Efeitos das dimensões extras em sistemas atômicos e o problema do raio do próton

• Ano de defesa: 2018
• Autor(a) principal: Lêmos, Adiel da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Física; Programa de Pós-Graduação em Física; UFPB
• Palavras-chave em Português: Dimensões extras; Brana; Espectroscopia; Problema do raio do próton; Extra dimensions; Braneworld; Spectroscopy; Proton radius puzzle; CNPQ::CIENCIAS EXATAS E DA TERRA::FISICA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/13147

Unification theories that include gravitation, such as the Kaluza-Klein theory and string theory, predict the existence of the supplementary space. Motivated by large extra dimensions theory, we explicitly examined the influence of the postulates extradimensionality of spacetime on atomic systems where the usual four-dimensional gravitational effects are negligible. Initially, we present a complementary method to constrain the extra-dimensional models through the spectroscopy of hydrogen-like atoms. Assuming that the gravitational potential energy, modified by the existence of extra dimensions, can be treated as a small perturbation in comparison to the atomic Hamiltonian, we found empirical bounds on the radius of the extra dimensions – or, alternatively, on the higher-dimensional Planck mass – more stringent than those obtained through the Large Hadron Collider (LHC). Subsequently, we addressed the proton radius puzzle that deals with the incompatibility between the theoretical predictions derived fromQuantumElectrodynamics(QED)andexperimentalmeasurementsinvolvingtransitions in electronic and muonic hydrogen atoms. This puzzle presents itself as an energy excess in the measurement of the Lamb Shift in muonic hydrogen compared to the theoretical prediction calculated with the proton radius value recommended by CODATA. We show that this energy excess, in the thick brane scenario, can be explained by the gravitational interaction amplified by the extra dimensions. Thus, this would be the first evidence of the supposed spatial extra dimensions.