We discuss the predictions of a constrained version of the exceptional
supersymmetric standard model (cE6SSM), with a universal high energy soft
scalar mass, soft trilinear coupling and soft gaugino mass. The spectrum
includes a light gluino, a light wino-like neutralino and chargino pair and a
light bino-like neutralino, with other sparticle masses except the lighter stop
being much heavier. We also discuss scenarios with an extra light exotic colour
triplet of fermions and scalars and a TeV scale Z', which lead to early exotic
physics signals at the LHC.Comment: To appear in proceedings of The 2009 Europhysics Conference on High
  Energy Physics, 16-22 July 2009 Krakow, Poland; 4 page

David J. Miller

Peter Athron

Roman Nevzorov

Stefano Moretti

Steve F. King

English

arXiv

We discuss the predictions of a constrained version of the exceptional supersymmetric standard model (cE6SSM), with a universal high energy soft scalar mass, soft trilinear coupling and soft gaugino mass. The spectrum includes a light gluino, a light wino-like neutralino and chargino pair and a light bino-like neutralino, with other sparticle masses except the lighter stop being much heavier. We also discuss scenarios with an extra light exotic colour triplet of fermions and scalars and a TeV scale Z', which lead to early exotic physics signals at the LHC

Athron, Peter

King, Stephen F.

Miller, David J.

Moretti, Stefano

Nevzorov, Roman

Southampton (e-Prints Soton)

