QUASIFREE PHOTOABSORPTION ON NEUTRON-PROTON PAIRS IN HE-3

摘要

Three-body photodisintegration of He-3 is calculated in the photon energy range 200-400 MeV assuming quasifree absorption on np pairs both in initial quasideuteron and singlet configurations. The model includes the normal nucleonic current, explicit meson exchange currents and the Delta(1232)-isobar excitation. The total cross section is increased by a factor of about 1.5 compared with free deuteron photodisintegration. Well below and above the Delta-region also some spin observables differ significantly from the ones of free deuteron disintegration due to the more compressed wave function of the correlated ip pairs in He-3 compared to the deuteron. The initial singlet state causes a significant change in the analysing power A(y). These differences could presumably be seen at the conjugate angles where two-body effects are maximized and where photoreactions could complement similar pion absorption experiments. [References: 40]