TSIL is a library of utilities for the numerical calculation of dimensionally regularized two-loop self-energy integrals. It is written in C, and can be linked to C/C++ and Fortran applications. The authors are Stephen P. Martin and David G. Robertson. TSIL is free software, released under the GPL. The paper announcing and describing TSIL can be downloaded from the hep-ph preprint archive as hep-ph/0501132. The source code for the current version (v1.46, July 2025) of the program can be downloaded here as a gzipped tar file: tsil-1.46.tar.gz. This unpacks into a single directory, which contains the C source files and a README.txt file with complete instructions for building and using TSIL.

In the Hopi culture indigenous to the American southwest, Tsil is the Chili Pepper Kachina, one of many supernatural spirits represented by masked doll-like figurines and impersonated by ceremonial dancers. Tsil is one of the runner Kachinas. When he overtakes you in a race, he may stuff your mouth with hot chili peppers.

The README.txt file is here. You can also peruse the CHANGELOG.txt file here.

For applications to the Standard Model Higgs, Z, W, and top-quark masses, look at SMDR.

For an application to the computation of the gluino pole mass, look at gluinopole.

TSIL can also be obtained from https://davidgrobertson.github.io/TSIL/.

This material is based upon work supported by the National Science Foundation under Grants PHY-0140129, PHY-0456635, PHY-0757325, PHY-1068369, PHY-1417028, PHY-1719273, 2013340, and 2310533. This work is also supported by awards from Research Corporation and the Ohio Supercomputer Center.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.