The constrained E6SSM

Enlighten

PoS(EPS-HEP 2009)249The Constrained E6SSMPeter ATHRONInstitut für Kern- und Teilchenphysik, TU Dresden, D-01062, GermanyE-mail: p.athron@physik.tu-dresden.deStephen F. KINGSchool of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, U.K.E-mail: sfk@hep.phys.soton.ac.ukDavid J. MILLER∗Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.E-mail: d.miller@physics.gla.ac.ukStefano MORETTISchool of Physics and Astronomy, University of Southampton, Southampton, SO17 1BJ, U.K.andDipartimento di Fisica Teorica, Università di Torino, Via Pietro Giuria 1, 10125 Torino, Italy.E-mail: stefano@phys.soton.ac.ukRoman NEVZOROV †Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.E-mail: r.nevzorov@physics.gla.ac.ukWe discuss the predictions of a constrained version of the exceptional supersymmetric standardmodel (cE6SSM), with a universal high energy soft scalar mass, soft trilinear coupling and softgaugino mass. The spectrum includes a light gluino, a light wino-like neutralino and chargino pairand a light bino-like neutralino, with other sparticle masses except the lighter stop being muchheavier. We also discuss scenarios with an extra light exotic colour triplet of fermions and scalarsand a TeV scale Z′, which lead to early exotic physics signals at the LHC.European Physical Society Europhysics Conference on High Energy PhysicsJuly 16-22, 2009Krakow, Poland∗Speaker.†On leave of absence from the Theory Department, ITEP, Moscow, Russiac© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence. http://pos.sissa.it/PoS(EPS-HEP 2009)249The Constrained E6SSM David J. MILLERThe Exceptional Supersymmetric Standard Model (E6SSM) [1] is inspired by Grand Unifi-cation under the gauge group E6. It does not contain the E6 symmetry, but supposes a breakingE6 → SO(10)×U(1)ψ , followed by SO(10) → SU(5)×U(1)χ , to give the subgroup SU(3)C ×SU(2)L×U(1)Y ×U(1)′ at low energies. To allow heavy right-handed neutrinos (facilitating thesee-saw mechanism), the remaining U(1)′ at low energy is the combination U(1)′ = U(1)χ cosθ +U(1)ψ sin θ with θ = arctan√15, which keeps the right-handed neutrinos sterile.The particle content forms a complete 27 representation of E6 for each generation, cancellinganomalies automatically. The 27i decomposes under the SU(5)×U(1)N subgroup of E6 as27i → (10, 1)i +(5∗, 2)i +(5∗,−3)i +(5,−2)i +(1,5)i +(1,0)i , (1)where bracketed quantities are the SU(5) representation and U(1)N charge (×√40) with i a familyindex. Ordinary SM quarks and leptons are assigned to (10,1)i +(5∗, 2)i, right-handed neutrinosNci appear in (1,0)i, and (1,5)i provides singlet fields (Si) that carry non-zero U(1)N charges andsurvive down to the EW scale. There are three pairs of SU(2)-doublets (Hdi and Hui ) in (5∗,−3)iand we identify the third generation with the MSSM Higgs doublets; the other two do not get VEVsand we refer to them as “inert”. These multiplets also contain colour triplets of exotic quarks (Diand Di). The model also requires superfields H ′ and H ′ from extra incomplete representations toensure gauge coupling unification (see Ref. [2] for an alternate unification scenario).Extra symmetries are required to prevent unwanted flavour changing neutral currents and pro-ton decay. To suppress flavour changing neutral currents, one postulates a ZH2 symmetry underwhich all superfields except the third generation Higgs fields are odd. This can only be an approx-imate symmetry, otherwise the exotics would not be able to decay. To prevent rapid proton decay,a generalisation of R-parity is imposed. If the Higgs, exotic quarks and quark superfields are evenunder a discrete ZL2 symmetry while the lepton superfields are odd, we will call this Model I and thesuperpotential is invariant with respect to a U(1)B global symmetry. The exotic