Full text
| |
| Author(s): |
César Peixoto Ferreira
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Física Gleb Wataghin |
| Defense date: | 2014-06-06 |
| Examining board members: |
Marcelo Moraes Guzzo;
Vicente Pleitez;
Marcus Aloizio Martinez de Aguiar
|
| Advisor: | Marcelo Moraes Guzzo |
| Abstract | |
In this dissertation, one of the extensions of the Standard Model of Elementary Particles(SM), known as the '3-3-1 Extension\', and its aplication to Cosmology are analysed. This class of models constitutes one of the most economical extensions of the Standard Model, and have among its qualities answers to open problems within the SM. Among them, we mention the generation problem and the quark mass assymetry problem. Both of these problems are answered trough the use of a internal consistency criterion of the model: The cancelation of chiral anomalies. The model chosen for study was the 3-3-1 Model with right handed neutrinos (3- 3-1RH), and all its main caracteristics are analysed. To aplications to Cosmology, the 3-3-1 was studied within the Dark Matter problem. In this case, we analyse dark matter candidates in one extension of the 3-3-1, known as the Left-Right 3- 3-1 Model (3L3R). These candidates are sterile neutrinos with keV masses, and to them cosmological limits are applied. These limits are the decays into X-Rays, Neff and Dark Matter Abundance. 3 cases were analysed: (1) Decoupling of the sterile neutrinos before muon annihilation; (2) Decoupling before pion annihilation; (3) Decoupling before Hadronization. The application of the limits mentioned above revealed that these neutrinos do not, at the moment, have any restrictions coming from decays into X-Rays, because this kind of decay is forbidden in the 3L3R. For each of the 3 cases, Neff had the value of 3.69, 3.53 e 3.09, respectively. When this is compared with the experimental value, Neff = 3:28 0:28, we conclude that in two cases, only one sterile neutrino is roughly allowed. In the remaining case, all 3 new neutrinos of the 3L3R are possible. The calculation of abundance revelead an excess of these neutrinos, using the method that is used to calculate abundance of active neutrinos. The calculated abundance is bigger than the experimentally determined in all possible cases, even when we consider a limit case. We conclude that some alternative mechanism for density dilution is necessary (AU) | |
| FAPESP's process: | 11/15339-8 - An analysis of the 3-3-1 extension of the Standard Model of Elementary Particles |
| Grantee: | César Peixoto Ferreira |
| Support Opportunities: | Scholarships in Brazil - Master |