Search for the Standard Model Scalar Boson with the ATLAS detector

The experimental results of the search for the Standard Model Higgs boson with the ATLAS detector at the Large Hadron Collider are reported, based on a dataset of pp collision data with an integrated luminosity of up to 4.9 fb^-1 at sqrt{s}=7 TeV. The search combines several Higgs boson decay channels in a wide range of Higgs boson masses from 110 GeV to 600 GeV. A Standard Model Higgs boson is excluded at the 95% confidence level in the mass ranges from 110.0 GeV to 117.5 GeV, 118.5 GeV to 122.5 GeV, and 129 GeV to 539 GeV, while the range from 120 GeV to 555 GeV is expected to be excluded in the absence of a signal. The most significant excess of events is observed around 126 GeV with a local significance of 2.5sigma. The global probability for such an excess to occur in the full searched mass range is approximately 30%.Comment: 8 pages, 14 pages, Proceedings for Recontres de Moriond EW 201

Focus topics for the ECFA study on Higgs / Top / EW factories

In order to stimulate new engagement and trigger some concrete studies in areas where further work would be beneficial towards fully understanding the physics potential of an $e^+e^-$ Higgs / Top / Electroweak factory, we propose to define a set of focus topics. The general reasoning and the proposed topics are described in this document.Comment: v3: fixed spelling of two author

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements