Analyzing Powers for (<i>p</i>,<i>t</i>) 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 + (2 1 + ) states of the eighteen nuclei of N =50–82: 92,94,96 Mo, 98,100,102 Ru, 102,104,106,108 Pd, 110,112,114 Cd, 116 Sn, 120,126,128 Te and 136 Ba. In addition A (θ) and σ(θ) for 104,110 Pd( p , t ) 102,108 Pd(0 g + , 2 1 + ) 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.