Weakly-interacting massive particles in non-supersymmetric SO(10) grand unified models

Abstract

Non-supersymmetric SO(10) grand unified theories provide a framework in which the stability of dark matter is explained while gauge coupling unification is realized. In this work, we systematically study this possibility by classifying weakly interacting dark matter candidates in terms of their quantum numbers of SU(2) L ⊗ U(1) Y , B − L, and SU(2) R . We consider both scalar and fermion candidates. We show that the requirement of a sufficiently high unification scale to ensure a proton lifetime compatible with experimental constraints plays a strong role in selecting viable candidates. Among the scalar candidates originating from either a 16 or 144 of SO(10), only SU(2) L singlets with zero hypercharge or doublets with Y = 1/2 satisfy all constraints for SU(4) C ⊗ SU(2) L ⊗ SU(2) R and SU(3) C ⊗ SU(2) L ⊗ SU(2) R ⊗ U(1) B−L intermediate scale gauge groups. Among fermion triplets with zero hypercharge, only a triplet in the 45 with intermediate group SU(4) C ⊗ SU(2) L ⊗ SU(2) R leads to solutions with M GUT > M int and a long proton lifetime. We find three models with weak doublets and Y = 1/2 as dark matter candidates for the SU(4) C ⊗ SU(2) L ⊗ SU(2) R and SU(4) C ⊗ SU(2) L ⊗ U(1) R intermediate scale gauge groups assuming a minimal Higgs content. We also discuss how these models may be tested at accelerators and in dark matter detection experiments.

Dark matter in E6 Grand unification

“…This discrete symmetry can arise naturally when a gauge symmetry is spontaneously broken [17][18][19][20][21]. The idea of a discrete remnant symmetry has been recently incorporated in SO(10) GUT models [22][23][24]. We show that the stability of the lightest exotic E 6 fermion can be guaranteed by a remnant discrete symmetry, which is therefore an ideal dark matter candidate.…”

Axion predictions in SO(10) × U(1)PQ models

“…Similar to Model 2.1, this model allows for axions in the post-inflationary DM window. Remarkably, the model features a second potential DM candidate: the lightest stable combination of the additional fermions [93][94][95][96]. Therefore we do not need to insist on the axion being 100% of the observed dark matter and can allow for bigger axion masses (cf.…”

The ATLAS diboson resonance in non-supersymmetric SO(10)

“…The dark matter candidate is stabilized by a residual Z 2 symmetry arising after the SO(10) symmetry has been completely broken to the SM gauge symmetries [47][48][49][50][51][52][53][54][55][56][57][58][59]. This residual Z 2 , as it turns out, is equivalent to matter parity [60][61][62][63][64].…”

“…This model is obtained in a similar manner to that discussed in ref. [57], except now we allow for two intermediate scales. To obtain these intermediate scales, we need to arrange some Higgs fields to acquire vacuum expectation values (VEVs) in specific directions at particular scales.…”

“…For a detailed discussions on this class of dark matter candidates in SO(10) GUTs, see refs. [56,57]. The low-energy matter content of this model, beyond the SM fermions and righthanded neutrinos (which are embedded into three 16 representations), is given in table 1.…”