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SUSY Search at Future Collider and Dark Matter Experiments

SUSY Search at Future Collider and Dark Matter Experiments. D. P. Roy Homi Bhabha Centre for Science Education Tata Institute of Fundamental Research Mumbai – 400088, India & Instituto de Fisica Corpuscular, CSIC-U. de Valencia Valencia, Spain. Outline. SUSY : Merits & Problems

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SUSY Search at Future Collider and Dark Matter Experiments

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  1. SUSY Search at Future Collider and Dark Matter Experiments D. P. Roy Homi Bhabha Centre for Science Education Tata Institute of Fundamental Research Mumbai – 400088, India & Instituto de Fisica Corpuscular, CSIC-U. de Valencia Valencia, Spain

  2. Outline • SUSY : Merits & Problems • Nature of LSP : Bino, Higgsino or Wino • DM Constraints on Bino, Higgsino & Wino LSP Scenarios ( mSUGRA & mAMSB Models) • Bino LSP Signals at LHC • Higgsino & Wino LSP Signals at CLIC • Bino, Higgsino & Wino LSP Signals in DM Expts • Nonminimal Models for Higgsino, Wino & Bino LSP

  3. WHY SUSY : • Natural Soln to the Hierarchy Problem of EWSB • Natural (Radiative) Mechanism for EWSB • Natural Candidate for the cold DM (LSP) • Unification of Gauge Couplings @ GUT Scale γ γ h - e μ e e t Split SUSY solves 2 at the cost of aggravating1. We shall consider a more moderate option, allowing PROBLEMS WITH SUSY : • Little Hierarchy Problem 2. Flavour & CP Viol. Problem de mh > 114 GeV (LEP)  m > 1 TeV

  4. Nature of the Lightest Superparticle (LSP) in the MSSM: Exception : Mii ≈ Mjj  tan 2θij = 2Mij / (Mii – Mjj) large “Well-tempered Neutralino Scenario” Arkani-Hamed, Delgado & Giudice Astrophysical Constraints  Colourless & Chargeless LSP Direct DM Detection Expts  LSP not Sneutrino Diagonal elements : M1, M 2, ±μ in the basis Nondiagonal elements < MZ Exptl Indications  M1, M 2, μ> 2MZ in mSUGRA

  5. DM Relic Density Constraints on Bino, Higgsino & Wino LSP Scenarios mSUGRA: SUSY Br in HS communicated to the OS via grav. Int.  m0 , m ½ ,tanβ, A0 , sign (μ) at GUTscale ( A0 = 0 & +ve μ) RGE ( Weak Sc masses) Imp Weak Sc Scalar mass MHu || (LEP) RGE: Hyperbolic Br (tanβ > 5) of μ2 :

  6. Chattopadhyay et al m0 ~ m1/2  TeV (Bino LSP) mh > 115 GeV  m1/2 > 400 GeV (M1>2MZ)  also large sfermion mass Binodoesnot carry any gauge charge  Pair annihilate via sfermion exch Large sfermion mass  too large Ωh2 Except for the stau co-ann. region

  7. A Z W FP

  8. Wino LSP (mAMSB model) SUSY braking in HS in communicated to the OS via the Super-Weyl Anomaly Cont. (Loop) m3/2 , m0 , tan β, sign (μ) RGE  M1 : M2 : |M3| ≈ 2.8 : 1 : 7.1 including 2-loop conts

  9. Chattopadhyay et al W W W Robust results, independent of other SUSY parameters (Valid in any SUSY model with Wino(Higgsino) LSP)

  10. Bino LSP Signal at LHC : Canonical Multijet + Missing-ET signal with possibly additional jets (leptons) from cascade decay (Valid through out the Bino LSP parameter space, including the Res.Ann Region) Focus Point Region: Inverted Hierarchy

  11. Chattopadhyay et al Focus Pt SUSY Signal at LHC

  12. Co-annihilation region Guchait & Roy μ>0 BR ≈ 1 BR = 1 τ is soft, but Pτ≈+1 μ<0 One can use Pτto detect the Soft τ coming from

  13. 1-prong hadronic τ decay (BR≈0.5) With pT > 20 GeV cut for the τ-jet the τ misid. Probability from QCD jets goes down from 6% for R > 0.3 (pTπ±> 6 GeV) to 0.25% for R > 0.8 (pTπ± > 16 GeV), while retaining most Of the signal.

