Eur. Phys. J. C (2017) 77: 568
https://doi.org/10.1140/epjc/s10052-017-5113-1

Regular Article - Theoretical Physics

Status of the scalar singlet dark matter model

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, Australia
http://www.coepp.org.au/
³ Department of Physics, University of Oslo, 0316, Oslo, Norway
⁴ SUPA, School of Physics and Astronomy, University of Glasgow, Glasgow, G12 8QQ, UK
⁵ Physik-Institut, Universität Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
⁶ H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, 31-342, Kraków, Poland
⁷ Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Centre, 10691, Stockholm, Sweden
⁸ Department of Physics, Stockholm University, 10691, Stockholm, Sweden
⁹ Department of Physics, McGill University, 3600 rue University, Montreal, QC, H3A 2T8, Canada
¹⁰ Department of Physics, University of Adelaide, Adelaide, SA, 5005, Australia
¹¹ DESY, Notkestraße 85, 22607, Hamburg, Germany
¹² NORDITA, Roslagstullsbacken 23, 10691, Stockholm, Sweden
¹³ Department of Physics, Blackett Laboratory, Imperial College London, Prince Consort Road, London, SW7 2AZ, UK
¹⁴ Univ Lyon, Univ Lyon 1, ENS de Lyon, CNRS, Centre de Recherche Astrophysique de Lyon UMR5574, 69230, Saint-Genis-Laval, France
¹⁵ Theoretical Physics Department, CERN, 1211, Geneva 23, Switzerland
¹⁶ Physics and Astronomy Department, University of California, Los Angeles, CA, 90095, USA
¹⁷ LAPTh, Université de Savoie, CNRS, 9 chemin de Bellevue, B.P.110, 74941, Annecy-le-Vieux, France
¹⁸ Department of Physics, Harvard University, Cambridge, MA, 02138, USA
¹⁹ Centre for Translational Data Science, Faculty of Engineering and Information Technologies, School of Physics, The University of Sydney, Sydney, NSW, 2006, Australia
²⁰ GRAPPA, Institute of Physics, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands

^* e-mail: j.mckay14@imperial.ac.uk

Received: 15 March 2017
Accepted: 26 July 2017
Published online: 23 August 2017

Abstract

One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a symmetry. Using the GAMBIT package and combining results from four independent samplers, we present Bayesian and frequentist global fits of this model. We vary the singlet mass and coupling along with 13 nuisance parameters, including nuclear uncertainties relevant for direct detection, the local dark matter density, and selected quark masses and couplings. We include the dark matter relic density measured by Planck, direct searches with LUX, PandaX, SuperCDMS and XENON100, limits on invisible Higgs decays from the Large Hadron Collider, searches for high-energy neutrinos from dark matter annihilation in the Sun with IceCube, and searches for gamma rays from annihilation in dwarf galaxies with the Fermi-LAT. Viable solutions remain at couplings of order unity, for singlet masses between the Higgs mass and about 300 GeV, and at masses above 1 TeV. Only in the latter case can the scalar singlet constitute all of dark matter. Frequentist analysis shows that the low-mass resonance region, where the singlet is about half the mass of the Higgs, can also account for all of dark matter, and remains viable. However, Bayesian considerations show this region to be rather fine-tuned.