1 / 27

X. Higgs Bosonen in Supersymmetrie

X. Higgs Bosonen in Supersymmetrie. Standard Modell: 1 komplexes Higgs Duplett (4 Komponenten) 1 Vakuumerwartungswert u/Ö2 = 174 GeV 3 massive Eichbosonen (W + , W - , Z 0 ) Eine mögliche Anregung übrig: 1 neutrales Higgs Boson h Supersymmetrie

haracha
Download Presentation

X. Higgs Bosonen in Supersymmetrie

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. X. Higgs Bosonen in Supersymmetrie • Standard Modell: • 1 komplexes Higgs Duplett (4 Komponenten) • 1 Vakuumerwartungswert u/Ö2 = 174 GeV • 3 massive Eichbosonen (W+, W-, Z0) • Eine mögliche Anregung übrig: • 1 neutrales Higgs Boson h • Supersymmetrie • 2 komplexe Higgs Dupletts (8 Komponenten) • 3 massive Eichbosonen (W+, W-, Z0) • 5 mögliche Anregungen übrig: • 3 neutrale Higgs Bosonen: h, H, A • 2 geladene Higgs Bosonen: H+, H- • In niedr. Ordnung 2 Parameter :tan = u2/u1undmA

  2. X.1. Higgs Phänomenologie in Supersymmetrie • In mehr Detail (Martin, 7.1.) • 2 komplexe Isospindupletts  8 reelle skalare Felder • 3 Goldstone Felder (G+, G0, G-) verschwinden in massiven W+, Z0, W- • Verbleiben 3 neutrale (h0, H0, A0) und 2 geladene (H+, H-) Higgs Bosonen

  3. MSSM on tree level • Minimal Supersymmetry: • 3 neutral Higgs Bosons: h, H, A • 2 charged Higgs Bosons: H+, H- • at tree level, 2 parameters : tan = v2/v1 and mA • Stephen Martin, hep-ph/97-09356 • gMSSM =xgSM

  4. MSSM at 2-loop level S.Heinemeyer in J.Ellis et al CERN-PH-TH/2007-012 • Loop level (constrained MSSM): • SUSY breaking parameters, assumed to be unified at some scale : • gluino mass and Higgs mass parameter  Mğand • SU(2) gaugino mass term unified at MGUT  M2 at MEW • sfermion mass terms : common at MEW  Msusyat MEW • sfermion trilinear couplings : common at MEW  A at MEW mixing parameter in the stop sector :  Xt= At -  cot • Total:8parameters • mt=171.4 GeVmeasured • M2, Msusy, Mğ,  and Xtchosen to define a “benchmark scenario” • tan and mA free to vary (tan[1, 50] and mA[50, 1000]GeV) • Higgs Masses • A ~ degenerate in mass with • h at low masses • H and H± high masses • h mass < 130 GeV (all scenarios)

  5. Benchmark scenarios • Examples: Description: http://arxiv.org/abs/hep-ph/0202167M. Carena, S. Heinemeyer, C.E.M. Wagner, G. Weiglein

  6. Easy patternfor large mA • Features of • LargemA and mH: • a = b ± 90° • h is SM-like w/ maximal mass • gMSSM =xgSM • H/A/H±produced via Fermion-couplings! • Large enhancement of SUSY-Higgs ~(tan)2possible • Large tan:b- associated production • Small tan:t- associated production

  7. Example: WidthsandBranchingRatiostott • From Ph.D. thesis, Jana Schaarschmidt, TU Dresden, 2010 • Widths • H,A:enhanced by tan b • h:above m ~ 200 GeVSM-like (narrow) • Branching ratios • SM:tt negligible above 160 GeV • SUSY:tt always sizableincreasing w/ tan bA and H

  8. Cross Sections

  9. Can we see the additional Higgses? • good news: • at least one Higgs boson observable for all parameters in all four MSSM benchmark scenarios • bad news: • significant area where only lightest Higgs boson h is observable • e.g. Higgs discovery, ATLAS prel., 300 fb-1 (M. Schumacher, hep-ph/0410112, ATL-com-phys-2004-070)

  10. X. 2. Search for Neutral Higgs Bosons • How to discover?

  11. Associate A/H production with b-quarks • Basic 2  2 diagram • Corresponding to b-pdf in Proton • Details much more complex • Add 23, 22, and 21 w/o double counting • Solution: SHERPA MC generator w/ CKKW matchingbetween Matrix Element and Parton Shower contributions • Jet fractions agree with analytic calculation (Harlander+Kilgore) • Example: full (down-type) leptonic modes • b h/H/A  b µ+µ- • b h/H/A  b t+t- b ℓ+νν ℓ-νν • Main backgrounds (several 100 pb) • tt (b)b µ+ν µ-ν tt  (b)b ℓ+ν ℓ-ν • qZ ‘‘b‘‘µ+µ- qZ ‘‘b‘‘t+t-