  14. Chottopadhyay et al Higgsino & Wino LSP Signals at CLIC: ν e+ χ+ e+ W W,B e- γ χ- e- ν γ • π± are too soft to detect at LHC without any effective tag • Must go to an e+e- Collider with reqd. beam energy (CLIC) Chen, Drees, Gunion OPAL (LEP) χ± decay tracks : Δm < 1 GeV  χ± and /or decay π± track with displaced vertex in MVX Δm > 1 GeV  2 prompt π± tracks (Used by OPAL to beat ννγ background)

  15. Higgsino LSP Signal at 3 TeV CLIC : mχ= μ ≈ 1 TeV ν e+ χ+ e+ W W,B e- γ χ- e- ν γ Luminosity = 103 ev/fb # ev 106 103 (χ± decay π± tracks)

  16. Polarized e- (80% R) & e+ (60% L) beams :  Suppression of Bg by 0.08 & Sig by 0.8  Increase of S/B by ~ 10 # ev 104 102

  17.  χπ+ χπ- ν e+ χ+ W W,B e- γ χ- ν γ Prompt π± tracks in the Background from Beamstrahlung e+ γ π+ π- γ e- Beamstrahlung Bg f ≈ 0.1: Size of fB present for Mrec < 2 TeV  Estimate of fB for Mrec > 2 TeV Any Excess over this Estimate  χ signal & χ mass

  18.  χπ+ χπ- ν e+ χ+ e+ W W e- γ χ- e- ν γ • Δm = 165 – 190 MeV for M2 ≈ 2 TeV & μ > M2 • cτ = 3-7 cm (SLD MVX at 2.5 cm  2 cm at future LC) • Tracks of as 2 heavily ionising particles along with their decay π± tracks. Wino LSP Signal at 5 TeV CLIC : mχ= M2 ≈ 2 TeV Both Wino Signal and Neutrino Bg couple only to e-L & e+R. One can not suppress Bg with polarized beams.  But one can use polarized beams to increase both Signal and Bg rates. Polarized e-L (80%) & e+R (60%)  Probability of e-Le+R = 72% (25% Unpolarized)  Increase of Signal and Bg rates by factors of 72/25 ≈ 3. Bg effectively suppressed due to a robust prediction of charged and neutral wino mas diff. Δm γ, Z Discovery potential is primarily determined by the number of Signal events.

  19. # ev Sig ~ 100 (300) events with Unpolarized (polarized) beams 103 102 The recoiling mass Mrec > 2mχ helps to distinguish Sig from Bg & to estimate mχ.

  20. Bino, Higgsino & Wino LSP Signals in Dark Matter Detection Expts 1. Direct Detection (CDMS, ZEPLIN…) χ χ Ge H Spin ind. Best suited for Focus pt. region  Less for co-ann & res.ann regions χ χ Ge Unsuited for (Suppressed both by Hχχ coupling and large χ mass) p Z Spin dep. p 2. Indirect Detection via HE ν from χχ annihilation in the Sun (Ice Cube,Antares)

  21. 3. Detection of HE γ Rays from Galactic Centre in ACT (HESS,CANGAROO,MAGIC,VERITAS) W χ χ χ+ χ+ χ χ W vσWW ~ 10-26 cm3/s Cont. γ Ray Signal (But too large π0γ from Cosmic Rays) Wπ0sγs γ W • vσγγ~ vσγZ ~ 10-27-10-28 cm3/s • Discrete γ Ray Line Signal (Eγ≈mχ) (Small but Clean) W W γ(Z)

  22. γ flux coming from an angle ψ wrt Galactic Centre mSUGRA ∫ΔΩ=0.001srγdΩ (NFW) Discovery limit of ACT Chattopadhyay et al ∫ΔΩ=0.001srJ(0)dΩ≈ 1 sr (Cuspy:NFW), 103 (Spiked), 10-3 (Core)

  23. mAMSB Discovery limit of ACT Chattopadhyay et al HESS has reported TeV range γ rays from GC. But with power law energy spec  SNR  Formidable Bg to DM Signal. The source could be GC (Sgr A*) or the nearby SNR (Sgr A east) within its ang. res. Better energy & angular resolution to extract DM Signal from this Bg.

  24. Higgsino, Wino & Bino LSP in nonminimal SUSY models LSP in SUGRA models with nonuniversal 1)scalar & 2)gaugino masses 1) J.Ellis et al,…. 2) Chattopadhyay & Roy,….

  25. Wino LSP in 1)Nonminimal AMSB & 2)String models In these models: 1) Tree level SUSY breaking contributions to gaugino and scalar masses † m (tree) ~ 100 Mλ(AMSB) Giudice et al, Wells 2) String Th: Tree level SUSY breaking masses come only from Dilaton field, while they receive only one-loop contributions from Modulii fields. Assuming SUSY breaking by a Modulus field  Mλ& m2 at one-loop level  M2 < M1 < M3 similar to the AMSB ( Wino LSP) & m ~ 10 Mλ Brignole, Ibanez & Munoz ‘94

  26. M3 = 300, 400, 500 & 600 GeV Bino LSP in Non-universal Gaugino Mass Model King, Roberts & Roy 07 Bulk annihilation region of Bino DM (yellow) allowed in Non-universal gaugino mass models

  27. Light right sleptons Even left sleptons lighter than Wino =>Large leptonic BR of SUSY Cascade deacy via Wino

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