We study a gauge B–L extension of the standard model of quarks and leptons with unconventional charges for the singlet right-handed neutrinos, and extra singlet scalars, such that a residual Z3 symmetry remains after the spontaneous breaking of B–L. We discuss the phenomenological consequences of this scenario, including the possibility of long-lived self-interacting dark matter and Z′ collider signatures

The neutron lifetime anomaly has been used to motivate the introduction of new physics with hidden-sector particles coupled to baryon number, and on which neutron stars provide powerful constraints. Although the neutron lifetime anomaly may eventually prove to be of mundane origin, we use it as motivation for a broader review of the ways that baryon number violation, be it real or apparent, and dark sectors can intertwine and how neutron star observables, both present and future, can constrain them.

An SU(2)_Nextension (Nstands for neutral) of the Standard Model (SM) is proposed with an additional U(1)=S′ global symmetry, which stabilizes the lightest of the vector boson (X,X̄) as dark matter (DM) through unbrokenS=T_3N+S′. The field content of the model is motivated to address neutrino mass generation, a possible unification to SU(7), along with spontaneous symmetry breaking of SU(2)_Nresulting in massive gauge bosons. None of the SM particles are charged under SU(2)_Nand thereforeX,X̄ do not have a direct coupling to the visible sector besides a Higgs portal, which is tiny to avoid any conflict with Higgs data. We show that, a large kinematic region of this model allows the neutral component of SU(2)_Nscalar triplet and heavy neutrinos introduced here to become additional DM components. In this paper we explore the viability of such multipartite DM parameter space, including non-zero DM-DM interactions, to comply with relic density and direct search constraints. We also demonstrate that the model may yield hadronically quiet single lepton and two lepton signatures with missing energy at the Large Hadron Collider (LHC) that can be accessed with high luminosity.

If the standard model of quarks and leptons is extended to include three singlet right-handed neutrinos, then the resulting fermion structure admits an infinite number of anomaly-free solutions with just one simple constraint. Well-known examples satisfying this constraint are $B-L$, $L_{\mu}-L_{\tau}$ , $B-3L_{\tau}$ , etc. We derive this simple constraint, and discuss two new examples which offer some insights to the structure of mixing among quark and lepton families, together with their possible verification at the Large Hadron Collider.Comment: 13 page