Augury of Darkness: The Low-Mass Dark Z' Portal

• Published in: arXiv.org
• Main Authors: Alves, Alexandre, Arcadi, Giorgio, Mambrini, Yann, Profumo, Stefano, Queiroz, Farinaldo S
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 22.12.2016
• Subjects: Bosons; Cornering; Couplings; Dark matter; Darkness; Fermions; Gamma rays; Large Hadron Collider; Nuclear energy; Nuclear engineering; Nuclear reactors; Physics - High Energy Astrophysical Phenomena; Physics - High Energy Physics - Experiment; Physics - High Energy Physics - Phenomenology; Scattering; Searching
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1612.07282

Dirac fermion dark matter models with heavy \(Z^{\prime}\) mediators are subject to stringent constraints from spin-independent direct searches and from LHC bounds, cornering them to live near the \(Z^{\prime}\) resonance. Such constraints can be relaxed, however, by turning off the vector coupling to Standard Model fermions, thus weakening direct detection bounds, or by resorting to light \(Z^{\prime}\) masses, below the Z pole, to escape heavy resonance searches at the LHC. In this work we investigate both cases, as well as the applicability of our findings to Majorana dark matter. We derive collider bounds for light \(Z^{\prime}\) gauge bosons using the \(CL_S\) method, spin-dependent scattering limits, as well as the spin-independent scattering rate arising from the evolution of couplings between the energy scale of the mediator mass and the nuclear energy scale, and indirect detection limits. We show that such scenarios are still rather constrained by data, and that near resonance they could accommodate the gamma-ray GeV excess in the Galactic center.