Joint theory/experiment seminar

Wednesday 12 Sept 2018, 13:15 → 14:00 Europe/Oslo

Ullevål

Eirik Gramstad (University of Oslo (NO))

13:20 → 13:40 Global analyses of Higgs portal singlet dark matter models using GAMBIT

The most economical way to extend the Standard Model by gauge singlet dark matter is by coupling to the Higgs doublet. These models are simple, but still show rich phenomenology. However, increasingly sensitive direct dark matter searches reveal the need to add complexity to models to be consistent with all constraints. I will show results of global fits, using GAMBIT, for the cases where dark matter is a spin-1/2 and a spin-1 particle, from both a frequentist and a Bayesian perspective.

Speaker: Sanjay Bloor (Imperial College London)

UiO.pdf

13:40 → 14:00 Combined collider constraints on neutralinos and charginos

I will present the latest study on supersymmetry from the GAMBIT collaboration, where we have investigated the combined collider constraints on the MSSM "electroweakinos" (neutralinos and charginos), assuming that other SUSY particles are decoupled. Using GAMBIT, we have performed a large-scale global fit where we incorporate simulations of recent ATLAS and CMS SUSY searches, in addition to constraints from SUSY searches at LEP and the invisible decay widths of the Z and Higgs bosons. We find that when working in the general four-dimensional parameter space of the MSSM electroweakino sector, the current data do not robustly exclude any range of electroweakino masses. Further, a series of excesses in the LHC searches provides a hint of a signal, preferring a scenario where all the electroweakinos are lighter than ~500 GeV.

Speaker: Anders Kvellestad (Nordita)