Sascha Caron

A description of the Galactic Center excess in the Minimal Supersymmetric Standard Model

Observations with the Fermi Large Area Telescope (LAT) indicate an excess in gamma rays originating from the center of our Galaxy. A possible explanation for this excess is the annihilation of Dark Matter particles. We have investigated the annihilation of neutralinos as Dark Matter candidates within the phenomenological Minimal Supersymmetric Standard Model (pMSSM). An iterative particle filter approach was used to search for solutions within the pMSSM. We found solutions that are consistent with astroparticle physics and collider experiments, and provide a reasonable fit to the energy spectrum of the excess. The neutralino is a Bino/Higgsino mixture and a mass in the range

Profile likelihood maps of a 15-dimensional MSSM

84-92

Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector

~GeV yielding a Dark Matter relic density

Search for long-lived, massive particles in events with displaced vertices and missing transverse momentum in s =13 TeV pp collisions with the ATLAS detector

0.06 < \Omega h^2 <0.13

Search for heavy resonances decaying into a W or Z boson and a Higgs boson in final states with leptons and b-jets in 36 fb(-1) of √s = 13 TeV pp collisions with the ATLAS detector

. These pMSSM solutions make clear forecasts for LHC, direct and indirect DM detection experiments. If the pMSSM explanation of the excess seen by Fermi-LAT is correct, a DM signal might be discovered soon.

Search for new phenomena in high-mass final states with a photon and a jet from pp collisions at √s=13 TeV with the ATLAS detector

A bstractWe present statistically convergent profile likelihood maps obtained via global fits of a phenomenological Minimal Supersymmetric Standard Model with 15 free parameters (the MSSM-15), based on over 250M points. We derive constraints on the model parameters from direct detection limits on dark matter, the Planck relic density measurement and data from accelerator searches. We provide a detailed analysis of the rich phenomenology of this model, and determine the SUSY mass spectrum and dark matter properties that are preferred by current experimental constraints. We evaluate the impact of the measurement of the anomalous magnetic moment of the muon (g − 2) on our results, and provide an analysis of scenarios in which the lightest neutralino is a subdominant component of the dark matter. The MSSM-15 parameters are relatively weakly constrained by current data sets, with the exception of the parameters related to dark matter phenomenology (M1, M2, μ), which are restricted to the sub-TeV regime, mainly due to the relic density constraint. The mass of the lightest neutralino is found to be < 1.5 TeV at 99% C.L., but can extend up to 3 TeV when excluding the g − 2 constraint from the analysis. Low-mass bino-like neutralinos are strongly favoured, with spin-independent scattering cross-sections extending to very small values, ~ 10−20 pb. ATLAS SUSY null searches strongly impact on this mass range, and thus rule out a region of parameter space that is outside the reach of any current or future direct detection experiment. The best-fit point obtained after inclusion of all data corresponds to a squark mass of 2.3 TeV, a gluino mass of 2.1 TeV and a 130 GeV neutralino with a spin-independent cross-section of 2.4 × 10−10 pb, which is within the reach of future multi-ton scale direct detection experiments and of the upcoming LHC run at increased centre-of-mass energy.

Searches for the Zγ decay mode of the Higgs boson and for new high-mass resonances in pp collisions at √s=13 TeV with the ATLAS detector

A search for the associated production of the Higgs boson with a top quark pair (tt̄H) is reported. The search is performed in multilepton final states using a dataset corresponding to an integrated luminosity of 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at a center-of-mass energy √ s = 13 TeV at the Large Hadron Collider. Higgs boson decays toWW∗, ττ, and Z Z∗ are targeted. Seven final states, categorized by the number and flavor of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the tt̄H production cross section is σ(tt̄H) = 790+230 −210 fb, in agreement with the Standard Model prediction of 507+35 −50 fb. The combination of this result with other tt̄H searches from the ATLAS experiment using the Higgs boson decay modes to bb̄, γγ and Z Z∗ → 4`, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the tt̄H production mode.

Searches for scalar leptoquarks in pp collisions at √s = 8 TeV with the ATLAS detector

A search for long-lived, massive particles predicted by many theories beyond the Standard Model is presented. The search targets final states with large missing transverse momentum and at least one high-mass displaced vertex with five or more tracks, and uses 32.8 fb−1 of √ s = 13 TeV pp collision data collected by the ATLAS detector at the LHC. The observed yield is consistent with the expected background. The results are used to extract 95% CL exclusion limits on the production of long-lived gluinos with masses up to 2.37 TeV and lifetimes of O(10−2)–O(10) ns in a simplified model inspired by Split Supersymmetry.

Higgs, di-Higgs and tri-Higgs production via SUSY processes at the LHC with 14 TeV

A bstractA search is conducted for new resonances decaying into a W or Z boson and a 125 GeV Higgs boson in the νν¯bb¯