Total crossection is 4 pi sin^(delta_0)/k^2 not the one which is written in the solution. I just want the correct solution
14. In a measurement of the pp differential cross section, the result do/ds = 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?