Di and Di are thenidentified as diquark and anti-diquark, i.e. BD = −2/3 and BD = 2/3. Alternatively (model II),the exotic quarks and the lepton superfields could be odd under ZB2 whereas the others superfieldsremain even. In this case the Di and Di are leptoquarks.Integrating out the heavy right-handed neutrinos, and assuming a hierarchical structure ofYukawas, the superpotential becomes approximately,WE6SSM ≃ λiS3(Hdi Hui )+ κiS3(DiDi)+ ht(Hu3 Q)tc + hb(Hd3 Q)bc + hτ(Hd3 L)τc + µ ′(H′H ′), (2)where i = 1,2,3 and λi, κi are dimensionless couplings. The above ignores small ZH2 violatingterms such as gi jkDi (Q jQk) which are unimportant for production, but may be important for decay.The E6SSM has 43 new parameters (14 of which are phases) compared to the MSSM, so it isuseful to consider a constrained model, where the parameters unify at the GUT scale, MX . In theconstrained E6SSM (cE6SSM), soft scalar masses are set to m0, gaugino masses are set to M1/2and trilinear scalar couplings are set to A0, at the scale MX [3, 4]. It is thus characterised by theparameters λi(MX), κi(MX), ht(MX), hb(MX), hτ (MX), m0, M1/2 and A0.To calculate the low energy spectrum, we derived two-loop renormalisation group equations(RGEs) for gauge and Yukawa couplings, two–loop RGEs for Ma(Q) and Ai(Q) and one–loopRGEs for m2i (Q). We implemented these into a modified version of SOFTSUSY 2.0.5 [5]. The2PoS(EPS-HEP 2009)249The Constrained E6SSM David J. MILLERgauge and Yukawa couplings are independent of the soft SUSY breaking parameters so are deter-mined first. The Higgs VEVs, third generation Yukawas and gauge couplings (except g′i) are inputat the low energy scale, while κi(MX), λi(MX) are high scale inputs. We insist on gauge couplingunification, and iterate until everything is consistent. The low energy SUSY breaking parametersare determined semi-analytically as (linear or quadratic) functions of A0, M1/2 and m0. The coeffi-cients of each term are unknown analytically but are determined numerically. We obtain values form0, M1/2 and A0 that are consistent with EWSB by imposing minimisation conditions on the one-loop effective Higgs potential (obtaining up to four solutions for each set of Yukawa couplings),and then calculate the mass spectrum. Although correct EWSB is not guaranteed, there are alwayssolutions with real A0, M1/2 and m0 for sufficiently large κi. κi couples the singlet to a large numberof coloured fields, efficiently driving its squared mass negative to trigger symmetry breaking.To avoid conflict with experiment we impose: mh≥ 114 GeV; sleptons and charginos are heav-ier than 100GeV; squarks and gluinos have masses above 300GeV and the Z′ boson has a masslarger than 861GeV. We also impose bounds on the exotic quarks and squarks from the HERAexperiments, by requiring them to be heavier than 300GeV. We require the inert Higgs and inertHiggsinos are heavier than 100 GeV due to LEP bounds. Finally, we impose some theoreticalconstraints: the lightest SUSY particle (LSP) should be a neutralino and we restrict the GUT scaleYukawa couplings to be less than 3 to ensure applicability of perturbation theory.To investigate the phenomenology, we fixed values of tanβ = 3, 10, 30 and scanned overs, κ , λ , determining values of the soft mass parameters A0, M1/2 and m0 consistent with the correctbreakdown of electroweak symmetry. We found that m0 > M1/2 for each value of s and also thatlower M1/2 is weakly correlated with lower s and thus lower Z′ masses. The low energy gauginomasses are driven by RG running to be small, so the lightest SUSY states are generally a lightgluino of mass ∼ M3, a light wino-like neutralino and chargino pair of mass ∼ M2, and a lightbino-like neutralino of mass ∼ M1, which are typically all much lighter than the Higgsino massesof order µ = λ 〈S3〉. The squarks and sleptons are much heavier than these light gauginos.We show two possible particle spectra in Fig. 1 (see Ref. [3] for the explicit parameters used).The light gauginos ensure that pair production of χ02 χ02 , χ02 χ±1 , χ±1 χ∓1 and g˜g˜ should always beFigure 1: Spectra for two cE6SSM scenarios. For explicit parameters, see Ref.