Leptophilic dark matter from gauged lepton number: phenomenology and gravitational wave signatures

Abstract

New gauge symmetries often appear in theories beyond the Standard Model.Here we study a model where lepton number is promoted to a gauge symmetry. Anomaly cancellation requires the introduction of additional leptons, the lightest of which is a natural leptophilic dark matter candidate. We perform a comprehensive study of both collider and dark matter phenomenology. Furthermore we find that the model exhibits a first order lepton number breaking phase transition in large regions of parameter space. The corresponding gravitational wave signal is computed, and its detectability at LISA and other future GW detectors assessed. Finally we comment on the complementarity of dark matter, collider and gravitational wave observables, and on the potential reach of future colliders.

Detecting gravitational waves from cosmological phase transitions with LISA: an update

“…It is therefore interesting to explore the complementarity with direct detection and collider experiments in searching for those models. We will here focus on one example where DM arises in a model of gauged lepton number, and where the lepton number breaking PT is the source of the GWs [190,197]. Similar studies appeared recently in [69,189].…”

“…The possibility of detecting GWs from a PT in a dark sector was explored in [180] in models of composite dark sectors, and further explored in a variety of other DM scenarios in [69,[181][182][183][184][185][186][187][188][189][190][191][192]. While of course any hidden sector could be engineered to feature a cosmological PT, scenarios in which the PT serves a specific purpose can yield specific predictions for GW signals at LISA.…”

“…The lightest new neutrino becomes the DM candidate, stabilised by a residual global symmetry that remains after gauge symmetry breaking. LEP data constrains the L-symmetry breaking scale v Φ to be above 2 TeV, putting Figure 15: Reach of LISA for gauged lepton number DM model (red shaded region), from [190].…”

Dynamical axions and gravitational waves

“…Particularly well-studied examples include the electroweak phase transition in Beyond the Standard Model (BSM) theories (for recent reviews, see [1,2]), but recently, perturbative phase transitions in hidden sectors (e.g. [3][4][5][6][7][8]), and phase transitions in GUT-theories [9,10] have also been studied.…”

Gravitational waves from scale-invariant vector dark matter model: probing below the neutrino-floor

“…Particularly, conformal DM models with Higgs portal are attractive because they can solve DM problem and at the same time can generate a strongly first order phase transition [8][9][10][11]. GWs due to first order phase transition have been studied within models where the scale-invariant symmetry is broken due to Coleman-Weinberg mechanism [12][13][14][15][16][17][18][19][20] or models with DM candidate [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39]. Conformal * a.mohamadnejad@ut.ac.ir symmetry also proposed as a possible solution for hierarchy problem [40].…”