K+ signatures in the protodune-sp detector at cern
- Autores: Miguel Angel García
- Directores de la Tesis: Anselmo Cervera-Villanueva (dir. tes.)
- Lectura: En la Universitat de València ( España ) en 2023
- Idioma: español
- Tribunal Calificador de la Tesis: Flavio Cavanna (presid.), Pau Novella Garijo (secret.), Inés Gil Botella (voc.)
- Programa de doctorado: Programa Oficial de Doctorado en Física
- Materias:
- Enlaces
- Tesis en acceso abierto en: TESEO
- Resumen
Neutrinos are the second most abundant particle in the Universe, yet the less understood. The discovery of their flavor oscillations have demonstrated that neutrinos are massive, constituting the first proof of physics beyond the Standard Model. During the last twenty years, tens of experiments have worked to measure the different parameters describing the oscillation phenomena using solar, atmospheric, reactor and accelerator neutrinos. However, some of these parameters have not been measured precisely enough, among which the CP violation phase stands. This phase quantifies how differently neutrinos and antineutrinos oscillate, and a value different from zero could be one of the ingredients to explain the existence of the Universe itself.
For this reason, the DUNE experiment has been proposed to keep studying neutrinos beyond. It will be a long-baseline neutrino experiment located at the US, and it will consist in the most neutrino beam ever produced, and two detectors to characterize the oscillated and the unoscillated neutrino flux. The Far Detector, located 1.5 km underground in SURF, will be using the emerging and outstanding Liquid Argon Time Projection Chamber detector technology at a scale never used before, combined with the novel X-ARAPUCA technology for photon detection. The excellent physics possibilities of DUNE allows it to expand its physics programme to also include proton decay searches, multi-messenger astronomy and a wide range of BSM physics.
Before the starting of the installation of DUNE, the ProtoDUNE program has been developed at CERN to validate the LArTPC technology. The largest prototypes of DUNE have been built and exposed to a charged particle beam to study the performance of this kind of experiments. In this work, we explore the capabilities of the ProtoDUNE-SP detector to identify low energy kaons by means of their calorimetric information, which is fundamental for the viability of proton decay searches in DUNE's FD. A sample of 1200 secondary stopping kaons has been obtained with a purity of 50%, demonstrating the LArTPC capabilities to perform proton decay searches, and allowing to perform a thoughtful analysis of the kaons' dE/dx. It has been found than apparently the MC simulation is underestimating the energy loss at very low energies. This result, after further confirmation, will be used to correct the simulation and to improve the proton decay sensitivity studies.
In addition to this, this work presents the result of the SiPM down-selection procedure developed by DUNE, in which the SiPM model to be used in the Photon Detection System. Sensors of two different vendors, HPK and FBK, were tested in cryogenic conditions, finding that larger pitch model with higher quenching resistances were preferred due to a reduction on the correlated noise probability. It was also found that, in general terms, HPK's SiPMs performed better than FBK's.
