Busca da matéria escura por meio de detecção direta: reconstrução e estudo de eventos gerados por múons no experimento COSINE-100

Abstract

The nature of dark matter is one of the main subjects of study today. Although we can infer its presence in the universe, for example, through observation of its gravitational effects, its composition is still in debate. To resolve this issue, many experiments have been and are being carried out. To date, none of them has shown sufficient evidence for a definitive conclusion. However, one of them, the DAMA/LIBRA experiment, claims to have achieved conclusive results on the nature of dark matter by observing an annual modulation in the events obtained in its NaI(Tl) crystal scintillators, although such results are not confirmed by other experiments. To obtain a verdict on the result of the DAMA/LIBRA experiment, the COSINE-100 experiment was idealized, which uses the same type of detectors to confirm or refute the observations of the DAMA/ LIBRA. The COSINE-100 experiment has been in operation since 2016 at the Yangyang laboratory (Y2L), South Korea. To ensure good data analysis, there is a great deal of effort in the study of background radiation present in the experiment, in addition to its prevention with various active and passive shielding layers. One of the most important radiations studied are muons, which can be candidates for explaining the results of the DAMA/LIBRA experiment, as they also present an annual modulation and can cause events with energy similar to that expected for dark matter in crystal detectors. In order to deepen the study of this type of radiation and improve the selection of events in the experiment, in this work methods for reconstructing the trajectory of muons, as well as the direction of their flow through the experimental setup are studied.