1. Dynamical model for the ABC effect
- Author
-
D. Levy, A. Santoro, and J.C. Anjos
- Subjects
Physics ,Nuclear and High Energy Physics ,Low energy ,Angular distribution ,Amplitude ,Deuterium ,Helium-3 ,Mass spectrum ,Atomic physics ,Nucleon ,Fermi Gamma-ray Space Telescope - Abstract
A model for ABC production is presented, which is experimentally observed in the missing mass spectrum of the reaction dp yields /sup 3/He + (MM)/ sup 0/. The reaction is assumed to be split in two successive steps, namely: (i) N/sub 1/p yields d/sub i/ pi /sub 1/ followed by (ii) N/sub 2/d/ sub i/ yields /sup 3/He pi /sub 2/, N/sub 1/ and N/sub 2/ being the two nucleons of the incident deuteron and d/sub i/ an intermediate deuteron. The total amplitude is factorized into the product of the two amplitudes of reactions (i) and (ii). It is known that at low energy these two reactions are dominated by DELTA production. This implies that the total cross sections are given by Breit-Wigner type formulae and that the angular distributions are peaked in the backward and forward directions. The two main results are: (i) at given incident energy, the ABC effect results from the angular distribution of the two intermediate reactions; (ii) the energy dependence of the ABC is deduced from those of the intermediate processes. The resulting fits are generally excellent when the Fermi motion in the initial deuteron is taken into account.
- Published
- 1973