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Accueil > Thèses, Stages, Formation et Enseignement > Propositions de thèses 2024 > Light dark matter search in XENONnT experiment and the challenge of single electron background

Light dark matter search in XENONnT experiment and the challenge of single electron background

par Tristan Beau - 24 novembre 2023

Titre : Light dark matter search in XENONnT experiment and the challenge of single electron background

Directrice/directeur de thèse : Luca Scotto Lavina

Co-encadrant.e : Elisabetta Barberio

Groupe d’accueil :XENON

Webpage du projet :

Collaboration : XENON and XeLab

Description :

Shedding light on the nature of dark matter is one of the main priority of modern particle and astroparticle physics today. Direct detection experiments aim to scope the particle dark matter models where this mysterious particle, travelling through our galaxy, might scatter off targets of ultra-sensitive, low-background detectors in Earth. One of the leading technologies today are the dual-phase liquid xenon Time Projection Chambers (TPC). The size of the detectors that are currently operating is so large that a new background is challenging our capability to detect light dark matter, composed by isolated electrons or small electron clusters. This background is currently under study in XENONnT, and we expect that for the next-generation DARWIN detector, it would be even larger, despite our efforts on xenon purification and a careful choice of detector materials. With this project, we aim to take in charge two challenges for XENONnT and DARWIN : from hardware side, we are developing novel electrodes that will be tested in our small-scale TPC installed at LPNHE, named XeLab. We plan to characterize this background source, eventually by generating it by purpose inside XeLab, with the goal of measuring the relevant physical parameters required to develop a strong background model. From the data analysis side, we intend to develop a series of cuts that will improve the suppression of those electrons, by improving the current sensitivity of XENONnT. The candidate will have therefore the chance to work on the data analysis of XENONnT which is one of the most sensitive experiments to dark matter to date, and at the same time will operate a local Liquid Xenon TPC.

The candidate is encouraged to start an M2 internship in our group. The activities we propose in 2024 for the internship are dual as well. From one side, he/she will participate in the test of a new algorithm that classifies tiny ionization signals, with the goal to characterise and eventually separate the different background components. From the other side, we will start the commissioning of XeLab, which is a great occasion to see a TPC starting detecting its first light.

Lieu(x) de travail : LPNHE

Déplacements éventuels : LNGS Underground Laboratory, Italy and University of Melbourne

Stage proposé avant la thèse : Oui

Nota : The thesis might be funded by the Joint CNRS-Melbourne PhD Program. The result of the funding will be known only in January 2024. If selected, the candidate is encouraged to spend one year of the thesis in Australia at the University of Melbourne, where our collaborators would transfer their expertise on data acquisition and PMTs characterization. In that case, a dedicated budget will be available (5k euros per year) on top of the student’s salary.

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