Física (Dr.)
Permanent URI for this collectionhttp://98.81.228.127/handle/20.500.12404/6344
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Item Heavy neutrino production and decay at DUNE Near Detector(Pontificia Universidad Católica del Perú, 2024-08-13) Carbajal Vigo, Saneli Alcides; Gago Medina, Alberto MartínEn la presente tesis se estudia el potencial del DUNE Near Detector (DUNEND) para establecer límites a neutrinos pesados (HNL). Esto es realizado a través de un estudio de cómo los HNL afectan las tasas de producción y las distribuciones angulares de los neutrinos activos. Se demuestra que la producción de HNL en DUNE produce un déficit de eventos de corriente cargada (CC) en el Liquid Argon Time Proyection Chamber (LArTPC) de DUNEND y se utiliza esto para estimar la sensibilidad de DUNE a HNLs. Nuestro análisis revela que la sensibilidad depende fuertemente de las incertidumbres sistemáticas en las predicciones del flujo de neutrinos de DUNE. Asumiendo 10 años de operación (5 en modo neutrino y 5 en modo antineutrino) se obtienen los límites |Uμ4|2 < 9×10−3(4×10−2) y |Ue4|2 < 7×10−3(3×10−2) para masas por debajo de 10 MeV y una incertidumbre del 5%(20%) en la normalización de la predicción de los eventos de corriente cargada de neutrinos. Estos límites son mejores que aquellos que pueden ser alcanzados por las búsquedas directas en DUNE para masas por debajo de los 2(10) MeV. Para el caso de una incertidumbre conservadora del 20%, los límites obtenidos solo pueden mejorar los límites experimentales actuales en |Ue4|2 por un factor de 3 en una pequeña región alrededor de 5 eV y establecer límites en |Uμ4|2 en una región de masas libre de restricciones (40 eV - 1 MeV).Item Testing pALPIDE sensors for particle detection and Characterization of a Laser beam using a webcam CMOS sensor(Pontificia Universidad Católica del Perú, 2023-01-16) Soncco Meza, Carlos; Gago Medina, Alberto MartínThe upgrade program of the Large Hadron Collider (LHC) was implemented during the second Long Shutdown program (2019/2020). For this program, the ALICE Collaboration (A Large Ion Collider Experiment) proposed, among others, a new detector called Muon Forward Tracker (MFT). The primary goal of the MFT detector, installed on December 2021 and located between the Inner Tracker System (ITS) and the Muon Spectrometer, is to improve the capability of vertex reconstruction. The MFT is equipped with the same pixel sensors used for the ITS upgrade. These sensors are the ALICE Pixel Detectors (ALPIDE), a kind of monolithic active pixel sensor. The MFT is composed of five arrays of pixel sensors which are configured as parallel discs covering −3.6 < η < −2.45. Some prototypes were designed in order to achieve the final version of the ALPIDE, such as the pALPIDE family, which was divided into three versions (i.e., pALPIDE-1,2,3). The ALICE upgrade also included a new system for the data taking and simulation called Online-offline (O2) to replace AliRoot. We designed the geometry of two non-active parts of the MFT and included them in the O2 system. The first goal of this thesis is focused on the characterization of the pALPIDE-2. This sensor is segmented into four groups corresponding to four types of pixels. This characterization includes the test of analogue and digital. According to these tests, we identified a group of pixels that do not work correctly. The threshold scan tests showed the threshold level in each pixel is influenced by the input capacitance according to its n-well size and the surrounding area. Also, we studied the response of the pALPIDE-2 when it was exposed to a soft x-ray source, varying the distance between them. This test showed that the hit count changed according to the inverse square of the distance. iv The second goal of this thesis was to implement a low-cost tool based on a CMOS sensor to characterize laser beams. This tool comprises a Raspberry, a Pi Camera with a pitch size of 1.4 µm, and an optical system. To test the accuracy of the results of this tool, we made similar measurements with other sensors. A photodiode and a light-dependent resistor performed these measurements, which showed the spot radius size compatibility. However, the CMOS sensor expressed the highest precision and is a more affordable tool than commercial devices.Item Testing new physics in long baseline neutrino oscillation experiments(Pontificia Universidad Católica del Perú, 2023-01-10) Díaz Desposorio, Félix Napoleón; Gago Medina, Alberto MartínIn this thesis, we focus on analyzing the different ways in which new physics scenarios, such as Violation of the Equivalence Principle (VEP) and Quantum Decoherence, can manifest themselves in the context of the neutrino oscillation phenomenon. Within the framework of the DUNE experiment, we examine several effects of the VEP, such as the possibility of getting a misconstructed neutrino oscillation parameter region provoked by our ignorance of VEP in nature, as well as the impact on the DUNE sensitivity for CPV and mass hierarchy. Additionally, we set limits for the different textures of the gravitational matrix and the diverse scenarios of energy dependencies associated with the Lorentz Violation. On the other hand, we demonstrate that the quantum decoherence phenomenon applied to the neutrino system leads us to fascinating phenomenological scenarios. One of the scenarios analyzed, within the context of quantum decoherence, is the one that breaks the fundamental CPT symmetry. For the latter, we identify what textures that include certain nondiagonal elements of the decoherence matrix are necessary. In this line, we propose a way to measure the CPT violation in the DUNE experiment using the muon neutrino and antineutrino channels for different energy dependencies. Another intriguing effect of considering the neutrino as an open quantum system is the possibility of discovering the neutrino nature by measuring the Majorana phase at the DUNE experiment achieving a competitive precision. As a consequence of the latter, we find that the crucial measurement of the CP violation phase (δCP), planned to be performed at the DUNE experiment, can be spoiled by the introduction of the decoherence and the Majorana phases in nature. Thus, a signature of a non-null Majorana phase is a sizable distortion in the measurement of the Dirac CP violation phase δCP at DUNE when compared with T2HK measurement. Subsequently, via simulation, we measured the Majorana phase for values of ϕ1/π = ±0.5 and decoherence parameter Γ = 4.5(5.5) × 10−24GeV, reaching a precision of 23 (21) %. This precision is consistent with the corresponding to the Dirac CP phase at T2K experiment.