The Weinberg operator at same-sign muon-muon colliders

The Standard Model (SM) of particle physics describes how fundamental particles interact. Experimental observations are well-explained by the SM but some questions still remain. One of these questions has to do with neutrinos: how are their masses generated and how do we treat the masses? The Standard Model Effective Field Theory (SMEFT) is an effective field theory that provides a possible answer. The SMEFT Lagrangian expands the SM Lagrangian in canonical dimensions of 1/Λ, where Λ ≫ mW is the scale of New Physics (NP). The SM Lagrangian has dimension D = 4, but the SMEFT Lagrangian allows for higher dimension terms. At D = 5, the so-called “Weinberg operator” generates Majorana neutrino masses. In this project I investigate the possibility of probing the Weinberg operator at a same-sign muon-muon collider. I simulate the Weinberg operator using MadGraph5 and discuss the possibility of observing it in a potential future collider.