Emanuele Bagnaschi

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Researcher at INFN Laboratori Nazionali di Frascati

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E. Bagnaschi (DESY), K. Sakurai (Warsaw U.), M. Borsato (U. Santiago de Compostela), O. Buchmueller (Imperial Coll., London), M. Citron (Imperial Coll., London), J.C. Costa (Imperial Coll., London), A. De Roeck (CERN and Antwerp U.), M.J. Dolan (Melbourne U.), J.R. Ellis (King’s Coll. London and CERN and NICPB, Tallinn), H. Flächer (Bristol U.), S. Heinemeyer (Cantabria U., Santander and Madrid, Autonoma U. and Madrid, IFT), M. Lucio (Santiago de Compostela U.), D. Martínez Santos (Santiago de Compostela U., IGFAE), K.A. Olive (Minnesota U., Theor. Phys. Inst.), A. Richards (Imperial Coll., London), V.C. Spanos (Natl. Tech. U., Athens), I. Suárez Fernández (Santiago de Compostela U., IGFAE), G. Weiglein (DESY)

Eur.Phys.J.C 78 (2018) 3, 256

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

e-print: 1710.11091 [hep-ph]

We use ${\tt MasterCode}$ 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.

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