Theory and phenomenology of an exceptional supersymmetric standard model
Abstract
We make a comprehensive study of the theory and phenomenology of a lowenergy supersymmetric standard model originating from a stringinspired E{sub 6} grand unified gauge group. The exceptional supersymmetric standard model (ESSM) considered here is based on the lowenergy standard model gauge group together with an extra Z{sup '} corresponding to an extra U(1){sub N} gauge symmetry under which righthanded neutrinos have zero charge. The lowenergy matter content of the ESSM corresponds to three 27 representations of the E{sub 6} symmetry group, to ensure anomaly cancellation, plus an additional pair of Higgslike doublets as required for highenergy gauge coupling unification. The ESSM is therefore a lowenergy alternative to the minimal supersymmetric standard model (MSSM) or nexttominimal supersymmetric standard model (NMSSM). The ESSM involves extra matter beyond the MSSM contained in three 5+5* representations of SU(5), plus three SU(5) singlets which carry U(1){sub N} charges, one of which develops a vacuum expectation value, providing the effective {mu} term for the Higgs doublets, as well as the necessary exotic fermion masses. We explore the renormalization group flow of the ESSM and examine theoretical restrictions on the values of new Yukawa couplings caused by the validity of perturbation theory up to the grandmore »
 Authors:
 School of Physics and Astronomy, University of Southampton, Highfield, Southampton, SO17 1BJ (United Kingdom)
 Publication Date:
 OSTI Identifier:
 20776688
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. D, Particles Fields; Journal Volume: 73; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevD.73.035009; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; APPROXIMATIONS; COUPLING; EXPECTATION VALUE; GAUGE INVARIANCE; HIGGS BOSONS; HIGGS MODEL; NEUTRINOS; PERTURBATION THEORY; RENORMALIZATION; REST MASS; STANDARD MODEL; SU5 GROUPS; SUPERSYMMETRY; SYMMETRY BREAKING; UNITARY SYMMETRY
Citation Formats
King, S.F., Moretti, S., and Nevzorov, R. Theory and phenomenology of an exceptional supersymmetric standard model. United States: N. p., 2006.
Web. doi:10.1103/PhysRevD.73.035009.
King, S.F., Moretti, S., & Nevzorov, R. Theory and phenomenology of an exceptional supersymmetric standard model. United States. doi:10.1103/PhysRevD.73.035009.
King, S.F., Moretti, S., and Nevzorov, R. Wed .
"Theory and phenomenology of an exceptional supersymmetric standard model". United States.
doi:10.1103/PhysRevD.73.035009.
@article{osti_20776688,
title = {Theory and phenomenology of an exceptional supersymmetric standard model},
author = {King, S.F. and Moretti, S. and Nevzorov, R.},
abstractNote = {We make a comprehensive study of the theory and phenomenology of a lowenergy supersymmetric standard model originating from a stringinspired E{sub 6} grand unified gauge group. The exceptional supersymmetric standard model (ESSM) considered here is based on the lowenergy standard model gauge group together with an extra Z{sup '} corresponding to an extra U(1){sub N} gauge symmetry under which righthanded neutrinos have zero charge. The lowenergy matter content of the ESSM corresponds to three 27 representations of the E{sub 6} symmetry group, to ensure anomaly cancellation, plus an additional pair of Higgslike doublets as required for highenergy gauge coupling unification. The ESSM is therefore a lowenergy alternative to the minimal supersymmetric standard model (MSSM) or nexttominimal supersymmetric standard model (NMSSM). The ESSM involves extra matter beyond the MSSM contained in three 5+5* representations of SU(5), plus three SU(5) singlets which carry U(1){sub N} charges, one of which develops a vacuum expectation value, providing the effective {mu} term for the Higgs doublets, as well as the necessary exotic fermion masses. We explore the renormalization group flow of the ESSM and examine theoretical restrictions on the values of new Yukawa couplings caused by the validity of perturbation theory up to the grand unification scale. We then discuss electroweak symmetry breaking and Higgs phenomenology and establish an upper limit on the mass of the lightest Higgs particle which can be significantly heavier than in the MSSM and NMSSM, in leading twoloop approximation. We also discuss the phenomenology of the Z{sup '} and the extra matter, whose discovery will provide a smoking gun signal of the model.},
doi = {10.1103/PhysRevD.73.035009},
journal = {Physical Review. D, Particles Fields},
number = 3,
volume = 73,
place = {United States},
year = {Wed Feb 01 00:00:00 EST 2006},
month = {Wed Feb 01 00:00:00 EST 2006}
}

We propose and study a constrained version of the exceptional supersymmetric standard model (E{sub 6}SSM), which we call the cE{sub 6}SSM, based on a universal high energy scalar mass m{sub 0}, trilinear scalar coupling A{sub 0} and gaugino mass M{sub 1/2}. We derive the renormalization group (RG) Equations for the cE{sub 6}SSM, including the extra U(1){sub N} gauge factor and the lowenergy matter content involving three 27 representations of E{sub 6}. We perform a numerical RG analysis for the cE{sub 6}SSM, imposing the usual lowenergy experimental constraints and successful electroweak symmetry breaking. Our analysis reveals that the sparticle spectrum ofmore »

Phenomenological Consequences of the Constrained Exceptional Supersymmetric Standard Model
The Exceptional Supersymmetric Standard Model (E{sub 6}SSM) provides a low energy alternative to the MSSM, with an extra gauged U(1){sub N} symmetry, solving the muproblem of the MSSM. Inspired by the possible embedding into an E{sub 6} GUT, the matter content fills three generations of E{sub 6} multiplets, thus predicting exciting exotic matter such as diquarks or leptoquarks. We present predictions from a constrained version of the model (cE{sub 6}SSM), with a universal scalar mass m{sub 0}, trilinear mass A and gaugino mass M{sub 1/2}. We reveal a large volume of the cE{sub 6}SSM parameter space where the correct breakdownmore » 
Novel Higgs decays and dark matter in the exceptional supersymmetric standard model
The Exceptional Supersymmetric (SUSY) Standard Model (E{sub 6}SSM) predicts three families of Higgs doublets plus three Higgs singlets, where one family develops vacuum expectation values (VEVs), while the remaining two which do not are called Inert. The model can account for the dark matter relic abundance if the two lightest Inert neutralinos, identified as the (nextto) lightest SUSY particles ((N)LSPs), have masses close to half the Z mass. In this case we find that the usual SMlike Higgs boson decays more than 95% of the time into either LSPs or NLSPs. The latter case produces a final state containing twomore » 
Electroweak baryogenesis in the exceptional supersymmetric standard model
We study electroweak baryogenesis in the E{sub 6} inspired exceptional supersymmetric standard model (E{sub 6}SSM). The relaxation coefficients driven by singlinos and the new gaugino as well as the transport equation of the Higgs supermultiplet number density in the E{sub 6}SSM are calculated. Our numerical simulation shows that both CPviolating source terms from singlinos and the new gaugino can solely give rise to a correct baryon asymmetry of the Universe via the electroweak baryogenesis mechanism. 
Electroweak baryogenesis in the exceptional supersymmetric standard model
We study electroweak baryogenesis in the E{sub 6} inspired exceptional supersymmetric standard model (E{sub 6}SSM). The relaxation coefficients driven by singlinos and the new gaugino as well as the transport equation of the Higgs supermultiplet number density in the E{sub 6}SSM are calculated. Our numerical simulation shows that both CPviolating source terms from singlinos and the new gaugino can solely give rise to a correct baryon asymmetry of the Universe via the electroweak baryogenesis mechanism.