Baryon Number Violation in Extra Dimensions

Abstract

Matter-antimatter asymmetry is one of the most profound mysteries in the universe, with Baryon Number Violation (BNV) being one of the conditions to explain it. This thesis ex plores an extra-dimensional approach to address this problem by orbifolding a six-dimensional space-time onto the T2/Z3 geometry. We investigate the behaviour of Standard Model fields in this framework and study BNV processes such as nucleon decay (∆B = 1), dinucleon decay (∆B = 2), neutron-antineutron oscillations(∆B = 2), and assisted nucleon decay (∆B =1=∆L)toderive constraints on new physics scales. The compactification of extra dimensions breaks the six-dimensional Lorentz generator into a four-dimensional component and a residual U(1)zz∗ symmetry, which further reduces to Z6 upon orbifolding. We compute the limits for nucleon decay and neutron-antineutron oscilla tions, finding new physics scales of approximately 2.49×105 GeV and 45.23 GeV, respectively. Additionally, we examine dark matter-assisted nucleon decay, deriving a scalar dark matter mass limit of around 10 TeV. Our results highlight the potential of extra-dimensional models to address BNV and matter antimatter asymmetry while also providing testable predictions for future experiments.