[3]3PoS(EPS-HEP 2009)249The Constrained E6SSM David J. MILLERpossible at the LHC. The gluinos are relatively narrow states with width ∝ M5g˜/m4q˜, and decay viag˜→ qq˜∗→ qq¯+ EmissT , resulting in an enhancement of the cross section pp→ qq¯qq¯ + EmissT + X .For the left-hand scenario, we have taken κ1 = κ2 = κ3 at the GUT scale and large enough totrigger EWSB, resulting in heavy and degenerate exotic quarks. Nevertheless, due to mixing, wefind a light exotic coloured scalar with mass 393GeV. For the right-hand scenario, we have insteadset κ3 ≫ κ1,2, allowing for rather light exotic quarks of 391GeV.Assuming Di and Di couple most strongly to the third generation, the lightest Di and Didecay into t˜b, t ˜b, ¯t˜ ¯b, ¯t ¯˜b (if diquarks) or t˜τ , tτ˜ , ˜bντ , bν˜τ (if leptoquarks). This leads to a sub-stantial enhancement of either pp → t ¯tb¯b + EmissT + X (if diquarks) or pp → t ¯tττ¯ + EmissT + X orpp → b¯b + EmissT + X (if leptoquarks). Therefore light leptoquarks should produce a strong sig-nal with low SM background at the LHC. For example, for a D mass of 400GeV, the productioncross-section pp → D ¯D is 17.4pb. The observation of the D fermions should be possible if theyhave masses below about 1.5-2 TeV [1]. The exotic scalars ( ˜Di and ˜Di) may be produced singlyand decay into quark–quark (if diquarks) or quark–lepton (if leptoquarks) without missing energy.Recent Tevatron searches for dijet resonances rule out scalar diquarks with mass less than 630GeV.However, scalar leptoquarks may be as light as 300GeV since they are pair produced through gluonfusion. They then decay, e.g. ˜D→ tτ , leading to an enhancement of pp→ t ¯tττ¯ .A light inert Higgs decays via terms analogous to the Yukawa interactions of normal Higgssuperfields, leading to decays such as H01, i → b¯b and H−1, i → τ ¯ντ . Similar couplings govern inertHiggsino decays resulting in e.g. ˜H0i → t˜¯t∗, ˜H0i → τ ˜τ¯∗, ˜H+i → t ˜¯b∗and ˜H−i → τ ˜¯ν∗τ .To conclude, the cE6SSM is a well motivated model with a distinctive spectrum: a light gluino(much lighter than the squarks), and new exotic states such as a Z′ and colour triplet fermions andscalars. If these new states are light enough, they could be found with early LHC data, leading toa revolution in particle physics, and pointing towards an underlying high energy E6 gauge structure.Acknowledgements: DJM acknowledges support from the STFC Advanced Fellowship GrantPP/C502722/1. RN acknowledges support from the SHEFC grant HR03020 SUPA 36878. SFKacknowledges partial support from: STFC Rolling Grant ST/G000557/1 (also SM); EU NetworkMRTN-CT-2004-503369; NATO grant PST.CLG.980066 (also SM); EU ILIAS RII3-CT-2004-506222. SM is also supported in part by the FP7 RTN MRTN-CT-2006-035505, and the scheme“Visiting Professor - Azione D - Atto Integrativo tra la Regione Piemonte e gli Atenei Piemontesi”.References[1] S. F. King, S. Moretti, R. Nevzorov, Phys. Rev. D 73 (2006) 035009; Phys. Lett. B 634 (2006) 278;Phys. Lett. B 650 (2007) 57.[2] R. Howl and S. F. King, JHEP 0805 (2008) 008 [arXiv:0802.1909 [hep-ph]]; JHEP 0801 (2008) 030[arXiv:0708.1451 [hep-ph]]; Phys. Lett. B 652 (2007) 331 [arXiv:0705.0301 [hep-ph]].[3] P. Athron, S. F. King, D. J. . Miller, S. Moretti and R. Nevzorov, arXiv:0901.1192 [hep-ph].[4] P. Athron, S. F. King, D. J. Miller, S. Moretti and R. Nevzorov, Phys. Rev. D 80 (2009) 035009[arXiv:0904.2169 [hep-ph]].[5] B. C. Allanach, Comput. Phys. Commun. 143 (2002) 305.4

