1 / 32

Latest New Phenomena Results from

1. Latest New Phenomena Results from. ITEP, Moscow 26.11.2007. For the DO Collaboration. Alexey Popov (IHEP, Protvino). 2. New Phenomena with. Supersymmetry:. Squarks/Gluinos Charginos/Neutrallinos. Leptoquarks (2 generation) RS Gravitons Extra Gauge Bozons ( )

jonah
Download Presentation

Latest New Phenomena Results from

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. 1 Latest New Phenomena Results from ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  2. 2 New Phenomena with • Supersymmetry: • Squarks/Gluinos • Charginos/Neutrallinos • Leptoquarks (2 generation) • RS Gravitons • Extra Gauge Bozons ( ) • Excited Fermions ( ) • Long-lived Particles Results from statistics ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  3. 3 Data Set “Run IIa” ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  4. 4 Supersymmetry • Most studied extension of the Standard Model to solve many of its shortcomings • New (s)particles, differing from their SM partners by spin 1/2 R-parity: MSSM: R-parity conservation - LSP is stable, s-partners are created in pairs • SUSY must be broken: mSUGRA, GMSB etc. • mSUGRA parameters: ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  5. 5 Supersymmetry: squarks and gluinos • MSSM (mSUGRA) • R-parity conserved (LSP stable) “di-jet” Low , (at least 2 jets) “3-jet” Medium , (at least 3 jets) “gluino” High , (at least 4 jets) ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  6. 6 Squarks and gluinos: results mSUGRA parameters ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  7. 7 Squarks and gluinos: results Using minimal cross-section ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  8. 8 Squarks and gluinos: results CDF ( ): Iso-squark/gluino mass Yellow band: variations due to PDF uncertainties and renormalization/factorization scale variations ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  9. 9 Charginos and Neutrallinos: 3l - state • Gaugino pair production via EW interactions • Small cross-sections (0.1 – 0.5 pb) • R-parity conservation LSP stable • LSP escapes detection large MET • SUSY signature: Small cross-sections but very clean signature • Two electrons or muons • Third lepton • Large MET ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  10. 10 Charginos and Neutrallinos: 3l - state ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  11. Charginos and Neutrallinos: 3l - state 11 ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  12. 12 Charginos and Neutrallinos: Like-sign mm Very soft third lepton possible. Instead of requiring 2l+track require 2l of same charge: low background ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  13. 13 Charginos and Neutrallinos: Like-sign mm ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  14. 14 Trilepton results “Heavy squarks”: maximal production cross-section “3l-max”: mSUGRA with light sleptons, large BR(3l) “large-m0”: W/Z exchange dominates, small BR(3l) in “3l-max” scenario ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  15. 15 Search for GMSB in diphoton final states Gauge Mediated SUSY Breaking • achieved by the introduction of the new chiral • supermultiplets (messengers) which couple to the source • of SUSY breaking • LSP is gravitino, NLSP (neutrallino or slepton) • decays to LSP and photon, LSP escapes detection • Signature: gg + MET One dimensioned parameter L – effective energy scale of SUSY breaking. ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  16. 16 Leptoquarks • Leptoquark – boson with third-integer charge, carrying lepton and quark quantum numbers (GUT, Technicolor, Compositeness) • Three generation, each coupling to one fermion generation only • Pair production: no dependence from LQ coupling to l and q Maximal ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  17. 17 Leptoquarks: Second Generation M(LQ) > 214 GeV (b=0.5) CDF Run II ( ) M(LQ) > 170 GeV (for mn+jets) M(LQ)>208 GeV (mm,mn,nn combined) ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  18. 18 Randall-Sundrum Gravitons RS Model • Use Extra Dimensions (ED) to address a hierarchy problem • One 5th (infinite) ED with warped geometry • Gravity is localized on a Plank brane (other than SM brane) • Gravitons appear as a KK excitations in SM brane Signature: narrow, high-mass resonances decaying to ll or gg Two parameters: – mass of the first excited mode of the G – dimensionless coupling to the SM fields ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  19. 19 Randall-Sundrum Gravitons (combined) CDF ( ): ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  20. 20 New Gauge Bosons Predicted in several beyond SM scenarios (GUT, left-right symmetric models, etc.) (SM-like W) CDF (Run II, en) ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  21. 21 New Gauge Bosons Previous DO Run II results: (SM-like couplings to fermions) CDF Run II ( ) Small excess of data in ee channel at 240 – 250 GeV ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  22. 22 Lepton compositeness • Quarks and leptons may be made of smaller “pieces” (preons) • This allows excited states ( ) • Contact Interaction (CI) and Gauge Interactions • – compositeness scale parameter Expected signal for Data: SM expectations: events events ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  23. 23 Lepton compositeness CDF Run II ( ): DO Run II ( ): CDF Run II ( ): ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  24. 24 Long-lived particles decaying into Z • Predicted in many “beyond the SM” models (GMSB SUSY, hidden valley models, models with extended Higgs sector, fourth generation quarks ( ), e t c.) • Fourth generation quarks model was chosen as a benchmark, events with at least one Z decaying to state were selected ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  25. 25 Long-lived particles decaying into Z Benchmark: No excess of events at a large distance from the beam Calculated limits (mass vs. ct plot) ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  26. 26 Conclusion • Many searches for beyond Standard Model effects are progressing at Tevatron, you can find much more results on the WWW DO NP page: http://www-d0.fnal.gov/Run2Physics/WWW/results/np.htm CDF “Exotic” page: http://www-cdf.fnal.gov/physics/exotic/exotic.html • Standard Model works pretty well and no significant deviations so far have been observed at DO and CDF • All search analysis are benefiting from more data and we expect with in Run II to increase data set by a factor of ~5 – 10 • Discoveries may come later – stay tuned! ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  27. Backup slides

  28. B1 Squarks: t + jets + MET • In some mSUGRA parameters region (lightest SUSY partner of t) might be the lightest of all sleptons • Enhanced BR to t –leptons via • Dominant squark pair production • Signature: at least one t (decaying hadronically) + jets + MET • mSUGRA parameters region: ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  29. B2 Squarks: t + jets + MET ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  30. B3 Squarks: scalar top Signature: 2 c-jets + MET ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  31. B4 Leptoquarks: third generation (tbtb state) M(LQ) > 180 GeV (b=1) CDF ( , ): M(LQ) > 235 GeV (b=1) First generation ( ) M(LQ)>241(256) GeV (b=1) M(LQ)>218(234) GeV (b=0.5) (combined Run I and Run II) ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

  32. B5 Perspective ITEP, Moscow 26.11.2007 For the DO Collaboration Alexey Popov (IHEP, Protvino)

More Related