In a measurement of the pp differential cross section, the result d/d 0.111 b/steradian was obtained at a laboratory energy of 4.2 MeV and a

In a measurement of the pp differential cross section, the result dσ/dΩ 0.111 b/steradian was obtained at a laboratory energy of 4.2 MeV and a laboratory scattering angle of 30°. What is the corresponding s-wave phase shift?