Leptonic Scalars and Collider Signatures in a UV-complete Model

Abstract

We study the non-standard interactions of neutrinos with light leptonic scalars (φ) in a global (B − L)-conserved ultraviolet (UV)-complete model. The model utilizes Type-II seesaw motivated neutrino interactions with an SU (2) L -triplet scalar, along with an additional singlet in the scalar sector. This UV-completion leads to an enriched spectrum and consequently new observable signatures. We examine the low-energy lepton flavor violation constraints, as well as the perturbativity and unitarity constraints on the model parameters. Then we lay out a search strategy for the unique signature of the model resulting from the leptonic scalars at the hadron colliders via the processes H ±± → W ± W ± φ and H ± → W ± φ for both small and large leptonic Yukawa coupling cases. We find that via these associated production processes at the HL-LHC, the prospects of doubly-charged scalar H ±± can reach up to 800 (500) GeV and 1.1 (0.8) TeV at the 2σ (5σ) significance for small and large Yukawa couplings, respectively. A future 100 TeV hadron collider will further increase the mass reaches up to 3.8 (2.6) TeV and 4 (2.7) TeV, at the 2σ (5σ) significance, respectively. We also demonstrate that the mass of φ can be determined at about 10% accuracy at the LHC for the large Yukawa coupling case even though it escapes as missing energy from the detectors.

Light scalars in neutron star mergers

“…• With couplings exclusively or predominantly to some specific SM flavors, such as the hadronic and leptonic scalars [109][110][111][112].…”

Nuclear fusion catalyzed by doubly charged scalars: Implications for energy production

“…Z 2 symmetry X → −X, in which case the X-scalars will be stable. For discussions of current experimental constraints on the doubly charged particles and of the sensitivities to them of future experiments see [21][22][23][24][25][26] and references therein.…”