  12. MassResolutions tan b = 15, mA=132 GeV tan b = 15, mA=150 GeV M.Warsinsky, DoktorarbeitDresden, 200814 TeV, 30 fb-1~ 2014 / 2015 J.Schaarschmidt, DiplomarbeitDresden, 2007 14 TeV, 30 fb-1~ 2014 / 2015 • µ+µ-: exzellente Massenauflösung ~ 3 GeV • h/A/H trotzdem nicht getrennt, aber Breite messbar • t+t-: gröbere Massenauflösung 30 - 40 GeV • benutzt kolineare Näherung des Tau Zerfalls

  13. Collinear Approximation

  14. Performance (Ph.D. Thesis, Jana Schaarschmidt, 2010)

  15. tt Leptonnn + Hadronsn (ATLAS) • Typical signal and background distributions at 14 TeV without b-Jet with b-Jet

  16. Extraction of Z ttbackground mttshapefromdata • Use Zmm and Zee and reweight the lepton signals • ttmnn mnn : Just needs reweighting of track momenta • ttenn enn : Needs also reweighting of *longitudinal* shower shape • Very successful results Zmm (Jana Schaarschmidt, 2007) Zee (Kathrin Leonhardt, 2008, Patrick Czodrowski, 2009)

  17. Expectedsensitivities • Estimated reach after 1 fb-1 at 7 TeV (maybe end of 2011?) • Discovery reach after 30 fb-1 at 14 TeV (2014/2015?)

  18. X.3. Charged H± • Mass and Couplings: • mH±2 = mA2 + mW2 in MSSMw/ negligible radiative corrections • No coupling to W, Z • Two fermionic couplings dominant: • Minimum tb coupling at tan b = √(mt / mb ) ≈ 7

  19. LEP Limits • Direct LEP limits for e+e-  H+H-stop at ~mW due to W+W- backgr. • MSSM: BR(H±tn) dominant for mH± < mt  mH± >~ 85 – 89 GeV • LEP direct H± limits: • Relevant in non-SUSY 2-Higgs Doublet Models (2HDM) • Marginal in MSSM, since mH±2 = mA2 + mW2 anyway

  20. Search for Charged Higgs Bosons • New input from b-physics!

  21. Newly developping constraints from b-decays • Gino Isidori, 3rd Workshop: Flavour in the Era of the LHC, 2006 • Well defined pattern for exp. observables • Starting to give useful constraints • Most limits in literature for 2HDM !No systematic studies for MSSM yet (too many param.!)

  22. B tn: New Physics t± t± ~ ~ rBtn e0tanb » 1 • Leading-order H± contribution! • 2HDM (W.S.Hou, PRD 48 (1993) 2342) • rBtn= BR(2HDM)/BR(SM) = • MSSM (G.Isidori, P.Paradisi, hep-ph/0605012) • Gluino-induced corrections (e0(mg,mq) ~ 10-2)to down-type Yukawa couplings considerable for large tanb • rBtn= BR(MSSM)/BR(SM) = • Amplitude M(H±) has opposite sign! • suppression • |M (H±)| < |M (W±)| • (near-)cancellation • |M (H±)| ~ |M (W±)| • (near-)compensation • |M (H±)| ~ 2|M (W±)| • enhancement • |M (H±)| > 2|M (W±)|

  23. B tn: Experimental Signature

  24. B tn: First Observations C.Bozzi, HCP2007 2.6s

  25. MSSM interpretation of B- andotherconstraints • G. Isidori, F. Mescia, P. Paradisi, D. Temes: hep-ph/0703035 • 1.01 < Rbsg < 1.24 (1 sigma): blue lines • 0.8 < R‘Btn < 0.9 (future guess!): black lines • current 1-sigma would be 0.7 < R‘Btn < 1.3 • NB: 2nd solution for mH < 200GeV not shown! • B → μ+μ− < 8.0 × 10−8: allowed below green line • DmBs = 17.35 ± 0.25 ps−1 : allowed below gray line • (g-2)μ: 2 < aμ(exp− SM)/10−9 < 4 : purple lines • Dark Matter (~Bino) density: light blue forbidden M˜q= 1.5 TeV AU= −1 TeVμ = 0.5 TeVM˜ℓ = 0.3 TeV M˜q= 1.5 TeV AU= −1 TeVμ = 1.0TeVM˜ℓ = 0.4 TeV

  26. H± at LHC H±(fb) 95 130 170 215 310 mH±(GeV) t± M. Schumacher, ATL-com-phys-2004-070 H± t H± • Two main production processes • for mH±< mt • gg  t t  bW bH± • for mH±> mt • bg  tH± bW H± • Two main decay modes • H± tn, dominant for “small“ mH± • below 200 GeV (large tan b > 10) • below 150 GeV (small tan b) • H± tb,approaches for “large“ tan b • BR(tb)/BR(tn) = (mb/mt)2 ~ 6

  27. H± Discovery reach(ATLAS, TDR 2008) • z.B. für mH±> mt : tH± bW tn • Transversale Massenverteilung nach 30 fb-1 • Entdeckungs und Ausschlusspotenzial (Alle Kanäle kombiniert) ~

More Related