2018/12/16 by Subhaditya Bhattacharya, Bhattacharya, Subhaditya, Purusottam Ghosh +5 · 6 citations
Computer Science · Physics and Astronomy · #Computational Physics and Python Applications #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.1812.06505
openalex publication_date 2018/12/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We review a class of models in which the Standard Model (SM) is augmented by\nvector-like leptons: one doublet and a singlet, which are odd under an unbroken\ndiscrete Z2 symmetry. As a result, the neutral component of these additional\nvector-like leptons are stable and behave as dark matter. We study the\nphenomenological constraints on the model parameters and elucidate the\nparameter space for relic density, direct detection and collider signatures of\ndark matter. In such models, we further add a scalar triplet of hypercharge two\nand study the consequences. In particular, after electro weak symmetry breaking\n(EWSB), the triplet scalar gets an induced vacuum expectation value (vev),\nwhich yield Majorana masses not only to the light neutrinos but also to\nvector-like leptonic doublet DM. Due to the Majorana mass of DM, the Z\nmediated elastic scattering with nucleon is forbidden and hence allowing the\nmodel to survive from stringent direct search bound. The DM without scalar\ntriplet lives in a small singlet-doublet leptonic mixing region (\sin\θ\n\≤ 0.1) due to large contribution from singlet component and have small mass\ndifference (\Δ m \∼ 10 GeV) with charged companion, the NLSP (next to\nlightest stable particle), to aid co-annihilation for yielding correct relic\ndensity. Both these observations change to certain extent in presence of scalar\ntriplet to aid observability of hadronically quiet leptonic final states at\nLHC, while one may also confirm/rule-out the model through displaced vertex\nsignal of NLSP, a characteristic signature of the model in relic density and\ndirect search allowed parameter space.\n