Beyond the Standard Model Physics, from the LHC to Fixed Target Experiments and Astrophysical Probes
Abstract
The Standard Model (SM) of particle physics, while excruciatingly consistent underprecision testing, is not a complete theory. Theories of new physics beyond the Stan- dard Model (BSM) thrive beyond its shortcomings. This thesis will explore several complementary avenues of investigation in this realm. The first part concerns CP violation (CPV) in the theory of a two Higgs doublet model (2HDM), and the signature of electric dipole moments (EDMs) is considered. Subject to constraints on EDMs set by experiments, collider phenomenology is explored and a benchmark is elaborated. An astrophysical interlude proceeds with a statistical treatment proposed to distinguish microlensing events in which lensing objects are drawn from populations of free floating planets (FFPs) or from populations of primordial black holes (PBHs). The Nancy Grace Roman Space Telescope, set to launch in 2027, will observe a suffi- cient number of events during its Galactic Bulge Time Domain Survey to enable such statistical tools. The third part discusses a pair of BSM models where additional particles contribute to the muon anomalous moment, a µ . First, the flavorful supersymmetric Standard Model (FSSM) is described, and its contributions to a µ are computed. It is shown that sleptons in the multi-TeV range can ameliorate the recently measured tension in a µ . Second, a minimal extension to the SM with an addition scalar coupling to muons is described, and the detection reach of the proposed DarkQuest experiment is computed. Mitigation strategies on various sources of backgrounds are discussed in detail.