Chapter 12 Fit QC3

minimizing the \(\chi^2\) \[ \chi^2 =\sum_i \frac{(E_3^{predicted} -E_3^{measured} )}{\sigma^2} \] the predicted energy is the solution of the three particles quantization condition in the isotropic approximation \[ F_3^{iso}(E,\vec P,L)=-1/K^{iso}_3(E^*)\, \] \(F_3\) depend on the result of the two particle phase shift \(\delta\) computed before and \(K_3^{iso}\) is parametrised as

\[ K_3^{iso}= K^0_3+ \Delta K^1_3 \] with \(\Delta=(E_{cm}^2 -9 m^2)\)