Dark matter and spin-1 milli-charged particles
Emidio Gabrielli (Università degli Studi di Trieste, Strada Costiera 11, Trieste, I-34151, Italy, INFN, Sezione di Trieste, Via Valerio 2, Trieste, I-34127, Italy, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, 12618, Estonia); Luca Marzola (National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, 12618, Estonia, University of Tartu, Institute of Physics, Ravila 14c, Tartu, 50411, Estonia); Martti Raidal (National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, 12618, Estonia, University of Tartu, Institute of Physics, Ravila 14c, Tartu, 50411, Estonia); Hardi Veermäe (National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, Tallinn, 12618, Estonia, University of Tartu, Institute of Physics, Ravila 14c, Tartu, 50411, Estonia)
New physics scenarios beyond the Standard Model predict the existence of milli-charged particles. So far, only spin-1/2 and spin-0 milli-charged particles have been considered in literature, leaving out the interesting case of spin-1. We propose a minimal unitary and renormalizable model of massive milli-charged vector particles. Unitarity requires that these particles are gauge bosons of a non-abelian spontaneously broken gauge symmetry. The minimal scenario then consists of an extended Standard Model gauge group SU(2) L × U(1) Y × SU(2) D together with a SU(2) D dark Higgs boson responsible for the symmetry breaking in the dark sector. By imposing that the dark Higgs multiplet has a non-vanishing milli-hypercharge, stable milli-charged spin-1 fields arise thereby providing a potential dark matter candidate. We analyse the phenomenological constraints on this scenario and discuss their implications.