The constrained E(6)SSM

We discuss the predictions of a constrained version of the exceptional supersymmetric standard model (cE6SSM), with a universal high energy soft scalar mass, soft trilinear coupling and soft gaugino mass. The spectrum includes a light gluino, a light wino-like neutralino and chargino pair and a light bino-like neutralino, with other sparticle mass es except the lighter stop being much heavier. We also discuss scenarios with an extra light exotic colour triplet of fermions and scalars and a TeV scale Z ′ , which lead to early exotic physics signals at the LHC

Open Access Repository

PoS(EPS-HEP 2009)249The Constrained E6SSMPeter ATHRONInstitut für Kern- und Teilchenphysik, TU Dresden, D-01062, GermanyE-mail: p.athron@physik.tu-dresden.deStephen F. KINGSchool of Physics and Astronomy, University of Southampton, S uthampton, SO17 1BJ, U.K.E-mail: sfk@hep.phys.soton.ac.ukDavid J. MILLER∗Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.E-mail: d.miller@physics.gla.ac.ukStefano MORETTISchool of Physics and Astronomy, University of Southampton, S uthampton, SO17 1BJ, U.K.andDipartimento di Fisica Teorica, Università di Torino, Via Pietro Giuria 1, 10125 Torino, Italy.E-mail: stefano@phys.soton.ac.ukRoman NEVZOROV †Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, U.K.E-mail: r.nevzorov@physics.gla.ac.ukWe discuss the predictions of a constrained version of the exc ptional supersymmetric standardmodel (cE6SSM), with a universal high energy soft scalar mass, soft trilinear coupling and softgaugino mass. The spectrum includes a light gluino, a light wino-like neutralino and chargino pairand a light bino-like neutralino, with other sparticle masses except the lighter stop being muchheavier. We also discuss scenarios with an extra light exotic c lour triplet of fermions and scalarsand a TeV scaleZ′, which lead to early exotic physics signals at the LHC.European Physical Society Europhysics Conference on High Energy PhysicsJuly 16-22, 2009Krakow, Poland∗Speaker.†On leave of absence from the Theory Department, ITEP, Moscow, Russiac© Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licen. http://pos.sissa.it/PoS(EPS-HEP 2009)249The Constrained E6SSM David J. MILLERThe Exceptional Supersymmetric Standard Model (E6SSM) [1] is inspired by Grand Unifi-cation under the gauge groupE6. It does not contain theE6 symmetry, but supposes a breakingE6 → SO(10)×U(1)ψ , followed bySO(10) → SU(5)×U(1)χ , to give the subgroupSU(3)C ×SU(2)L ×U(1)Y ×U(1)′ at low energies. To allow heavy right-handed neutrinos (facilit ting thesee-saw mechanism), the remainingU(1)′ at low energy is the combinationU(1)′ =U(1)χ cosθ +U(1)ψ sinθ with θ = arctan√15, which keeps the right-handed neutrinos sterile.The particle content forms a complete 27 representation ofE6 for each generation, cancellinganomalies automatically. The 27i decomposes under theSU(5)×U(1)N subgroup ofE6 as27i → (10, 1)i +(5∗, 2)i +(5∗, −3)i +(5,−2)i +(1,5)i +(1,0)i , (1)where bracketed quantities are theSU(5) representation andU(1)N charge (×√40) with i a familyindex. Ordinary SM quarks and leptons are assigned to(10,1)i +(5∗, 2)i, right-handed neutrinosNci appear in(1,0)i, and(1,5)i provides singlet fields (Si ) that carry non-zeroU(1)N charges andsurvive down to the EW scale. There are three pairs ofSU(2)-doublets (Hdi andHui ) in (5∗, −3)iand we identify the third generation with the MSSM Higgs doublets; the other two do not get VEVsand we refer to them as “inert”. These multiplets also contain colour triplets of exotic quarks (DiandDi). The model also requires superfieldsH ′ andH′from extra incomplete representations toensure gauge coupling unification (see Ref. [2] for an alternat unification scenario).Extra symmetries are required to prevent unwanted flavour changing neutral currents and pro-ton decay. To suppress flavour changing neutral currents, one p stulates aZH2 symmetry underwhich all superfields except the third generation Higgs fields are odd. This can only be an