1 / 20

Reproducing an E 6 SSM from its Signatures

Reproducing an E 6 SSM from its Signatures. The LHC Inverse Problem:. Nima Arkani-Hamed Gordy Kane. LHC-IA - What is the new physics? LHC-IB - What is the spectrum and effective Lagrangian of the new physics at the weak scale?

solomon-rogers
Download Presentation

Reproducing an E 6 SSM from its Signatures

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Reproducing an E6SSM from its Signatures The LHC Inverse Problem: Nima Arkani-HamedGordy Kane • LHC-IA - What is the new physics? • LHC-IB - What is the spectrum and effective Lagrangian of the new physics at the weak scale? • LHC-IC - How can we begin to study what the underlying theory is, perhaps at a high scale and/or in extra dimensions? In this talk we discuss the LHC Inverse problem from the perspective of an E6 Supersymmetric Standard Model (shortly defined) Steve King, LHC Inverse Workshop, MCTP

  2. The  problem • Although MSSM solves “technical hierarchy problem” (loops) it does not address “tree-level hierarchy problem” of why Higgs masses are low • In particular no reason why  parameter (which respects SUSY) should be same order as soft masses  the “ problem”. • In M-theory this cannot be resolved a la Guidice-Masiero using the Kahler term HuHd if Hu and Hd come from 27’s of E6 since 27£ 27 is not invariant • In the NMSSM =0 but an effective -term is generated from a singlet: S Hu Hd ! <S> Hu Hd where singlet VEV <S> plays role of  parameter • A coupling S3 is required to avoid a massless axion due to global U(1) PQ symmetry which broken at weak scale. • With S3 term the symmetry is reduced to Z3 -- broken at the weak scale resulting in cosmological domain walls (or tadpoles if broken) Steve King, LHC Inverse Workshop, MCTP

  3. The E6SSM solution • We would like to solve  problem of MSSM using a singlet as in the NMSSM, but avoiding the domain wall/ tadpole problems of NMSSM • The idea is to use the superpotential coupling W= S Hu Hd (without the extra S3 term) and gauge the U(1) PQ symmetry so that the dangerous axion is eaten to form a massive Z’ gauge boson  U(1)’ model • Anomaly cancellation in low energy gauged U(1)’ models always implies either extra low energy exotic matter or family-nonuniversal U(1)’ charges • The E6SSM is an example of a U(1)’ model with extra low energy exotic matter with anomalies are cancelled elegantly using complete 27’s of E6 Steve King, LHC Inverse Workshop, MCTP

  4. E6SSM is discussed in SFK, Moretti and Nevzorov Other related references (very incomplete – apologies) Cvetic, Demir, Espinosa, Everett, Langacker; J.Wang; Keith, Ma; Daikoku, Suematsu; Demir, Everett; Hewett, Rizzo; Demir, Kane, T.Wang; Morrissey, Wells; Barger, Langacker, Lee, Shaughnessy; Steve King, LHC Inverse Workshop, MCTP

  5. MString E8£ E8! E6 MGUT E6! SU(5)£U(1)N Right handed neutrino masses Quarks, leptons Exotics and Higgs Singlets and RH s H’,H’-bar Incomplete multiplets (required for unification) TeV U(1)N broken, Z’ and exotics get mass,  term generated MW SU(2)L£ U(1)Y broken Sketch of the E6SSM Right handed neutrinos are neutral under: Steve King, LHC Inverse Workshop, MCTP

  6. Quarks and Leptons Exotic D,D-bar Higgs and non-Higgs Singlets Right-handed neutrinos Non-Higgs from incomplete reps 27’+27’-bar Low energy matter content of E6SSM Steve King, LHC Inverse Workshop, MCTP

  7. Family Universal Anomaly Free Charges: Most general E6 allowed couplings from 273: • Rapid proton decay! Need generalization of R-parity two possibilities: I. Z2L under which leptons are odd  forbids W2 exotic D,D-bar are diquarks II. Z2B with leptons & D,D-bar odd  forbids W1  exotic D,D-bar are leptoquarks Steve King, LHC Inverse Workshop, MCTP

