| Thesis | |
| Report number | CERN-THESIS-2021-351 ; 10.25358/openscience-7448 |
| Title | Search for Axions at the LHC |
| Author(s) | Neuhaus, Friedemann (Johannes Gutenberg Universitaet Mainz (DE)) |
| Publication | 213. |
| Thesis note | PhD : Johannes Gutenberg-University Mainz : 2021-12-13 |
| Thesis supervisor(s) | Schott, Matthias |
| Note | Presented 06 Jul 2022 |
| Subject category | Particle Physics - Experiment ; Detectors and Experimental Techniques |
| Accelerator/Facility, Experiment | CERN LHC ; ATLAS CERN LHC ; FASER |
| Abstract | The Standard Model of Particle Physics (SM) is able to describe almost all measurements in particle physics with extraordinary precision. However, few phenomena within the greater scope of particle physics lack an explanation by the SM. Although there have been many searches for all kinds of new particles at the Large Hadron Collider (LHC), to the surprise of many physicists, no beyond Standard Model particle has been discovered to date. Most measurements focus on the search for heavy, centrally produced particles from interactions of two protons. As new particles do not have to be heavy but could be very light, these experiments cover only a fraction of the yet unexplored parameter space. In this thesis, two different approaches are presented to search for a group of light particles summarized under the term Axion-Like-Particles (ALPs). The first approach utilizes the LHC as a photon collider to probe for the resonant production of an ALP in photon-photon scattering within the ATLAS detector. This measurement not only results in the first direct observation of the light-by-light scattering process, but also to the most stringent limits on the ALP to photon coupling in a mass range of $m_a = 6 - 100\text{ GeV}$. The second search is based on a new experiment at the LHC called the FASER experiment. The experiment was installed in March 2021. Data taking will start once the LHC resumes operations in 2022. In this thesis, the contributions to the design and commissioning of the FASER detector are presented. This includes the development of a dedicated calibration system for the calorimeter and commissioning of various sub-systems. In addition, a possible design for a future detector upgrade is evaluated. Its realization will improve the sensitivity for ALP to di-photon decay signatures. |
Email contact: friedemann.neuhaus@cern.ch
Record created 2022-09-29, last modified 2022-10-05