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Measurement of Dark Matter Relic Density in the mSUGRA Co-annihilation Region at the LHC

Measurement of Dark Matter Relic Density in the mSUGRA Co-annihilation Region at the LHC. Teruki Kamon In collaboration with Richard Arnowitt , Bhaskar Dutta , Alfredo Gurrola , Abram Krislock , and David Toback Texas A&M University

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Measurement of Dark Matter Relic Density in the mSUGRA Co-annihilation Region at the LHC

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  1. Measurement of Dark Matter Relic Density in the mSUGRA Co-annihilation Region at the LHC TerukiKamon In collaboration with Richard Arnowitt, BhaskarDutta, Alfredo Gurrola,Abram Krislock, and David Toback Texas A&M University The 16th International Conference on Supersymmetry and the Unification of Fundamental Interactions (SUSY2008), Seoul, Korea, June 16 - 21, 2008 Measurement of Dark Matter Relic Density at the LHC

  2. Probing the SUSY Dark Matter Dark Matter (DM) Particle in SUSY & Cosmological Connection WSUSY DM≟WCDM SUSY Signal in Co-annihilation (CA) Region DM Density (Wh2 ) at the LHC Arnowitt, Dutta, Gurrola, Kamon, Krislock, Toback PRL100 (2008) 231802 or arXiv:0802.2968 (hep-ph) For earlier studies, see Arnowittet al., PLB 649 (2007) 73; Arnowittet al,, PLB 639 (2006) 46 Measurement of Dark Matter Relic Density at the LHC

  3. DM Particle in SUSY CDM =Neutralino ( ) SUSY Astrophysics WMAP 5: 23.3% ( 1.3%) Measurement of Dark Matter Relic Density at the LHC

  4. Choosing Benchmark Model … An accidental near degeneracy occurs naturally for light stau in many models. The mSUGRA model is one of them and chosen as our benchmark scenario. 4 parameters + 1 sign Key experimental constraints Measurement of Dark Matter Relic Density at the LHC

  5. DM Allowed Regions R. Arnowitt et al., Phys. Lett. B538 (2002) 121 4 Smoking Gun of CA Region? R. Arnowitt et al., Phys. Lett. B639 (2006) 46 mSUGRA tanb= 40 A0 = 0, m > 0 3 DM = 5-15 GeV DM (GeV) 4 1 2 • Excluded by • Rare B decay bsg • No CDM candidate • Magnetic moment of muon 1 2 3 Measurement of Dark Matter Relic Density at the LHC

  6. Proving WSUSY DM in Inclusive Jets+ETmiss LM1( Low Mass Case 1) ? WSUSY DM≟WCDM Nojiri, Polesselo, Tovey, JHEP 0603 (2006) 063 Arnowittet al., to appear in PRL (2008) • Dilepton mass “edge” in the c20ee/mmc10 decays for reconstruction of SUSY Masses  W Measurement of Dark Matter Relic Density at the LHC

  7. Dilepton Endpoint in CA Region In the CA region, the ee and mmchannels are almost absent. pTt > 20 GeV is essential! ETvis(true) > 20, 20 GeV • Program: • Establish the “CA region” signal • Determine SUSY masses/mSUGRA parameters • MeasureWch2and compare with WCDMh2 Number of Counts / 1 GeV ETvis(true) > 40, 20 GeV ETvis(true) > 40, 40 GeV Measurement of Dark Matter Relic Density at the LHC

  8. SUSY Anatomy in the CA Region Mjtt &Mjt ETjet> 100 GeV SUSY Masses pTt> 40 GeV 97% Mtt 100% [Key Assumption] et = 50% , fake rate 1% for pTvis > 20 GeV (CDM) pTt> 20 GeV pT(t) Measurement of Dark Matter Relic Density at the LHC

  9. OS-LS Mtt Distribution Uncertainty Bands with 10 fb-1 Clean peak even for low DM Independent of the gluino masses! Measurement of Dark Matter Relic Density at the LHC

  10. OS-LS Slope(pTsoft ) Independent of the gluino masses! Uncertainty Bands with 10 fb-1 Measurement of Dark Matter Relic Density at the LHC

  11. Mjtt Distribution 1) Mtt < Mttendpoint; Jets with ET > 100 GeV; Mjtt masses for each jet 2) Choose the 2nd large value  Peak value ~ True Value Mjtt(2)(GeV) Measurement of Dark Matter Relic Density at the LHC

  12. Meff Distribution • Excess in ETmiss + Jets •  SUSY scale measurement at 10-20%. e.g., Hinchliffe and Paige, Phys. Rev. D 55 (1997) 5520 MeffETj1+ETj2+ETj3+ETj4+ ETmiss [No b jets; eb ~ 50%] Meff • ETj1>100, ETj2,3,4> 50; No e’s, m’s with pT > 20 GeV • Meff > 400 GeV; ETmiss > max [100, 0.2 Meff] m1/2 = 335 GeV Meffpeak = 1220 GeV m1/2 = 351 GeV Meffpeak = 1274 GeV m1/2 = 365 GeV Meffpeak = 1331 GeV Measurement of Dark Matter Relic Density at the LHC

