Determination of energy gap directly from phase shift for nuclear systems with large neutron excess

Considering ¹S₀ pairing in infinite neutron matter and nuclear matter, and knowing the fact that in the lowest order approximation, the pairing interaction has been taken to be the bare nucleon-nucleon interaction in the ¹S₀ channel, the energy gap has been determined directly from the ¹S₀ phase shifts. The values of energy gaps have been found to increase rapidly for low values of phase shifts, up to around 16°, and it is roughly constant with a value approximately equal to 1.08 MeV for phase shifts1 greater than 16°. (author)