⁴⁰Ca at 80 and 50 MeV

Transverse-polarization-transfer coefficients D_NN for the (p, n) reaction at θ = 0° have been measured on ¹²C, ¹³C and ⁴⁰Ca targets at E_p = 80 MeV and the ¹²C and ¹³C targets at E_p = 50 MeV. As for the ¹²C and ¹³C(p, n) reactions, D_NN for the transitions corresponding to the Gamow-Teller type and the Fermi and Gamow-Teller mixed type are compared to distorted-wave Born-approximation calculations. Observed D_NN values are reproduced reasonably well by the calculations employing either the effective interactions M3Y or the M3Ym in which V_Tτ and V_στ are modified. A value for R² = [σ_GT(0°)/σ_F(0°)][B(F)/B(GT)] is deduced by using only the D_NN data from the ¹³C(p, n) reaction, and is roughly consistent with R = 1 55E_p, empirically determined from the cross-section data at 0°. As for the ⁴⁰Ca(p, n) reaction, the observed value for the giant-dipole-resonance region is D_NN = 0.23±0.05, indicating that the spinflip and non-spinflip resonances are unresolved. Utilizing information from higher-energy D_NN data, the transition-strength ratio f of non-spinflip to spinflip and D_NN(SF) pertinent to spinfli[ transitions have been deduced empirically for the giant-dipole-resonance region. Obtained f and D_NN(SF) values are 1.4±0.4 and -0.25±0.10, respectively, and are roughly consistent with the RPA calculations.