The physics of heavyZ′gauge bosons

Abstract

The U (1) ′ symmetry associated with a possible heavy Z ′ would have profound implications for particle physics and cosmology. The motivations for such particles in various extensions of the standard model, possible ranges for their masses and couplings, and classes of anomaly-free models are discussed. Present limits from electroweak and collider experiments are briefly surveyed, as are prospects for discovery and diagnostic study at future colliders. Implications of a Z ′ are discussed, including an extended Higgs sector, extended neutralino sector, and solution to the µ problem in supersymmetry; exotic fermions needed for anomaly cancellation; possible flavor changing neutral current effects; neutrino mass; possible Z ′ mediation of supersymmetry breaking; and cosmological implications for cold dark matter and electroweak baryogenesis.

LHC signatures of the constrained exceptional supersymmetric standard model

“…Fig. 1 (middle frame) indeed shows 7 We have three generations of the exotic quarks but only two of inert Higgs. For convenience, in the legends of the plots we only refer to the former.…”

LHC signatures of a Z ′ mediator between dark matter and the SU(3) sector

“…Note that we will work in what follows in the unitary gauge, where the axionic field θ X can be set to zero. 1 As far as constraints coming from dark matter are concerned, we will see in the next sections that the study of [11] provides stringent constraints on the coupling d g /M 2 for low masses of the Z using an analysis of the monojets + missing E T at the LHC (8 TeV). Such constraints will be only mentioned in the following study as a possible restriction of the results, since the presence of a gluophilic Z does not necessarily implies the presence of a dark sector -nor constitutes the exclusive possibility of interaction of DM with the SM.…”

“…One of the most simple extension of the Standard Model (SM) is to provide the latter an additional U(1) abelian symmetry [1,2]. The associated gauge boson -usually denoted by Z in the literature -has been given a particular attention in the last decades in particular as a potential candidate for mediating interaction between the dark sector and our visible world .…”

Exotic Physics at ATLAS

“…This search benefits greatly from the reconstruction and identification of electrons and muons using the full detector information. The absence of any deviations from the background expectations make it possible to set 95% confidence level upper limits on cross section times branching ratio for a sequential standard model Z boson [20], with a lower bound on the Z mass of 2.86 TeV. A limit is also set on a spin-2 Randall-Sundrum graviton (G * ) [21], with a lower bound on the G * mass of 2.47 TeV.…”