  8. Including RH neutrino masses have two models: To suppress FCNCs we further assume an approximate Z2H symmetry under which only Hd = H1,3, Hu=H2,3 S=S3 are even (all else=odd) Suppresses W1, W2 and restricts W0 as follows (e.g. only one pair of Higgs doublets couple to quarks and leptons as in the MSSM and will get radiative VEVs): In phenomenological studies we keep only terms with large Yukawa couplings: However terms with small Yukawa couplings arising from W1 or W2. are required for exotic decays. Steve King, LHC Inverse Workshop, MCTP

  9. The origin of bilinear masses Right-handed neutrino masses arise from the coupling to the Higgs 27H which breaks E6 • We also need to generate a TeV mass term  H’ H’-bar • The simplest possibility is to use the Guidice-Masiero mechanism • The Kahler potential permits H’ H’-bar since H’ comes from 27’ and H’-bar comes from 27’-bar • Unlike Hu Hd which is forbidden since 27£ 27 is not invariant • Note that H’,H’-bar are irrelevant for Higgs phenomenology since they do not develop VEVs – they are ``non-Higgs’’ Steve King, LHC Inverse Workshop, MCTP

  10. Higgs Phenomenology of E6SSM @ LHC With Z2H only three Higgs multiplets Hu, Hd, S get VEVs W= S Hd Hd as in the NMSSM but without the S3 term (simpler!) This leads to the Higgs potential: Steve King, LHC Inverse Workshop, MCTP

  11. As in the MSSM (unlike the NMSSM since the axion is eaten by the Z’) As in the MSSM and NMSSM Extra scalar state compared to MSSM – as in the NMSSM. Can the Higgs sector of the E6SSM be distinguished from that of the MSSM and NMSSM?

  12. Small  < g1 gives an MSSM-like spectrum @ LHC (unfortunately!) Satisfies the MSSM bound singlet

  13. Large  > g1 leads to only h1 @ LHC Can exceed MSSM bound mainly singlet Too heavy to be observed @LHC

  14. E6SSM Higgs h1 mass bound SFK,Moretti,Nevzorov Observing a heavy Higgs boson @ LHC is one way (only way!) to distinguish the E6SSM from the NMSSM or MSSM Higgs sectors ESSM NMSSM MSSM 2-loop Higgs mass bounds Steve King, LHC Inverse Workshop, MCTP

  15. Z’ Phenomenology in E6SSM SFK,Moretti,Nevzorov Steve King, LHC Inverse Workshop, MCTP

  16. SFK,Moretti,Nevzorov Exotic D-quarks in E6SSM @ LHC Inv. mass distribution Total cross section Steve King, LHC Inverse Workshop, MCTP

  17. Non-Higgsino discovery difficult due to small cross-section @ LHC Steve King, LHC Inverse Workshop, MCTP

  18. Some E6SSM Challenges for the LHC Inverse Problem • Discover: • the Z’, SUSY, the Higgs, the exotic D-quarks, the non-Higginos (Pythia needs to be extended -- Brent Nelson) • Measure: • the Z’ mass and width and show that it is from U(1)N of the E6SSM with g’¼ g1 • the lightest Higgs boson mass and see if it exceeds the NMSSM limit • the SUSY and exotic fermion spectrum • Deduce: • the exotic couplings and SUSY soft masses at low energy • the SUSY masses at the GUT scale Steve King, LHC Inverse Workshop, MCTP

  19. Running up MString gaugino masses E8£ E8! E6 MGUT E6 MR3 MR2 RH s MR1 Superpartners, Z’, Exotics 5+5-bar’s TeV MW Steve King, LHC Inverse Workshop, MCTP

  20. Final remarks • Running up the soft scalar masses will be tricky due to: • Large exotic fermion masses which must be disentangled • Exotic thresholds in the TeV region • Extra U(1)N leading to additional D-term contribution to soft masses (see next talk by David Morrissey) Such issues are presently under discussion at this workshop (with Gordy Kane, Lisa Everett,..) Steve King, LHC Inverse Workshop, MCTP

More Related