PIKOE: A computer program for distorted-wave impulse approximation calculation for proton induced nucleon knockout reactions

PIKOE, Proton-Induced KnockOut reaction calculation for Exclusive processes, is a Fortran 90 program that calculates triple- and quadruple-differential cross sections, vector analyzing powers, and momentum distributions of reaction residues, for proton-induced nucleon knockout reactions in normal and inverse kinematics. The distorted-wave impulse approximation with the factorization approximation to the nucleon-nucleon transition matrix is adopted, and the distorted waves of the incoming proton and the outgoing two nucleons are calculated quantum mechanically. Kinematics of the reaction particles are treated in a relativistic manner, which gives the proper asymptotics of the three-body scattering wave in the plane-wave limit.PIKOE（全称为Proton-Induced KnockOut reaction calculation for Exclusive processes，即专用于遍举过程的质子诱发核子敲除反应计算程序）是一款Fortran 90程序，可针对正运动学与逆运动学下的质子诱发核子敲除反应，计算三重微分截面、四重微分截面、矢量分析本领以及反应残核的动量分布。 该程序采用扭曲波冲量近似（distorted-wave impulse approximation），并针对核子-核子跃迁矩阵应用因子化近似，同时通过量子力学方法计算入射质子与出射的两个核子的扭曲波。反应粒子的运动学采用相对论性处理，该处理可在平面波极限下给出三体散射波的正确渐近行为。