π-NUCLEAR DOUBLE CHARGE EXCHANGE REACTION AND NUCLEAR STRUCTURE

Abstract: Using coherent fluctuation nuclear model and Glauber's multiple scattering theory,the double charge exchange (DCE) reaction cross sections for π⁺ on ¹⁶O and on ¹⁶O are calculated. The results show that, owing to the paring effect, the probability of the double nucleon transition between the isospin non-analogue states increases remarkably: the calculated values of the ratio of a σ ¹⁸O (π⁺, π^-) ¹⁸Ne_g.s. to σ (¹⁶O (π⁺,π^-) ¹⁶Ne)_g.s. fit the experimental data quite well. It also shows that, for fitting the experimental data, the magnitude of the 2p-2h configuration components exsited in ¹⁶O ground state would not be too large. The effect of the intermediate states in multiple stage processes is estimated, which shows that the contribution of these processes to the DCE reaction is rather small.