SOFTSUSY 1 . 1 : a program for calculating supersymmetric spectra

SOFTSUSY is a program which accurately calculates the spectrum of su-perparticles in the Minimal Supersymmetric Standard Model (MSSM). The program solves the renormalisation group equations with theoretical constraints on soft su-persymmetry breaking terms provided by the user. Weak-scale gauge coupling and fermion mass data (including one-loop finite MSSM corrections) are used as a boundary condition, as well as successful radiative electroweak symmetry breaking. The program can also calculate a measure of fine-tuning. The program structure has been designed to easily generalise to extensions of the MSSM. This article serves as a self-contained guide to prospective users, and indicates the conventions and approximations used. Sample results are compared with similar calculations in the literature.