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Publication - Dr Emanuele Bagnaschi

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

    Citation

    Bagnaschi, E, Sakurai, K, Borsato, M, Buchmueller, O, Citron, M, Costa, JC, De Roeck, A, Dolan, MJ, Ellis, JR, Flächer, H, Heinemeyer, S, Lucio, M, Santos, DM, Olive, KA, Richards, A, Spanos, VC, Fernández, IS & Weiglein, G, 2018, ‘Likelihood analysis of the pMSSM11 in light of LHC 13-TeV data’. European Physical Journal C: Particles and Fields, vol 78.

    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 ∼ 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 M1 , 2 , 3, a common mass for the first-and second-generation squarks mq~ and a distinct third-generation squark mass mq~3, a common mass for the first-and second-generation sleptons mℓ~ and a distinct third-generation slepton mass mτ~, a common trilinear mixing parameter A, the Higgs mixing parameter μ, the pseudoscalar Higgs mass MA and tan β. In the fit including (g- 2) μ, a Bino-like χ~10 is preferred, whereas a Higgsino-like χ~10 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, χ~10, into the range indicated by cosmological data. In the fit including (g- 2) μ, coannihilations with χ~20 and the Wino-like χ~1± or with nearly-degenerate first- and second-generation sleptons are active, whereas coannihilations with the χ~20 and the Higgsino-like χ~1± or with first- and second-generation squarks may be important when the (g- 2) μ constraint is dropped. In the two cases, we present χ2 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.

    Full details in the University publications repository