# SHELL2: a package for the calculation of two-loop on-shell Feynman diagrams in FORM

## Description

Abstract The description of a program written in FORM for the analytic calculation of propagator-type one- and two-loop Feynman graphs with external lines corresponding to massive as well as massless particles on-shell is presented. Dimensional regularization to regularize both ultraviolet and infrared divergences is used. The program calculates the contributions from any such diagram for an arbitrary value of the space-time dimension n in terms of one “master integral” and two simple integrals expres... Title of program: SHELL2 Catalogue Id: ACHZ_v1_0 Nature of problem Dimensionally regularized multiloop massive Feynman integrals of the propagator type appearing in quantum field theory and in particular in high energy calculations are computed analytically. Versions of this program held in the CPC repository in Mendeley Data ACHZ_v1_0; SHELL2; 10.1016/0010-4655(92)90083-B This program has been imported from the CPC Program Library held at Queen's University Belfast (1969-2019)