where $y$ is the angle between photon ( $k$ ) and electron ( $q$ ). For large velocities $β$ (or equivalently small masses), this becomes almost singular as $y \to 1$ .

PID

particle identification, the ordering of particles in the code

RNG

random number generator, used to generate pseudo-random numbers for the Monte Carlo generation. See Section Random number generation

SHA1

secure-hasing-algorithm-1, used for hashing McMule’s source code in autoversioning

SM

the Standard Model of particle physics

TOML

the name of the markup language used for config files. See https://toml.io/ for more information

VP

vacuum polarisation

Technical terms

config file: a shell file specifying, among other things, the statistics to be used
containerisation: the concept of bundling all dependecies etc. with McMule. See Sections Basics of containerisation and Basics of containerisation
container: a container that has bundled all dependecies etc. with McMule. See Sections Basics of containerisation and Basics of containerisation
corner region: a region of phase space where the mapping defined in Section Phase-space generation is not unique. The corner region refers to the smaller part of this double mapping.
counter-event: the soft event that gets subtracted in FKS, cf. (6)
distance function: A function which determines the distance between two points in the momentum phasespace.
event: the hard event that does not get subtracted in FKS, cf. (6)
executor: a pymule plugin that executes a menu file
fatal: A test which is not allowed to fail, such as the Soft photon limit or Swap symmetry tests.
full period: a surjective RNG
generic piece: a generic piece describes a part of the calculation such as the real or virtual corrections that themselves may be further subdivided as is convenient.
generic process: A generic process is a prototype for the physical process such as $ℓ p \to ℓ p$ where the flavour of the lepton $ℓ$ is left open.
image: a disk image that has bundled all dependecies etc. with McMule. See Sections Basics of containerisation and Basics of containerisation
menu file: A menu file contains a list of jobs to be computed s.t. the user will only have to vary the random seed and $ξ_{c}$ by hand as the statistical requirements are defined globally in a config file.
measurement function: A function that takes as arguments the four-momenta of all particles involved in the reaction and returns the experimentally measured quantity.
non-fatal: A test which is allowed to fail, but ideally shouldn’t. Includes most lorentz transformations.
process group: Processes are grouped into process grous if they share matrix elements such as $μ \to ν \bar{ν} e$ and $μ \to ν \bar{ν} e γ$ (mudec) or $e μ \to e μ$ and $ℓ p \to ℓ p$ (mue).
random seed: the initial value of the RNG. In McMule this may be between $1$ and $2^{31} - 2$ . See Section Random number generation for further details.
shared library: a library that can be loaded dynamically. On Linux system the customary filename suffix is .so. McMule can be used as a shared library and also load a shared library for the user file.
soft cut: a value of $ξ$ below which no subtraction takes place and the integrand is set to zero
submission script: a script that is provided by pymule to run a menu file.
userfile: the *.f95 or *.c file which defines the QUANT function or measurement function along with histogram variables.
which_piece: A which piece is a single subdivision of a generic piece designed to build up to a full calculation