Precision radiative corrections to the semileptonic Dalitz plot with   angular correlation between polarized decaying and emitted baryons: Effects   of the four-body region
  Analytical radiative corrections of order (\alpha/\pi)(q/M_1) are calculated for the four-body region of the Dalitz plot of baryon semileptonic decays when the s_1 \cdot p_2 correlation is present. Once the final result is available, it is possible to exhibit it in terms of the corresponding final result of the three-body region following a set of simple changes in the latter. We cover two cases, a charged and a neutral polarized decaying baryon. 
J.J. Torres, M. Neri, A. Martinez, A. Garcia, Ruben Flores-Mendieta