approx-imate symmetry, otherwise the exotics would not be able to decay. To prevent rapid proton decay,a generalisation of R-parity is imposed. If the Higgs, exotic quarks and quark superfields are evenunder a discreteZL2 symmetry while the lepton superfields are odd, we will call this Model I and thesuperpotential is invariant with respect to aU(1)B global symmetry. The exoticDi andDi are thenidentified as diquark and anti-diquark, i.e.BD = −2/3 andBD = 2/3. Alternatively (model II),the exotic quarks and the lepton superfields could be odd under ZB2 whereas the others superfieldsremain even. In this case theDi andDi are leptoquarks.Integrating out the heavy right-handed neutrinos, and assuming a hierarchical structure ofYukawas, the superpotential becomes approximately,WE6SSM≃ λiS3(Hdi Hui )+ κiS3(DiDi)+ht(Hu3Q)tc +hb(Hd3 Q)bc +hτ(Hd3 L)τc + µ ′(H′H ′), (2)where i = 1,2,3 andλi, κi are dimensionless couplings. The above ignores smallZH2 violatingterms such asgi jkDi (Q jQk) which are unimportant for production, but may be important for decay.The E6SSM has 43 new parameters (14 of which are phases) compared tothe MSSM, so it isuseful to consider a constrained model, where the parameters unify at the GUT scale,MX. In theconstrained E6SSM (cE6SSM), soft scalar masses are set tom0, gaugino masses are set toM1/2and trilinear scalar couplings are set toA0, at the scaleMX [3, 4]. It is thus characterised by theparametersλi(MX), κi(MX), ht(MX), hb(MX), hτ (MX), m0, M1/2 andA0.To calculate the low energy spectrum, we derived two-loop renormalisation group equations(RGEs) for gauge and Yukawa couplings, two–loop RGEs forMa(Q) and Ai(Q) and one–loopRGEs form2i (Q). We implemented these into a modified version of SOFTSUSY 2.0.5 [5]. The2PoS(EPS-HEP 2009)249The Constrained E6SSM David J. MILLERgauge and Yukawa couplings are independent of the soft SUSY breaking parameters so are deter-mined first. The Higgs VEVs, third generation Yukawas and gauge couplings (exceptg′i ) are inputat the low energy scale, whileκi(MX), λi(MX) are high scale inputs. We insist on gauge couplingunification, and iterate until everything is consistent. The low energy SUSY breaking parametersare determined semi-analytically as (linear or quadratic)functions ofA0, M1/2 andm0. The coeffi-cients of each term are unknown analytically but are determined numerically. We obtain values form0, M1/2 andA0 that are consistent with EWSB by imposing minimisation conditions on the one-loop effective Higgs potential (obtaining up to four solutions for each set of Yukawa couplings),and then calculate the mass spectrum. Although correct EWSBis not guaranteed, there are alwayssolutions with realA0, M1/2 andm0 for sufficiently largeκi . κi couples the singlet to a large numberof coloured fields, efficiently driving its squared mass negative to trigger symmetry breaking.To avoid conflict with experiment we impose:mh ≥ 114 GeV; sleptons and charginos are heav-ier than 100GeV; squarks and gluinos have masses above 300GeV and theZ′ boson has a masslarger than 861GeV. We also impose bounds on the exotic quarks and squarks from the HERAexperiments, by requiring them to be heavier than 300GeV. Werequire the inert Higgs and inertHiggsinos are heavier than 100 GeV due to LEP bounds. Finally, we impose some theoreticalconstraints: the lightest SUSY particle (LSP) should be a neutralino and we restrict the GUT scaleYukawa couplings to be less than 3 to ensure applicability ofperturbation theory.To investigate the phenomenology, we fixed values of tanβ = 3, 10, 30 and scanned overs, κ , λ , determining values of the soft mass parametersA0, M1/2 andm0 consistent with the correctbreakdown of electroweak symmetry. We found thatm0 > M1/2 for each value ofs and also thatlower M1/2 is weakly correlated with lowers and thus lowerZ′ masses. The low energy gauginomasses are driven by RG running to be small, so the lightest SUSY states are generally a lightgluino of mass∼ M3, a light wino-like neutralino and chargino pair of mass∼ M2, and a lightbino-like neutralino of mass∼ M1, which are typically all much lighter than the Higgsino massesof orderµ = λ 〈S3〉. The squarks and sleptons are much heavier than these light gauginos.We show two possible particle spectra in Fig. 1 (see Ref. [3] for the explicit parameters used).The light gauginos ensure that pair production ofχ02χ02 , χ02χ±1 , χ±1 χ∓1 and g̃g̃ should always beFigure 1: Spectra for two cE6SSM scenarios. For explicit parameters, see Ref.