McMule

Yannick Ulrich [1], Pulak Banerjee [2], Antonio Coutinho [3], Tim Engel [4], Andrea Gurgone [5], Franziska Hagelstein [6], Sophie Kollatzsch [7] [8], Luca Naterop [7] [8], Marco Rocco [7], Nicolas Schalch [9], Vladyslava Sharkovska [7] [8], Adrian Signer [7] [8], Zach McBrearty [10]

[1]

Department of Mathematical Sciences, University of Liverpool, Liverpool, L69 3BX, United Kingdom

[2]

Istituto Nazionale di Fisica Nucleare, Gruppo collegato di Cosenza, I-87036 Arcavacata di Rende, Cosenza, Italy

[3]

IFIC, Universitat de València - CSIC, Parc Científic, Catedrático José Beltrán, 2, E-46980 Paterna, Spain

[4]

Albert-Ludwigs-Universität Freiburg, Physikalisches Institut, Hermann-Herder-Straße 3, D-79104 Freiburg, Germany

[5]

Università di Pisa, Largo B. Pontecorvo 3, 56127, Pisa, Italy

[6]

Institut für Kernphysik & PRISMA⁺ Cluster of Excellence, Johannes Gutenberg Universität Mainz, D-55099 Mainz, Germany

[7] (1,2,3,4,5)

Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland

[8] (1,2,3,4)

Physik-Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

[9]

Rudolf Peierls Centre for Theoretical Physics, Clarendon Laboratory, Parks Road, University of Oxford, Oxford OX1 3PU, UK

[10]

Institute for Particle Physics Phenomenology, Durham, DH1 3LE, U.K

Contents:

• Getting started
  • Obtaining the code
  • Simple runs at LO
  • Running at NLO and beyond
  • More complicated runs
• Structure of McMule
  • The user function
  • Modular structure of libmcmule
  • What happens when running
• Observable validator
  • Using the validator
  • Logging Levels
  • Measurement function tests in detail
  • Distance function tests in detail
• General aspects of using McMule
  • Flavour
  • Statistics
  • Analysis
  • Manual compilation
• The menu file and pymule batch
  • Menu file syntax
  • Configuration file
• libmcmule user guide
  • Parameters, variables, and functions of libmcmule
  • The user file in Fortran
  • The user file in C/C++
• pymule user guide
  • Working with files
  • Working with errors
  • Plotting
• Technical aspects of McMule
  • Particle string framework
  • Phase-space generation
  • Implementation of FKS schemes
  • Calling procedures and function pointers
  • Optional parameters for integrands
  • Random number generation
  • Differential distributions and intermediary state files
  • Basics of containerisation
• Implementing new processes in McMule
  • Creating a new process group
  • Study of \(\xi_{c}\) dependence
  • Example calculations in Mathematica
  • Coding style and best practice
• The FKS\(^2\) scheme
  • FKS\(^\ell\): extension to N\(^\ell\)LO
• Glossary
  • Acronyms
  • Technical terms
• Bibliography
• Particle ID
• Available processes and which_piece
• libmcmule reference guide
  • The particle framework
  • Matrix element interface
  • Package-X function
  • VP functions
  • Phase spaces
• pymule reference guide
  • Working with errors
  • Working with abstract records
  • Working with vegas records
  • Working with records of data
  • Working with \(\xi_c\) data
  • Working with plots
  • Useful other functions
  • Validator

(Monte carlo for Muons and other leptons) is a generic framework for higher-order QED calculations of scattering and decay processes involving leptons. It is written in Fortran 95 with two types of users in mind. First, several processes are implemented, some at NLO, some at NNLO. For these processes, the user can define an arbitrary (infrared safe), fully differential observable and compute cross sections and distributions. McMule’s processes, present and, future, are listed in Table 8 together with the relevant experiments for which the cuts are implemented. Second, the program is set up s.t. additional processes can be implemented by supplying the relevant matrix elements.

Table 8 Processes implemented in McMule

process	order	experiments	comments
\(\mu\to\nu\bar\nu e\)	NNLO	MEG, DUNE	polarised, massified & exact
\(\mu\to\nu\bar\nu e\gamma\)	NLO	MEG, Mu3e, Pioneer	polarised
\(\mu\to\nu\bar\nu eee\)	NLO	MEG, Mu3e	polarised
\(\mu\to\nu\bar\nu e\gamma\gamma\)	LO	MEG	polarised
\(\tau\to\nu\bar\nu e\gamma\)	NLO	BaBar	cuts in lab frame
\(\tau\to\nu\bar\nu l\ell\ell\)	NLO	Belle II
\(e^+e^-\to \mu^+\mu^-\)	NNLO	MUonE	massified mixed corrections
\(\ell p\to\ell p\)	NNLO	MUSE, Prad, ULQ2, Amber	dipole approximation for TPE
\(eN\to eN\)	NNLO	Prad, ULQ2	electronic corrections only
\(e^-e^-\to e^-e^-\)	NNLO	Prad2, MOLLER	complete
\(e^+e^-\to e^+e^-\)	NNLO
\(e^+e^-\to \gamma\gamma\)	NNLO	Daphne
\(e^+e^-\to \mu^+\mu^-\)	NNLO	VEPP, BES, Daphne, Belle	massified mixed corrections
\(e^+e^-\to \ell^+\ell^-\gamma\)	NLO	VEPP, BES, Daphne
\(e^+e^-\to \pi^+\pi^-\)	NLO	VEPP, BES, Daphne

The public version of the code can be found at

https://gitlab.com/mule-tools/mcmule

To obtain a copy of the code, git is recommended

$ git clone --recursive https://gitlab.com/mule-tools/mcmule

Alternatively, we provide pre-compiled binaries for Linux systems on our website.

We provide instructions on how is used in Section Getting started.

Indices and tables

• Index

• Module Index

• Search Page