For Feynman graph calculation of processes with a higher order correction or SUSY processes, a huge number of graphs are involved. Using automatic graph calculation package, we can generate the information of all graphs for such processes. Of all graphs sometimes we have to choose graphs by some conditions, however, it is not so easy to select them correctly by hands. We have developed a tool to select Feynman graphs within a framework of GRACE system. According to selection conditions given in a script file, a subset of Feynman graphs is selected from the set of graphs generated by GRACE. All information of selected graphs can be stored in the same format as that of the original set. Thus we can perform cross section calculation, gauge invariance check, event generation and so on for the selected ones. This tool is written in C language and it consists of three parts: an interpreter to parse and evaluate commands in a script file, definitions of basic graph selections, and a utility to handle subsets of particles, vertices and graphs.

Back to Program

Back to ACAT Web page