Statistical analysis of correlated resonance phenomena in two systems: 28Si+20Ne and 24Mg+20Ne.

Abstract

A differentially pumped windowless {sup 20}Ne gas target was used to measure angle averaged excitation functions for binary decay of the {sup 28}Si+{sup 20}Ne reaction into low-lying states of {sup 28}Si+{sup 20}Ne, {sup 24}Mg+{sup 24}Mg, and {sup 32}S+{sup 16}O, and for binary decay of the {sup 24}Mg+{sup 20}Ne reaction into low-lying states of {sup 24}Mg+{sup 20}Ne and {sup 28}Si+{sup 16}O. The {sup 28}Si+{sup 20}Ne measurements span the region of excitation energy in {sup 48}Cr from 50.6 to 67.7 MeV ({sup 28}Si beam energies from 87.2 to 128.2 MeV). The reaction {sup 24}Mg+{sup 20}Ne was investigated over a region in {sup 44}Ti from 48.75 to 71.0 MeV ({sup 24}Mg beam energies from 70.8 to 119.75 MeV). Angular distribution measurements were made for {sup 20}Ne({sup 28}Si,{sup 24}Mg){sup 24}Mg at excitation energy=56.22 MeV and for {sup 20}Ne({sup 24}Mg,{sup 16}O){sup 28}Si at excitation energy=53.02 and 57.75 MeV. Both systems display evidence of statistically significant correlated resonance phenomena, but the resonances are dominated by spins comparable to the grazing angular momenta of the respective entrance channels, and are not analogs of the molecular configurations that dominate the {sup 24}Mg({sup 24}Mg,{sup 24}Mg{sup *}){sup 24}Mg{sup *} reactions.