Photodisintegration reactions of 3He and 4He at TAGX

Abstract

The measurement of the photodisintegration cross sections for few-nucleon systems, such as 3He and 4He, has been an important experimental program of the TAGX project. This program aimed at investigating reaction mechanisms of the nuclear photodisintegration in the intermediate photon energy (Eγ ≥ 100 MeV). In a series of this TAGX program, the measurements of the photodisintegration reaction cross section for 3He and 4He covering a wide kinematical region have been attempted in a kinematically complete way, which enabled the exploration of the reaction mechanisms in detail. The dominant reaction mechanism is revealed to be photon absorption by two nucleons (2N) in a nucleus. In the TAGX program, different photon absorption modes contributing the photodisintegration processes are separately identified. Success has been achieved in extracting the 2N cross section over a wide Eγ range for the first time. By comparing the 2N cross sections with microscopic theories, one can study the two nucleon system in a nucleus.