Abstract
We perform a consistent analysis of the alternative left-right symmetric model emerging from E6 grand unification. We include a large set of theoretical and experimental constraints, with a particular emphasis on dark matter observables and collider signals. We show that the exotic neutrino inherent to this class of models, the scotino, is a viable candidate for dark matter satisfying relic density and direct detection constraints. This has strong implications on the scotino mass restricting it to lie in a narrow window, as well as on the spectrum of Higgs bosons, rendering it predictable, with a few light scalar, pseudoscalar and charged states. Moreover, we also show that the extra charged W′ gauge boson can be light, and investigate the most promising signals at the future high-luminosity upgrade of the LHC. Our findings show that the most optimistic cosmologically-favoured scenarios should be observable at 5σ, whilst others could leave visible hints provided the background is under good control at the systematical level.
Highlights
Grand unification models based on the breaking of the exceptional group E6 [16, 17] have been popular for awhile, at the beginning as a result of developments in string theories [18], later as generators of models with additional U(1) symmetries [19]
In the so-called left-right symmetric model (LRSM), that naturally accounts for non-vanishing neutrino masses [20,21,22,23], SU(2)H is identified with SU(2)R and U(1)X with U(1)B−L
We have considered in this work an alternative realisation of the left-right symmetric model, the so-called alternative left-right symmetric model (ALRSM), that can be obtained from the breaking of an E6 Grand Unified setup
Summary
The alternative left-right symmetric model [25,26,27,28] is a variant of the more usual minimal left-right symmetric model. In order to recover the electroweak symmetry group, the gauge and global symmetry SU(2)R × U(1)B−L × U(1)S is first broken down to the hypercharge U(1)Y while preserving the generalised lepton number L. This is achieved through an SU(2)R doublet of scalar fields χR charged under U(1)S. The breaking of the left-right symmetry generates masses for the model gauge bosons and induces their mixing (from the Higgs-boson kinetic terms). We refer to appendix B for additional details on the generation of the fermion masses, and their explicit expression in terms of the other model free parameters. Where Gaμν and Fμν respectively denote the gluon and photon field strength tensors
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
