Banca de QUALIFICAÇÃO: DIEGO DOMINGUES LOPES

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : DIEGO DOMINGUES LOPES
DATA : 16/08/2019
HORA: 14:00
LOCAL: na sala 303, 3º andar, Bloco B, Campus SA da Fundação Universidade Federal do ABC, localizada na Avenida dos Estados, 5001, Santa Terezinha, Santo André, SP
TÍTULO:

THEORY AND PHENOMENOLOGY OF AXION LIKE PARTICLES

PÁGINAS: 50
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Física
SUBÁREA: Física das Partículas Elementares e Campos
ESPECIALIDADE: Teorias Específicas e Modelos de Interação; Sistemática de Partículas; Raios Cósmicos
RESUMO:

In this work will present the results gathered until now in the doctorate. Firstly we show a general discussion about the axions and axion-like particles (ALPs) theory. Then we discuss the study of an Standard Model extension, based on the $SU(3)_C\otimes SU(3)_L\otimes U(1)_X$ gauge symmetry that relates the mass hierarchy of the fermions with the solution to the strong CP problem through the $U(1)_{PQ}$ Peccei-Quinn symmetry. This last symmetry arises accidentally with the imposition of a discrete $\ZZ_9$ symmetry, which also secludes the different scales in the double seesaw mechanism taking place in the neutrino sector. The symmetry breakdown is performed by three scalar triplets plus a scalar singlet hosting an axion field, whose particle excitation can be a component of dark matter. We show a mechanism that gives rise to a natural hierarchy to the fermions.

Fosslowing we discuss a phenomenological work in wich we present prospects to probe the ALP couplings to sterile neutrinos. We found that mono-photon searches have the potential to constrain ALP couplings to sterile neutrinos when a new heavy scalar boosts the ALP decay yields. Working within an effective field theory (EFT) approach, we scan the parameters space to establish the reach of the 13 TeV LHC to probe such couplings. We found that some regions of the parameters space evading several current experimental and theoretical constraints can be probed with 300 fb$^{-1}$. We also present an UV-complete model for axion-like particles and dark fermions whose parameters are spanned by our EFT approach.

Finally we present as a perspective a new project to further studies, where we intend to analyze $S^2 a^2$ couplings with an heavy scalar and an ALP looking for exotics final states that may appear from this interaction.

MEMBROS DA BANCA:
Presidente - Interno ao Programa - 1544422 - EDUARDO DE MORAES GREGORES
Membro Titular - Examinador(a) Interno ao Programa - 1260948 - MARCOS DONIZETI RODRIGUES SAMPAIO
Membro Titular - Examinador(a) Interno ao Programa - 1770888 - CELIO ADREGA DE MOURA JUNIOR
Membro Suplente - Examinador(a) Externo ao Programa - 3057567 - CHEE SHENG FONG