[3]3PoS(EPS-HEP 2009)249The Constrained E6SSM David J. MILLERpossible at the LHC. The gluinos are relatively narrow statewith width∝ M5g̃/m4q̃, and decay viag̃→ qq̃∗ → qq̄+EmissT , resulting in an enhancement of the cross sectionpp→ qq̄qq̄+EmissT +X.For the left-hand scenario, we have takenκ1 = κ2 = κ3 at the GUT scale and large enough totrigger EWSB, resulting in heavy and degenerate exotic quarks. Nevertheless, due to mixing, wefind a light exotic coloured scalar with mass 393GeV. For the right-hand scenario, we have insteadsetκ3 ≫ κ1,2, allowing for rather light exotic quarks of 391GeV.AssumingDi and Di couple most strongly to the third generation, the lightestDi and Didecay intot̃b, tb̃, ¯̃tb̄, t̄ ¯̃b (if diquarks) or t̃τ , tτ̃ , b̃ντ , bν̃τ (if leptoquarks). This leads to a sub-stantial enhancement of eitherpp→ tt̄bb̄+ EmissT + X (if diquarks) orpp→ tt̄ττ̄ + EmissT + X orpp→ bb̄+ EmissT + X (if leptoquarks). Therefore light leptoquarks should produce a strong sig-nal with low SM background at the LHC. For example, for aD mass of 400GeV, the productioncross-sectionpp→ DD̄ is 17.4pb. The observation of the D fermions should be possible if theyhave masses below about 1.5-2 TeV [1]. The exotic scalars (D̃i andD̃i) may be produced singlyand decay into quark–quark (if diquarks) or quark–lepton (if leptoquarks) without missing energy.Recent Tevatron searches for dijet resonances rule out scalar diquarks with mass less than 630GeV.However, scalar leptoquarks may be as light as 300GeV since they are pair produced through gluonfusion. They then decay, e.g.D̃ → tτ , leading to an enhancement ofpp→ tt̄ττ̄.A light inert Higgs decays via terms analogous to the Yukawa interactions of normal Higgssuperfields, leading to decays such asH01, i → bb̄ andH−1, i → τν̄τ . Similar couplings govern inertHiggsino decays resulting in e.g.H̃0i → t ˜̄t∗, H̃0i → τ ˜̄τ∗, H̃+i → t ˜̄b∗andH̃−i → τ ˜̄ν∗τ .To conclude, the cE6SSM is a well motivated model with a distinctive spectrum: a light gluino(much lighter than the squarks), and new exotic states such as aZ′ and colour triplet fermions andscalars. If these new states are light enough, they could be found with early LHC data, leading toa revolution in particle physics, and pointing towards an underlying high energyE6 gauge structure.Acknowledgements: DJM acknowledges support from the STFC Advanced FellowshipGrantPP/C502722/1. RN acknowledges support from the SHEFC grantHR03020 SUPA 36878. SFKacknowledges partial support from: STFC Rolling Grant ST/G000557/1 (also SM); EU NetworkMRTN-CT-2004-503369; NATO grant PST.CLG.980066 (also SM); EU ILIAS RII3-CT-2004-506222. SM is also supported in part by the FP7 RTN MRTN-CT-2006- 35505, and the scheme“Visiting Professor - Azione D - Atto Integrativo tra la Regione Piemonte e gli Atenei Piemontesi”.References[1] S. F. King, S. Moretti, R. Nevzorov, Phys. Rev. D73 (2006) 035009; Phys. Lett. B634 (2006) 278;Phys. Lett. B650 (2007) 57.[2] R. Howl and S. F. King, JHEP0805 (2008) 008 [arXiv:0802.1909 [hep-ph]]; JHEP0801 (2008) 030[arXiv:0708.1451 [hep-ph]]; Phys. Lett. B652 (2007) 331 [arXiv:0705.0301 [hep-ph]].[3] P. Athron, S. F. King, D. J. . Miller, S. Moretti and R. Nevzorov, arXiv:0901.1192 [hep-ph].[4] P. Athron, S. F. King, D. J. Miller, S. Moretti and R. Nevzorov, Phys. Rev. D80 (2009) 035009[arXiv:0904.2169 [hep-ph]].[5] B. C. Allanach, Comput. Phys. Commun.143 (2002) 305.4

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The constrained E6SSM

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