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Phenomenology of Twin Higgs Model

Phenomenology of Twin Higgs Model

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Phenomenology of Twin Higgs Model

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  1. Phenomenology of Twin Higgs Model Shufang Su • U. of Arizona Hock-Seng Goh, Shufang Su Work in progress

  2. Outline - • Twin Higgs Model • Twin Higgs mechanism • Left-right Twin Higgs model • New particles and model parameters • Collider phenomenology • Heavy top quark • Heavy gauge bosons • Higgses

  3. Twin Higgs mechanism - Higgs as pseudo-Goldstone boson of a global symmetry Its mass is protected against radiative corrections • Little Higgs mechanism: collective symmetry breaking • Twin Higgs mechanism: discrete symmetry Mirror symmetry Type IA TH: Chacko, Goh, Harnik, hep-ph/0506256 Type IB TH: Chacko, Nomura, Papucci, Perez, hep-ph/0510273 Left-right symmetry Type II TH: Chacko, Goh, Harnik, hep-ph/0512088

  4. Left-right Twin Higgs model • SM Higgs doublet • EWSB SM neutral Higgs: H 3 eaten by heavy gauge bosons - • Global U(4) , with subgroup SU(2)L SU(2)R  U(1)B-L gauged • Left-right symmetry: gL=gR (yL=yR) A linear realization U(4) U(3) SU(2)L SU(2)R U(1)B-L  SU(2)LU(1)Y 7 GB

  5. Twin Higgs mechanism - Quadratic divergence forbidden by left-right symmetry gL=gR=g U(4) invariant, does not contribute to the mass of GB Non-linear realization Log contribution: mH g2f / (4 ), natural for f  TeV

  6. Left-right Twin Higgs model - Fermion sector: Top quark mass: Top quark mass eigenstates: SM top and tH EW precision constraints on SU(2)R gauge boson mass  f  2 TeV Introduce another Higgs field that only couples to gauge sector Which has a larger VEV

  7. Left-right Twin Higgs model • SM Higgs doublet • EWSB SM neutral Higgs: H SU(2)L Higgs doublet H1, H20 • U(4)  U(4), with gauged SU(2)LSU(2)RU(1)B-L + LR symmetry - Couple to gauge boson only 3 eaten by heavy gauge bosons Left 3 Higgses: neutral Higgs 0, charged Higgs  U(4)  U(3) SU(2)L  SU(2)R  U(1)B-L  SU(2)LU(1)Y  U(4)  U(3) 7 GB 7 GB f2 f1

  8. New particles - • Heavy gauge bosons:WH, ZH m2WH,ZH g2(f12+f22) • Heavy top:tH m2TH M2+y2f12 • Other SU(2)R Higgses: m2  g4/(162)f22 log(/gf2) 0 m20  B (f2/f1) B: small, (50-100 GeV)2 • Other SU(2)L Higgs H1m2H1, H20  H20 : soft symmetry breaking, O(f1)

  9. Model parameters fixed by Higgs VEV - • Model parameters: f1, (f2, y), , M, B,  • Determine particle masses and interactions = 4f1 or 2f1 M=150 GeV B=50 GeV  = f1/2 fixed by top quark mass

  10. Heavy top tHproduction - • single heavy top production • heavy top pair production

  11. Heavy top tHdecay 3 b + 1 j + 1 lepton + missing ET j b W b  l t tH l b j 1 b + 1 j + 1 lepton + missing ET  W  tH b -

  12. Heavy gauge bosonproduction - • Drell-Yan process

  13. ZHdecay b 2 b + 2 j + 1 lepton + missing ET q t W q ZH b l t W  - • ZH

  14. WHdecay tHb: 4b + 1 lepton + missing ET tHbW : 2b + 1 lepton + missing ET tHtZ: 2b + 3 lepton + missing ET - • WH

  15. Higgses - SM Higgs • mH 150-170 GeV, depending on f1,  and M • Higgs searches: • gg  H  ZZ*  llll • gg  H  WW*  ll • WBF  qqH  qqWW*  qqll SU(2)R Higgs: 0,  0  bb j   tb 2b + 1 lepton + missing ET

  16. 0 4 b + 1 lepton + missing ET b b t l  W WH b 0  b - Neutral Higgs 0 • gg  0  bb, QCD background overwhelming • no W0, Z0 associated production (no such coupling) • bb0 , tb0,tt0cross section small • Produced via the decay of heavy particles

  17.  j b W b  l t tH 3 b + 1 j + 1 lepton + missing ET b  - Neutral Higgs  • no W, Z associated production (no such coupling) • bb , tb,ttcross section small • Produced via the decay of heavy particles

  18. H1, H20 - Higgs that couple to gauge boson only:H1, H20 • H1H20,H1H1, H20H20, associated production (small) • H20stable: missing energy • H1 H20 + soft jets/leptons if decay fast enough: appears as missing energy if decay slow: track ! H20: good dark matter candidates

  19. M=0 case   t + b (100%) - Top Yukawa: f1 v tH = (TL, tR), mtH = yf1 tSM = (tL, TR), mt = yv Gauge coupling Yukawa coupling • 0 tH tH • 0 tt • 0 tH t • H t  t • H tH tH (small) • H tH t • W  t  b • W  tH b • WH t  b • WH tH b • Z  t  t • Z  tH tH • Z  tH t • ZH t  t • ZH tH tH • ZH tH t •  tH b •  tb X

  20.  decay 0  bb: bbqq final states huge QCD bg H ZZ*, WW* small signal - • No two body decay • Leading decay: 3 body off-shell

  21.  discovery Difficult unless   Hqq - small signal

  22. 0 discovery difficult absent - small signal

  23. Heavy top tHdiscovery 100% either huge QCD bg Or small signal absent - • single, pair production does not change much. • decay: only tH b  (100%)

  24. Heavy gauge bosondiscovery either huge QCD bg Or small signal absent - • ZH, WH drell-yan cross section does not change • ZH: ZH ll does not change much  Br(ZH t tH) =0 • WH: difficult For M=0 discovery of almost all the particle are difficult except for ZH

  25. Conclusions - • Left-right twin Higgs model: Higgs as pseudo-goldstone boson quadratic divergence forbidden by left-right symmetry • New particles • Heavy gauge boson: WH, ZH • Heavy top quark tH • New Higgses: 0, , H1, H20 (DM) • M0: rich collider phenomenology • M=0: difficult except for ZH • Future work • Pick certain channel for detailed study: background, cuts,… • Identify twin Higgs mechanism • Dark matter study • Comparison with other models, e.g., little higgs