This work presents searches for dark matter particles in the mono-jet and mono-photon final states using the data collected by the ATLAS experiment during 2015 and 2016. The thesis starts with an introduction to the basic concepts of the Standard Model, followed by a discussion of the dark matter problem and the WIMP hypothesis. The focus then shifts to the description of the experimental facilities to collect the data and reconstruct the collision events. Particular focus is put on the reconstruction and performance of the missing transverse momentum. After characterizing a few theoretical models predicting dark matter particles in the mono-photon and mono-jet final states, the searches in these two signatures are thoroughly discussed, with particular focus on the background estimation techniques. While no significant deviations from the Standard Model predictions are found, the results obtained by these searches further restrict the phase-space where the dark matter particles can lie.

SEARCHING FOR DARK MATTER IN THE MONO-JET AND MONO-PHOTON CHANNELS WITH THE ATLAS DETECTOR

RATTI, MARIA GIULIA
2018

Abstract

This work presents searches for dark matter particles in the mono-jet and mono-photon final states using the data collected by the ATLAS experiment during 2015 and 2016. The thesis starts with an introduction to the basic concepts of the Standard Model, followed by a discussion of the dark matter problem and the WIMP hypothesis. The focus then shifts to the description of the experimental facilities to collect the data and reconstruct the collision events. Particular focus is put on the reconstruction and performance of the missing transverse momentum. After characterizing a few theoretical models predicting dark matter particles in the mono-photon and mono-jet final states, the searches in these two signatures are thoroughly discussed, with particular focus on the background estimation techniques. While no significant deviations from the Standard Model predictions are found, the results obtained by these searches further restrict the phase-space where the dark matter particles can lie.
12-feb-2018
Inglese
dark matter; ATLAS; collider; high-energy; mono-jet; mono-photon; missing transverse momentum; missing transverse energy; t-channel model; dark matter models; beam-induced background; LHC; particle physics; particles; WIMP; physics; high-energy physics;
CARMINATI, LEONARDO CARLO
RAGUSA, FRANCESCO
CARMINATI, LEONARDO CARLO
Università degli Studi di Milano
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14242/169665
Il codice NBN di questa tesi è URN:NBN:IT:UNIMI-169665