Studies On The Proton-proton Momentum Correlation Function And The Mechanism Of Two-proton Emission For Proton-rich Nuclei

The effect of source size and emission time on the proton-proton?p-p?momentum correlation function was studied systematically.Assuming a sphere Gaussian source with space and time profile according to the function S?r,t?^exp?-r²/2r₀²-t/??in the correlation function calculation code?CRAB?,the results indicate that one C_pp?q?distribution corresponds to only unique source size r₀ and emission time?.Considering the possible nuclear deformation from a sphere,the ellipsoid Gaussian source characterized by the deformation parameter?=?R/R was simulated.There is almost no difference of C_pp?q?between the results of sphere and ellipsoid shape sources.These results indicate that unique source size r₀ and emission time?could be extracted from the p-p momentum correlation function which is important for identifying the mechanism of two-proton emission from proton-rich nuclei.Furthermore,considering the possible existance of cluster structure in a nucleus,the double Gaussian source was used and the results show there is an evident peak at r₀=1.5 fm in the difference of maximum C_pp?q?between sphere Gaussian source and double Gaussian source.This may give a possible solution for experimentally identifying the cluster structure of proton-rich nuclei.