Confronting physics puzzles in the Mirror Twin Higgs models

Abstract

In this research proposal, we will study the following physics puzzles in the context of Mirror Twin Higgs (MTH) models. First, we will study how family symmetry breaking at the weak scale accessible to Large Hadron Collider can explain the masses and mixing of observed fermions and also give rise to the required Z_2 breaking in the MTH. Secondly, we will study the generation of baryon asymmetry through leptogenesis and/or mirror leptogenesis in the MTH. We will study two possible scenarios: leptogenesis through decays with lepton number violating scale at M ~ 10^8 GeV and leptogenesis through oscillation with M ~ 1 GeV. In particular, the latter scenario has the benefit of being testable by low energy experiments. In the MTH, dark matter in the form of mirror baryon is stable due to dark baryon number and the connection to the baryon asymmetry in the SM is natural due to the mixing operator. Finally, in the MTH, the existence of light sterile neutrinos (mirror neutrinos) is natural. Due to the mixing operator, this can induce low scale leptonic unitarity violation which can be probed in neutrino oscillation experiments. (AU)