  13. Determining SUSY Masses (10 fb-1) 6 equations for 5 SUSY masses 14119 GeV 10 fb-1 Invert the equations to determine the masses We test a gauginounivesality at 15% level. Measurement of Dark Matter Relic Density at the LHC

  14. DM Relic Density in mSUGRA [1] Established the CA region by detecting low energy t’s (pTvis > 20 GeV) [2] Determined SUSY masses using: Mtt, Slope, Mjtt, Mjt, Meff e.g., Gaugino universality test at ~15% (10 fb-1) [3] Measure the dark matter relic density by determining m0, m1/2, tanb, and A0 Measurement of Dark Matter Relic Density at the LHC

  15. Introducing Meff(b) Meff(b)ETj1=b+ETj2+ETj3+ETj4+ ETmiss[j1 = b jet] ETj1>100 GeV, ETj2,3,4> 50 GeV [No e’s, m’s with pT > 20 GeV] Meff(b)> 400 GeV ; ETmiss> max [100, 0.2 Meff] m1/2 = 335 GeV Meff(b)peak = 933 GeV m1/2 = 351 GeV Meff(b)peak = 1026 GeV m1/2 = 365 GeV Meff(b)peak = 1122 GeV Meff(b)peak (GeV) Meff(b)can be used to probe A0 and tanb even without measuring stop and sbottom masses Measurement of Dark Matter Relic Density at the LHC

  16. Determining mSUGRA Parameters • Solved by inverting the following functions: 10 fb-1 Measurement of Dark Matter Relic Density at the LHC

  17. Summary [1] Established the CA region by detecting low energy t’s (pTvis > 20 GeV) [2] Determined SUSY masses using: Mtt, Slope, Mjtt, Mjt, Meff e.g., Gaugino universality test at ~15% (10 fb-1) [3] Measured the dark matter relic density by determining m0, m1/2, tanb, and A0 using Mjtt, Meff,Mtt, and Meff(b) [4] Working on non-minimal case... Teruki Kamon Measurement of Dark Matter Relic Density at the LHC

  18. Backups

  19. Meff m1/2 = 335 GeV Meffpeak = 1220 GeV Meffpeak /M(u_R)=1.75 m1/2 = 351 GeV Meffpeak = 1274 GeV m1/2 = 365 GeV Meffpeak = 1331 GeV Meffpeak (GeV) m1/2 = 335 GeV Meff(b)peak = 933 GeV m1/2 = 351 GeV Meff(b)peak = 1026 GeV Meff(b)peak /M(t_1)=1.84 Meff(b)peak /M(3rd)=1.7 m1/2 = 365 GeV Meff(b)peak = 1122 GeV Meff(b)peak (GeV)

  20. DM Allowed Regions (Illustration) Higgs Mass (Mh) Excluded (Higgs mass) Branching Ratio bsg Excluded (Magnetic Moment of Muon) Mass of Squarks and Sleptons Magnetic Moment of Muon Excluded (Rare B Decay bsg) No CDM Candidate CDM allowed region Mass of Gauginos Co-annihilation Region

  21. Dilepton Endpoint • DM content  Measurements of the SUSY masses • [e.g., M.M. Nojiri, G. Polesselo, D.R. Tovey, JHEP 0603 (2006) 063] • Key: Dilepton “edge” in the c20 decay in dilepton(ee, mm, tt) channels for reconstruction of decay chain. LM1( Low Mass Case 1): [post-WMAP benchmark point B’] s = 55 pb m1/2= 180, m0= 850 Measuring Dark Matter Relic Density at the LHC

  22. Mttpeak vs. X Uncertainty Bands with 10 fb-1 Measuring Dark Matter Relic Density at the LHC

  23. Mjtt Distribution Mtt < Mttendpoint Jets with ET > 100 GeV Mjtt masses for each jet Choose the 2nd large value  Mjtt(2) “other” jet q Peak value ~ True Value Mjtt(2)(GeV) We choose the peak position as an observable. Measuring Dark Matter Relic Density at the LHC

  24. Excess in ETmiss + Jets • Excess in ETmiss + Jets •  SUSY scale measurement at 10-20%. Hinchliffe and Paige, Phys. Rev. D 55 (1997) 5520 Meff MeffETj1+ETj2+ETj3+ETj4+ ETmiss [No b jets; eb ~ 50%] • ETj1>100 GeV, ETj2,3,4> 50 GeV • [No e’s, m’s with pT > 20 GeV] • Meff > 400 GeV; • ETmiss > max [100, 0.2 Meff] CMS HM1 Scenario m1/2= 250, m0= 60 s = 45 fb Measuring Dark Matter Relic Density at the LHC

  25. Mass Measurements mSUGRA Meff(b)peak & Mttpeak …. Sensitive to A0 and tanb Mjttpeak & Meffpeak …. Insensitive to A0 and tanb Measuring Dark Matter Relic Density at the LHC

  26. SUSY Anatomy in the CA Region SUSY Masses 97% 100% (CDM) ETjet> 100 GeV Mjtt &Mjt pTt> 40 GeV Mtt pTt> 20 GeV pT(t) Measuring Dark Matter Relic Density at the LHC

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