# GAMBIT -- a Global And Modular Bsm Inference Tool

Modern science usually provides both copious amounts of data and complicated models for the part of reality it is trying to describe. Often there is even so much data, and the models so complicated, that it becomes difficult to make full use of the data in deciding which models best describe the world around us, and finding their properties. The main goal of the GAMBIT project is to develop a software tool to help physicists do just that.

## About the project

We live in the time of Big Data. Our fantastic technical ability to measure and record the world around us with great precision floods us with information. This is true both in our daily lives and in science. Mirroring this, our understanding of the world has advanced to very detailed and complicated models in most fields; models with many parameters and with great predictive power for many possible measurements. The data and the models have even become so unwieldy as to pose a problem: we are constantly challenged to apply the full power of the data to our models, in order to decide between competing models, and to establish the properties of a particular model.

It was to meet this challenge, particularly in the field of particle and astroparticle physics, that we started the GAMBIT Collaboration in the summer of 2012 with the aim to develop a modular set of software tools for doing proper statistical inference on physics models. The small group of a dozen or so initial members has since grown to a large community of over 60 active researchers, spanning the globe, with members as far away as California and southern Australia. Together, this community continues to develop a large software base for use in physics, and uses the developed tools to explore physics models, as well as working on more general aspects of statistical inference in physics, writing reviews and recommendations of best practice for the larger physics community.

## Collaboration

The GAMBIT community is currently led from the University of Oslo by Anders Kvellestad who has been elected Head of the GAMBIT Collaboration for the period 2021-2024 after serving for six years as the leader of the Collider Physics Working Group in GAMBIT.

The GAMBIT community consists of over 60 physicist, both theorists and experimentalists with some weight to the former, coming from all over the world, and covering a wide array of fields such as particle physics, astroparticle physics, astrophysics and cosmology. Current participating institutions are: Aachen University, University of Adelaide, University of Cambridge, CERN, the GRAPPA Institute, University of Amsterdam, Imperial College London, University of Glasgow, UCLA, Université catholique de Louvain, Monash University, Technical University Munich, Nanjing Normal University, the Oskar Klein Centre, Stockholm University and the University of Zurich. The community includes members of the AMS-02, ATLAS, CDMS, CMS, CTA, DARWIN, DM-ICE, Fermi-LAT, HESS, IceCube, LHCb and XENON experiments, as well as developers of the open source codes Capt'n General, DarkSUSY, DDCalc, FlexibleSUSY, HEPLike, gamLike, GM2Calc, IsaJet, nulike, SoftSUSY, SuperIso, Vevacious and xsec.

## Outcomes

We are currently on version 1.5.1 of the GAMBIT software after releasing the first version in May 2017. The open source code, together with documentation, can be found on HepForge and as a GitHub repository.

In addition to the GAMBIT code base the GAMBIT community has published a large number of peer reviewed papers detailing the code, applications in searches for new physics, and reviews and recommendation. Publications with a significant contribution from University of Oslo researchers is listed below. For all physics papers the GAMBIT community also releases the corresponding data and relevant code snippets on the Zenodo data repository.

## Financing

Initial work on GAMBIT in Oslo was partially financed by the Research Council of Norway (RCN) in the period 2014--2018 through a four-year FRIPRO grant for young research talents with Are Raklev as Principle Investigator. It was also supported (2015--2019) by the

## Selected publications

#### Code descriptions

*CosmoBit: A GAMBIT module for computing cosmological observables and likelihoods,* The GAMBIT Cosmology Workgroup (J.J. Renk *et al.*), arXiv:2009.03286 [astro-ph.CO].

*GAMBIT: The Global and Modular Beyond-the-Standard-Model Inference Tool*, The GAMBIT Collaboration (P. Athron *et al.*), Eur. Phys. J. C 77 (2017) 11, 784, e-Print: arXiv:1705.07908 [hep-ph].

*ColliderBit: a GAMBIT module for the calculation of high-energy collider observables and likelihoods*, The GAMBIT Collider Workgroup (C. Balázs *et al.*), Eur. Phys. J. C 77 (2017) 11, 795, arXiv:1705.07919 [hep-ph].

*SpecBit, DecayBit and PrecisionBit: GAMBIT modules for computing mass spectra, particle decay rates and precision observables*, The GAMBIT Models Workgroup (P. Athron *et al.*), Eur. Phys. J. C 78 (2018) 1, 22, arXiv:1705.07936 [hep-ph].

*DarkBit: A GAMBIT module for computing dark matter observables and likelihoods*, The GAMBIT Dark Matter Workgroup (T. Bringmann *et al.*), Eur. Phys. J. C 77 (2017) 12, 831, arXiv:1705.07920 [hep-ph].

*FlavBit: A GAMBIT module for computing flavour observables and likelihoods*, The GAMBIT Flavour Workgroup (F.U. Bernlochner *et al.*), Eur. Phys. J. C 77 (2017) 11, 786, arXiv:1705.07933 [hep-ph].

*Comparison of statistical sampling methods with ScannerBit, the GAMBIT scanning module,* The GAMBIT Scanner Workgroup (G.D. Martinez *et al.*), Eur. Phys. J. C 77 (2017) 11, 761, arXiv:1705.07959 [hep-ph].

**Physics papers**

*Strengthening the bound on the mass of the lightest neutrino with terrestrial and cosmological experiments,* The GAMBIT Cosmology Workgroup (P. Stöcker *et al.*), arXiv:2009.03287 [astro-ph.CO].

*Combined collider constraints on neutralinos and charginos*, The GAMBIT Collaboration (P. Athron *et al.*), Eur. Phys. J. C 79 (2019) 5, 395, arXiv:1809.02097 [hep-ph].

*Global analyses of Higgs portal singlet dark matter models using GAMBIT*, The GAMBIT Collaboration (P. Athron *et al.*), Eur. Phys. J. C 79 (2019) 1, 38, arXiv:1808.10465 [hep-ph].

*Status of the scalar singlet dark matter model, *The GAMBIT Collaboration (P. Athron *et al.*), Eur. Phys. J. C 77 (2017) 8, 568, arXiv:1705.07931 [hep-ph].

*Global fits of GUT-scale SUSY models with GAMBIT*, The GAMBIT Collaboration (P. Athron *et al.*), Eur. Phys. J. C 77 (2017) 12, 824, arXiv:1705.07935 [hep-ph].

*A global fit of the MSSM with GAMBIT*, The GAMBIT Collaboration (P. Athron *et al.*), Eur. Phys. J. C 77 (2017) 12, 879, arXiv:1705.07917 [hep-ph].

**Reviews and best-practice papers**

*Reinterpretation of LHC Results for New Physics: Status and Recommendations after Run 2*, W. Abdallah *et al.*, SciPost Phys. 9 (2020) 2, 022, arXiv:2003.07868 [hep-ph].

*GAMBIT and its Application in the Search for Physics Beyond the Standard Model*, A. Kvellestad, P. Scott, M. White, Progress in Particle and Nuclear Physics 113 (2020), 103769, arXiv:1912.04079 [hep-ph].