The Lippman-Schwinger equation for two-nucleon scattering

If you use Gauss-Legendre the points are determined for the interval \( x_i\in [-1,1] \) You map these points over to the limits in your integral. You can then use the following mapping $$ k_i=const\times tan\left\{\frac{\pi}{4}(1+x_i)\right\}, $$ and $$ \omega_i= const\frac{\pi}{4}\frac{w_i}{cos^2\left(\frac{\pi}{4}(1+x_i)\right)}. $$ If you choose units fm$^{-1}$ for \( k \), set \( const=1 \). If you choose to work with MeV, set \( const\sim 200 \) (\( \hbar c=197 \) MeVfm).