Extra $$Z^{\prime }$$ Z ′ s and $$W^{\prime }$$ W ′ s in heterotic-string derived models

Abstract

The ATLAS and CMS collaborations recently recorded possible excess in the di-boson production at the diboson invariant mass at around 2 TeV. Such an excess may be produced if there exist additional Z and/or W at that scale. We survey the extra Z s and W s that may arise from semirealistic heterotic-string vacua in the free fermionic formulation in the seven distinct cases: U (1) Z ∈ SO(10); family universal U (1) Z / ∈ SO(10); non-universal U (1) Z ; hidden sector U (1) symmetries and kinetic mixing; left-right symmetric models; Pati-Salam models; leptophobic and custodial symmetries. Each case has a distinct signature associated with the extra symmetry breaking scale. In one of the cases we explore the discovery potential at the LHC using resonant leptoproduction. The existence of an extra vector boson with the reported properties will significantly constrain the space of allowed string vacua.

LHC di-photon excess and gauge coupling unification in extra $$Z^\prime $$ Z ′ heterotic-string derived models

“…The possibility of breaking the PS symmetry at a low scale was considered in Refs. [144][145][146][147][148]. Here we will take the PS breaking scale to be in the vicinity of the string scale or slightly below.…”

“…Indeed, the presence of vector-like quarks, which is natural in heterotic-string models, facilitates the production of these states at the LHC. In the following discussion we will consider the most simple and economic scenario in order to Interestingly this can also be probed at the LHC in the lepto-production channel [148,160]. Moreover, as we have already stated, in order to reproduce the di-photon excess it is enough to consider the impact of the vector-like coloured superfields D,D only.…”

Angular observables for spin discrimination in boosted diboson final states

“…Spin-0 explanations are discussed in context of a Higgs singlet [36], a two Higgs doublet model [37][38][39][40], sparticles [41,42] or composite scalars [43,44]. Spin-1 proposals include composite vector resonances [45][46][47][48][49][50][51][52], generic and effective field theory (EFT) models [53][54][55][56] as well as heavy W resonances [22][23][24][25][57][58][59][60][61][62][63][64][65][66][67][68][69], Z resonances [26,[70][71][72][73][74][75][76] or both [77][78][79]…”

Extra Higgs boson and Z′ as portals to signatures of heavy neutrinos at the LHC

“…There are several realisations of GUTs that embed this dynamics, such as, e.g., E 6 , String Theory motivated, SO (10) and Left-Right (LR) symmetric models [1][2][3][4][5][6][7].…”