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

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

Eur Phys J C Part Fields. 2018;78(3):256. doi: 10.1140/epjc/s10052-018-5697-0. Epub 2018 Mar 24.

Authors

E Bagnaschi¹, K Sakurai², M Borsato³, O Buchmueller⁴, M Citron⁴, J C Costa⁴, A De Roeck^{5

6}, M J Dolan⁷, J R Ellis^{8

9

10}, H Flächer¹¹, S Heinemeyer^{12

13

14}, M Lucio³, D Martínez Santos³, K A Olive¹⁵, A Richards⁴, V C Spanos¹⁶, I Suárez Fernández³, G Weiglein¹

Affiliations

¹ 1DESY, Notkestraße 85, 22607 Hamburg, Germany.
² 2Faculty of Physics, Institute of Theoretical Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland.
³ 3Instituto Galego de Física de Altas Enerxías, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
⁴ 4High Energy Physics Group, Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2AZ UK.
⁵ 5Experimental Physics Department, CERN, 1211 Geneva 23, Switzerland.
⁶ 6Antwerp University, 2610 Wilrijk, Belgium.
⁷ 7ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, 3010 Melbourne, Australia.
⁸ 8Theoretical Particle Physics and Cosmology Group, Department of Physics, King's College London, London, WC2R 2LS UK.
⁹ 9National Institute of Chemical Physics and Biophysics, Rävala 10, 10143 Tallinn, Estonia.
¹⁰ 10Theoretical Physics Department, CERN, 1211 Geneva 23, Switzerland.
¹¹ 11H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL UK.
¹² 12Campus of International Excellence UAM+CSIC, Cantoblanco, 28049 Madrid, Spain.
¹³ 13Instituto de Física Teórica UAM-CSIC, C/ Nicolas Cabrera 13-15, 28049 Madrid, Spain.
¹⁴ 14Instituto de Física de Cantabria (CSIC-UC), Avda. de Los Castros s/n, 39005 Santander, Spain.
¹⁵ 15William I. Fine Theoretical Physics Institute, School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 USA.
¹⁶ 16Section of Nuclear and Particle Physics, Department of Physics, National and Kapodistrian University of Athens, 15784 Athens, Greece.

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 ${(g - 2)}_{μ}$ 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 $m_{\tilde{ℓ}}$ and a distinct third-generation slepton mass $m_{\tilde{τ}}$ , a common trilinear mixing parameter A, the Higgs mixing parameter $μ$ , the pseudoscalar Higgs mass $M_{A}$ and $tan β$ . In the fit including ${(g - 2)}_{μ}$ , a Bino-like ${\tilde{χ}}_{1}^{0}$ is preferred, whereas a Higgsino-like ${\tilde{χ}}_{1}^{0}$ is mildly favoured when the ${(g - 2)}_{μ}$ 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, ${\tilde{χ}}_{1}^{0}$ , into the range indicated by cosmological data. In the fit including ${(g - 2)}_{μ}$ , coannihilations with ${\tilde{χ}}_{2}^{0}$ and the Wino-like ${\tilde{χ}}_{1}^{\pm}$ or with nearly-degenerate first- and second-generation sleptons are active, whereas coannihilations with the ${\tilde{χ}}_{2}^{0}$ and the Higgsino-like ${\tilde{χ}}_{1}^{\pm}$ or with first- and second-generation squarks may be important when the ${(g - 2)}_{μ}$ constraint is dropped. In the two cases, we present $χ^{2}$ 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 ${(g - 2)}_{μ}$ constraint, as well as for discovering electroweakly-interacting sparticles at a future linear $e^{+} e^{-}$ collider such as the ILC or CLIC.