Likelihood analysis of the sub-GUT MSSM in light of LHC 13-TeV data

J. C. Costa; E. Bagnaschi; K. Sakurai; M. Borsato; O. Buchmueller; M. Citron; A. De Roeck; M. J. Dolan; J. R. Ellis; H. Flächer; S. Heinemeyer; M. Lucio; D. Martínez Santos; K. A. Olive; A. Richards; G. Weiglein

doi:10.1140/epjc/s10052-018-5633-3

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2018) 78: 158
https://doi.org/10.1140/epjc/s10052-018-5633-3

Regular Article - Theoretical Physics

Likelihood analysis of the sub-GUT MSSM in light of LHC 13-TeV data

J. C. Costa¹^*, E. Bagnaschi², K. Sakurai³, M. Borsato⁴, O. Buchmueller¹, M. Citron¹, A. De Roeck⁵^,6, M. J. Dolan⁷, J. R. Ellis⁸^,9^,10, H. Flächer¹¹, S. Heinemeyer¹²^,13^,14, M. Lucio⁴, D. Martínez Santos⁴, K. A. Olive¹⁵, A. Richards¹ and G. Weiglein²

¹ High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ, UK
² DESY, Notkestraße 85, 22607, Hamburg, Germany
³ Faculty of Physics, Institute of Theoretical Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
⁴ Instituto Galego de Física de Altas Enerxías, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
⁵ Experimental Physics Department, CERN, 1211, Geneva 23, Switzerland
⁶ Antwerp University, 2610, Wilrijk, Belgium
⁷ School of Physics, ARC Centre of Excellence for Particle Physics at the Terascale, University of Melbourne, Parkville, 3010, Australia
⁸ Theoretical Particle Physics and Cosmology Group, Department of Physics, King’s College London, London, WC2R 2LS, UK
⁹ National Institute of Chemical Physics and Biophysics, Rävala 10, 10143, Tallinn, Estonia
¹⁰ Theoretical Physics Department, CERN, 1211, Geneva 23, Switzerland
¹¹ H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
¹² Campus of International Excellence UAM + CSIC, Cantoblanco, 28049, Madrid, Spain
¹³ Instituto de Física Teórica UAM-CSIC, C/ Nicolas Cabrera 13-15, 28049, Madrid, Spain
¹⁴ Instituto de Física de Cantabria (CSIC-UC), Avda. de Los Castros s/n, 39005, Santander, Spain
¹⁵ School of Physics and Astronomy, William I. Fine Theoretical Physics Institute, University of Minnesota, Minneapolis, MN, 55455, USA

^* e-mail: j.costa15@imperial.ac.uk

Received: 20 November 2017
Accepted: 10 February 2018
Published online: 23 February 2018

Abstract

We describe a likelihood analysis using MasterCode of variants of the MSSM in which the soft supersymmetry-breaking parameters are assumed to have universal values at some scale $M_\mathrm{in}$ below the supersymmetric grand unification scale $M_\mathrm{GUT}$ , as can occur in mirage mediation and other models. In addition to $M_\mathrm{in}$ , such ‘sub-GUT’ models have the 4 parameters of the CMSSM, namely a common gaugino mass $m_{1/2}$ , a common soft supersymmetry-breaking scalar mass $$m_0$$ , a common trilinear mixing parameter A and the ratio of MSSM Higgs vevs $\tan \beta$ , assuming that the Higgs mixing parameter $\mu > 0$ . We take into account constraints on strongly- and electroweakly-interacting sparticles from $\sim 36$ /fb of LHC data at 13 TeV and the LUX and 2017 PICO, XENON1T and PandaX-II searches for dark matter scattering, in addition to the previous LHC and dark matter constraints as well as full sets of flavour and electroweak constraints. We find a preference for $M_\mathrm{in}\sim 10^5$ to $10^9 \,\, \mathrm {GeV}$ , with $M_\mathrm{in}\sim M_\mathrm{GUT}$ disfavoured by $\Delta \chi ^2 \sim 3$ due to the $\mathrm{BR}(B_{s, d} \rightarrow \mu ^+\mu ^-)$ constraint. The lower limits on strongly-interacting sparticles are largely determined by LHC searches, and similar to those in the CMSSM. We find a preference for the LSP to be a Bino or Higgsino with $m_{\tilde{\chi }^0_{1}} \sim 1 \,\, \mathrm {TeV}$ , with annihilation via heavy Higgs bosons H / A and stop coannihilation, or chargino coannihilation, bringing the cold dark matter density into the cosmological range. We find that spin-independent dark matter scattering is likely to be within reach of the planned LUX-Zeplin and XENONnT experiments. We probe the impact of the $(g-2)_\mu$ constraint, finding similar results whether or not it is included.