Giuliano Gustavino

Mono-jet Analysis Improvements

The mono-jet results based on the first 3.2\(~\text {fb}^{-1}\) of data collected in pp collisions at \(\sqrt{s} = 13 ~\text {TeV}\) at ATLAS have confirmed the contribution of this final state to the search for Dark Matter and new physics phenomena and its complementarity with respect to other analyses and experiments.

The Standard Model

The Standard Model is the theory that has been able to explain most of the phenomenology of the microscopic world and to identify its elementary constituents. Experimental evidences of its validity come from experiments of High Energy Physics of the twentieth and twenty-first centuries. This chapter briefly describes the Standard Model and the role of the Higgs boson in the theory.

Beyond the Standard Model

The Standard Model is not believed to be the fundamental and complete theory to describe Nature for several unsolved and still unexplained limitations. In this chapter a few observed anomalies will be outlined and an overview of the supersymmetric and the extra-spatial dimensions theories will be given which provide solutions to these deficiencies.

Mono-jet Versus All

The DM interpretations of the mono-jet limits are relevant and give complementary results with respect to the other analyses performed at collider experiments, but also to results obtained by experiments based on direct and indirect detection of DM.

The Mono-jet Analysis

In this chapter a detailed overview of the first Run-2 mono-jet analysis based on data collected during the first year of ATLAS at \(\sqrt{s}=13~\text {TeV}\) is provided (consult also Ref. (Aaboud et al., ATLAS Collaboration, Phys Rev D 94(3):032005, 2016, [1])). The selection criteria, the fitting strategy and the background estimations are addressed as well as the improvements and innovations introduced, which led to a significant improvement in sensitivity with respect to the Run-1 analysis. Finally the systematic uncertainties implemented in a global simultaneous fit are described and the results with the interpretations in the context of DM production, SUSY compressed scenarios and ADD model are presented.

The Dark Matter Paradigm

Although the existence of Dark Matter (DM) is well-established to explain a range of astrophysical and cosmological measurements, its nature and particle properties still remain one of the greatest unsolved puzzles of particle and astroparticle physics (Bertone and Hooper, Phys Rept 405:279 (2005), [1]).