2025-05-122025-05-122025-04-03AZEVEDO, D. A. Estudo fenomenológico do decaimento invisível dos neutrinos nos experimentos MINOS e MINOS+. 2025. 158 f. Dissertação (Mestrado em Física) - Instituto de Física, Universidade Federal de Goiás, Goiânia, 2025.http://repositorio.bc.ufg.br/tede/handle/tede/14298The neutrino oscillation model is already well stablished; however, there is still interest in investigating phenomena that may occur alongside it. One of them being decay, already ruled out as happening alone, but can still occur with oscillation. Some of the recent analysis in the literature try to, using experimental data from accelerator experiments, have a measurement of the parameter τ3/m3, carrying information about the decay of the mass eigenstate ν3. The following work consider the data from the MINOS and MINOS+ long-baseline experiments, for different models of neutrino oscillation: the standard oscillation and the oscillation with decay in vacuum and in matter. From the Pνµ→νµ probability, and considering the charged current events of νµ, we want to show: how the presence of the MINOS+ data affects the results obtained with the MINOS experiment; we also implement the oscillation with decay in matter model, which is a more suited one as a proof of concept, considering that modern studies do consider the matter effects; a value for the τ3/m3 parameter. This analysis also yields a best fit value for the oscillation with decay in matter of the combined experimental data, having ∆m 2 32 = 2.226 × 10−3 eV2 , sin2 θ23 = 0.715 and a lower bound limit of 90% C.L. for the decay parameter of τ3/m3 > 1.52×10−12 s/eV.Acesso Abertohttp://creativecommons.org/licenses/by-nc-nd/4.0/Decaimento invisívelEfeito de matériaMINOSMINOS+NeutrinoOscilação de neutrinosOscilação com decaimentoInvisible decayMatter effectsNeutrino oscillationOscillation with decayCIENCIAS EXATAS E DA TERRA::FISICA::FISICA DAS PARTICULAS ELEMENTARES E CAMPOSDissertação