Likelihood analysis of the pMSSM11 in light of LHC 13-TeV data

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

doi:10.1140/epjc/s10052-018-5697-0

2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2018) 78: 256
https://doi.org/10.1140/epjc/s10052-018-5697-0

Regular Article - Theoretical Physics

Likelihood analysis of the pMSSM11 in light of LHC 13-TeV data

E. Bagnaschi¹^*, K. Sakurai², M. Borsato³, O. Buchmueller⁴, M. Citron⁴, J. C. Costa⁴, A. De Roeck⁵^,6, M. J. Dolan⁷, J. R. Ellis⁸^,9^,10, H. Flächer¹¹, S. Heinemeyer¹²^,13^,14, M. Lucio³, D. Martínez Santos³, K. A. Olive¹⁵, A. Richards⁴, V. C. Spanos¹⁶, I. Suárez Fernández³ and G. Weiglein¹

¹ DESY, Notkestraße 85, 22607, Hamburg, Germany
² Faculty of Physics, Institute of Theoretical Physics, University of Warsaw, ul. Pasteura 5, 02-093, Warsaw, Poland
³ Instituto Galego de Física de Altas Enerxías, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
⁴ High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ, UK
⁵ Experimental Physics Department, CERN, 1211, Geneva 23, Switzerland
⁶ Antwerp University, 2610, Wilrijk, Belgium
⁷ ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, 3010, Melbourne, 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 William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
¹⁶ Section of Nuclear and Particle Physics, Department of Physics, National and Kapodistrian University of Athens, 15784, Athens, Greece

^* e-mail: emanuele.bagnaschi@desy.de

Received: 16 November 2017
Accepted: 3 March 2018
Published online: 24 March 2018

Abstract

We use MasterCode to perform a frequentist analysis of the constraints on a phenomenological MSSM model with 11 parameters, the pMSSM11, including constraints from $\sim 36$ /fb of LHC data at 13 TeV and PICO, XENON1T and PandaX-II searches for dark matter scattering, as well as previous accelerator and astrophysical measurements, presenting fits both with and without the $(g-2)_\mu$ constraint. The pMSSM11 is specified by the following parameters: 3 gaugino masses $M_{1,2,3}$ , a common mass for the first-and second-generation squarks $m_{\tilde{q}}$ and a distinct third-generation squark mass $m_{\tilde{q}_3}$ , a common mass for the first-and second-generation sleptons $m_{\tilde{\ell }}$ and a distinct third-generation slepton mass $m_{\tilde{\tau }}$ , a common trilinear mixing parameter A, the Higgs mixing parameter $\mu$ , the pseudoscalar Higgs mass $$M_A$$ and $\tan \beta$ . In the fit including $(g-2)_\mu$ , a Bino-like $\tilde{\chi }^0_{1}$ is preferred, whereas a Higgsino-like $\tilde{\chi }^0_{1}$ is mildly favoured when the $(g-2)_\mu$ constraint is dropped. We identify the mechanisms that operate in different regions of the pMSSM11 parameter space to bring the relic density of the lightest neutralino, $\tilde{\chi }^0_{1}$ , into the range indicated by cosmological data. In the fit including $(g-2)_\mu$ , coannihilations with $\tilde{\chi }^0_{2}$ and the Wino-like $\tilde{\chi }^\pm _{1}$ or with nearly-degenerate first- and second-generation sleptons are active, whereas coannihilations with the $\tilde{\chi }^0_{2}$ and the Higgsino-like $\tilde{\chi }^\pm _{1}$ or with first- and second-generation squarks may be important when the $(g-2)_\mu$ constraint is dropped. In the two cases, we present $\chi ^2$ functions in two-dimensional mass planes as well as their one-dimensional profile projections and best-fit spectra. Prospects remain for discovering strongly-interacting sparticles at the LHC, in both the scenarios with and without the $(g-2)_\mu$ constraint, as well as for discovering electroweakly-interacting sparticles at a future linear $$e^+ e^-$$ collider such as the ILC or CLIC.