Glossary
Acronyms
- BR
a branching ratio
- EW
electroweak
- FKS
the Frixione-Kunszt-Signer scheme used in McMule. See Section The FKS^2 scheme.
- FSR
final state radiation
- IR
infra-red
- HVP
hadronic vacuum polarisation
- ISR
initial state radiation
- LO
leading order
- LP
leading power
- NLO
next-to-leading order
- NLP
next-to-leading power
- NNLO
next-to-next-to-leading order
- NTS
next-to-soft
- OS
on-shell renormalisation scheme in which the masses correspond to the poles of the propagators and \(\alpha=\alpha(q^2=0)\) in the Thomson limit
- PCS
pseudo-collinear sinuglarities, the numerical instabilties in
\[\mathcal{M}_{n+1}^{(\ell )} \propto \frac{1}{q\cdot k} = \frac1{\xi^2}\frac1{1-y\beta}\]where \(y\) is the angle between photon (\(k\)) and electron (\(q\)). For large velocities \(\beta\) (or equivalently small masses), this becomes almost singular as \(y\to1\).
- 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
- 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)
- event
the hard event that does not get subtracted in FKS, cf. (6)
- full period
a surjective RNG
- generic pieces
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 processes
A generic process is a prototype for the physical process such as \(\ell p\to\ell p\) where the flavour of the lepton \(\ell\) is left open.
A menu file contains a list of jobs to be computed s.t. the user will only have to vary the random seed and \(\xi_{c}\) 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.
- process group
Processes are grouped into process grous if they share matrix elements such as \(\mu\to\nu\bar\nu e\) and \(\mu\to\nu\bar\nu e\gamma\) (
mudec
) or \(e\mu\to e\mu\) and \(\ell p\to\ell p\) (mue
).- random seed
the initial value of the RNG. In McMule this may be between 1 and 2<sup>31</sup>-2. See Section Random number generation for further details.
- soft cut
a value of \(\xi\) 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.