Analyzing Powers for (p, t) Transitions to the First-Excited 2⁺ States of Medium-Mass Nuclei and Nuclear Collective Motion

Abstract

Vector analyzing powers A(θ) and differential cross sections σ(θ) have been measured by use of a polarized proton beam of 22.0 MeV for (p, t) reactions leading to the first-excited 2⁺ (2₁⁺) states of the eighteen nuclei of N=50–82: ^92,94,96Mo, ^98,100,102Ru, ^{102,104,106,108}Pd, ^110,112,114Cd, ¹¹⁶Sn, ^120,126,128Te and ¹³⁶Ba. In addition A(θ) and σ(θ) for ^104,110Pd(p, t) ^102,108Pd(0_g⁺, 2₁⁺) have been measured at E_p=52.2 MeV. The results are analyzed in terms of the first- and second-order DWBA including both inelastic two-step and sequential transfer (p, d)(d, t) two-step processes. Interference between the direct and the two-step processes is important. The nuclear-structure wave functions are constructed under the boson expansion method and the quasiparticle random phase approximation method.