Investigation of alternative mechanisms to neutrino oscillations in the MINOS experiment

Author(s)

João de Abreu Barbosa Coelho

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Física Gleb Wataghin
• Defense date: 2012-02-28

Examining board members

Carlos Ourivio Escobar; Pedro Cunha de Holanda; Ernesto Kemp; Ricardo Avelino Gomes; Hiroshi Nunokawa

• Advisor: Carlos Ourivio Escobar

Abstract

The neutrino oscillation model is very successful in explaining a large variety of experiments. The model is based on the premise that the neutrinos that interact through the weak force via charged current are not mass eigenstates, but a superposition of them. In general, a quantum superposition is subject to loss of coherence, so that pure states tend toward mixed states. This type of evolution is not possible within the context of isolated quantum systems because the evolution is unitary and, therefore, is invariant under time reversal. By breaking unitarity, an arrow of time is introduced and the characteristic effect for neutrinos is a damping of oscillations. In this thesis, some phenomonological decoherence and decay models are investigated, which could be observed by MINOS, a neutrino oscillation experiment that consists of measuring the neutrino ux produced in a particle accelerator 735 km away. We analyse the disappearance of muon neutrinos in MINOS. Information from other experiments is used to constrain the number of parameters, leaving only one extra parameter in each model. We assume a power law energy dependence of the decoherence parameter. The o-cial MINOS software and simulation are used to obtain the experiment's sensitivities to the eects of unitarity breaking considered (AU)

• FAPESP's process: 07/08188-8 - Alternative Mechanisms Investigation for the Results of Neutrino Oscillation in the MINOS Experiment.
• Grantee: João de Abreu Barbosa Coelho
• Support Opportunities: Scholarships in Brazil - Doctorate