CP violation in the grimus-neufeld model /

One of the biggest unsolved issues in particle physics is the imbalance between matter and antimatter. This is closely related to the topic of CP violation, which refers to the phenomenon when the same processes treat matter and antimatter particles differently. Searching for the sources of CP violation inevitably leads to expansions of the Standard Model by new particles and interactions. One possible expansion of the Standard Model is the Grimus-Neufeld model, which introduces a single Majorana neutrino and an additional Higgs doublet. The model, originally created to describe neutrino mass generation, might also provide new sources for CP violating behavior. The addition of Majorana neutrino might allow the application of Grimus-Neufeld model to models of leptogenesis – a cosmological scenario, where matter-antimatter imbalance in the early Universe was created due to CP violating decays of heavy sterile neutrino. The goal of our work is to evaluate CP violation in the decays of Majorana neutrinos within the Grimus-Neufeld extension of the Standard Model. More specifically, we calculate the parameter of CP violation in one-loop approximation of Grimus-Neufeld model. Since most models of leptogenesis require CP violation to manifest in high temperatures, before the advent of symmetry breaking, we also calculate the CP parameter when all light leptons are assumed to be massless. Our results show that Majorana neutrino decays into specific lepton flavors are generally CP violating, in one loop approximation of the model, while in non-hierarchical mass limit this CP violation disappears.

Grantor dc:publisher

Institutional Repository of Vilnius University

Year dc:date

2024

Author dc:creator

• Mišeikis, Jokūbas,

• CP violation, Grimus-Neufeld model, Majorana neutrino decays.

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

eng

Repository record dc:identifier

https://repository.vu.lt/VU:ELABAETD210579652&prefLang=en_US

OAI identifier oai:identifier

oai:vu.lt:elaba:210579652