Eur. Phys. J. C (2019) 79: 38
https://doi.org/10.1140/epjc/s10052-018-6513-6

Regular Article - Theoretical Physics

Global analyses of Higgs portal singlet dark matter models using GAMBIT

¹ School of Physics and Astronomy, Monash University, Melbourne, VIC, 3800, Australia
² Australian Research Council Centre of Excellence for Particle Physics at the Tera-scale, Melbourne, Australia
³ Department of Physics, University of Adelaide, Adelaide, SA, 5005, Australia
⁴ Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, 10691, Stockholm, Sweden
⁵ Department of Physics, Stockholm University, 10691, Stockholm, Sweden
⁶ Blackett Laboratory, Department of Physics, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK
⁷ Department of Physics, McGill University, 3600 rue University, Montréal, QC, H3A 2T8, Canada
⁸ Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
⁹ Department of Physics, University of Oslo, 0316, Oslo, Norway
¹⁰ Institute for Theoretical Particle Physics and Cosmology (TTK), RWTH Aachen University, 52056, Aachen, Germany
¹¹ Physics and Astronomy Department, University of California, Los Angeles, CA, 90095, USA
¹² Arthur B. McDonald Canadian Astroparticle Physics Research Institute, Department of Physics, Engineering Physics and Astronomy, Queen’s University, Kingston, ON, K7L 3N6, Canada
¹³ DESY, Notkestraße 85, 22607, Hamburg, Germany

^* e-mail: sanjay.bloor12@imperial.ac.uk

Received: 11 September 2018
Accepted: 9 December 2018
Published online: 17 January 2019

Abstract

We present global analyses of effective Higgs portal dark matter models in the frequentist and Bayesian statistical frameworks. Complementing earlier studies of the scalar Higgs portal, we use GAMBIT to determine the preferred mass and coupling ranges for models with vector, Majorana and Dirac fermion dark matter. We also assess the relative plausibility of all four models using Bayesian model comparison. Our analysis includes up-to-date likelihood functions for the dark matter relic density, invisible Higgs decays, and direct and indirect searches for weakly-interacting dark matter including the latest XENON1T data. We also account for important uncertainties arising from the local density and velocity distribution of dark matter, nuclear matrix elements relevant to direct detection, and Standard Model masses and couplings. In all Higgs portal models, we find parameter regions that can explain all of dark matter and give a good fit to all data. The case of vector dark matter requires the most tuning and is therefore slightly disfavoured from a Bayesian point of view. In the case of fermionic dark matter, we find a strong preference for including a CP-violating phase that allows suppression of constraints from direct detection experiments, with odds in favour of CP violation of the order of 100:1. Finally, we present DDCalc 2.0.0, a tool for calculating direct detection observables and likelihoods for arbitrary non-relativistic effective operators.