Four-nucleon transfer with the 32S( 16O, 12C) 36Ar reaction

Abstract

Angular distributions have been measured for the 32S( 16O, 12C) 36Ar reaction at 45.5 MeV leading to excited states between E x, = 0 and 8 MeV. Experimental cross sections are compared with exact finite-range DWBA calculations in combination with extensive shell-model calculations, which include sd- and fp-shell configurations. Transitions to low-energy positive-parity states and bound negative-parity states are well reproduced. The calculations, however, fail to describe some high-energy positive-parity states. Calculations with a complete cluster expansion for the four transferred nucleons give about 50% larger cross sections, but can not explain the observed discrepancies. Possible interference of reaction processes other than direct α-transfer and special structure effects are discussed.