Searching for dark matter in the quark top sector with the ATLAS detector
Description
The Standard Model is a very reliable theory describing our universe at the subatomic scale which has however some limitations. A model proposing a solution to the dark matter issue is studied in this report. This model predicts the existence of a spin-1 boson mediating the interactions between Standard Model particles and dark matter. It can lead to two signatures, either with one top quark or two same-sign tops, both needing to be studied. This report contains the same sign top analysis developed in the context of the ATLAS detector for collisions of 13 TeV, and the study dealing with the issue about combining both analyses. Firstly, the Standard Model and this model of New Physics are described. Then, the choice of a same-sign dilepton final state to lead the analysis is discussed, before an estimation of backgrounds. Eventually, a selection over the Ht variable is optimised, thus enabling the computation of a limit mass for the mediator, using the CLs method. (author)
Abstract (French)
Le Modele Standard est une theorie tres robuste decrivant notre monde a l'echelle elementaire qui presente cependant des limites. Dans ce rapport, est etudie un modele se proposant de resoudre une de ces limites: la matiere noire. Ce modele predit ainsi l'existence d'un boson vecteur vehiculant les interactions entre le Modele Standard et la matiere noire. Il peut mener a deux signatures, comportant soit un quark top (monotop) ou deux tops de meme signe (same-sign top) dans l'etat final, qui peuvent chacune faire l'objet d'une analyse. Ce rapport presente l'analyse same-sign top developpee aupres du detecteur ATLAS pour une energie de 13 TeV, ainsi qu'une etude sur la combinaison des deux analyses. Le Modele Standard et ce modele de Nouvelle Physique sont presentes dans un premier temps. Le choix de l'etude de la signature same-sign top a travers la signature experimentale comportant deux leptons de meme signe est ensuite justifie, avant que l'estimation des bruits de fond ne soit discutee. Une optimisation de la selection sur la variable Ht est effectue, permettant le calcul d'une masse limite du mediateur optimale par la methode CL_s. (auteur)
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Additional details
Additional titles
- Original title (French)
- Recherche de matiere noire dans le secteur du quark top avec le detecteur ATLAS
Publishing Information
- Imprint Pagination
- 37 p.
- Report number
- INIS-FR--25-0260
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- Subject category
- S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ATLAS DETECTOR; NONLUMINOUS MATTER; STANDARD MODEL; UNIVERSE; T QUARKS; SPIN; COSMOLOGY; LEPTONS; B QUARKS; MIXING ANGLE; INTERMEDIATE VECTOR BOSONS; LEPTOQUARKS; MASS
- Descriptors DEC
- ANGULAR MOMENTUM; BEAUTY PARTICLES; BOSONS; ELEMENTARY PARTICLES; FERMIONS; FIELD THEORIES; GRAND UNIFIED THEORY; INTERMEDIATE BOSONS; MATHEMATICAL MODELS; MATTER; MEASURING INSTRUMENTS; PARTICLE MODELS; PARTICLE PROPERTIES; POSTULATED PARTICLES; QUANTUM FIELD THEORY; QUARKS; RADIATION DETECTORS; TOP PARTICLES; UNIFIED GAUGE MODELS
- Proposed descriptors and Free-text terms
- dark matter; same-sign top; same-sign dilepton
Optional Information
- Notes
- 10 refs.; Available from the INIS Liaison Officer for France, see the INIS website for current contact and E-mail addresses