1. June 8, 2007LPC Early CMS Physics1 Relic Density in MET+Jets+Taus Sample at the LHC Teruki Kamon Texas A&M University [1] Physics Case in MET+Jets+Taus Sample [2] Specific Tasks on MET+Jets+Taus Events

2. June 8, 2007LPC Early CMS Physics2 [1] Physics Case in MET+Jets+Taus Sample 1) Phys. Lett. B 639 (2006) 46 R. Arnowitt, D. Butta, T. Kamon, N. Kolev, D. Toback 2) Phys. Lett. B 649 (2007) 73 R. Arnowitt, A. Aurisano, D. Butta, T. Kamon, N. Kolev, P. Simeon, D. Toback, P. Wagner 3) To appear R. Arnowitt, D. Butta, A. Gurrola, T. Kamon, A. Krislock, D. Toback [2] Specific Tasks on MET+Jets+Taus Events Jonathan Asaadi, Adam Aurisano, Alfredo Gurrola, Teruki Kamon, Chi-Nhan Nguyen, Alexei Safonov, David Toback, Michael Weinberger

3. June 8, 2007LPC Early CMS Physics3 4321 splitting normal matter and dark matter apart – Another Clear Evidence of Dark Matter – (8/21/06) Dark Matter (Gravitational Lensing) Ordinary Matter (NASA’s Chandra X Observatory) Cosmic Collision of 2 Galaxy Clusters time Approximately the same size as the Milky Way

4. June 8, 2007LPC Early CMS Physics4 Particle Physics and CosmologySUSY CDM = Neutralino ( ) Astrophysics SUSY is an interesting class of models to provide a massive neutral particle (m ~ 100 GeV) and weakly interacting (WIMP). Griest, Seckel ’91

5. June 8, 2007LPC Early CMS Physics5 Minimal Supergravity (mSUGRA) 4 parameters + 1 sign m 1/2 Common gaugino mass at M G m 0 Common scalar mass at M G A 0 Trilinear couping at M G tan  / at the electroweak scale sign(  ) Sign of Higgs mixing parameter (W (2) =  H u H d ) 4 parameters + 1 sign m 1/2 Common gaugino mass at M G m 0 Common scalar mass at M G A 0 Trilinear couping at M G tan  / at the electroweak scale sign(  ) Sign of Higgs mixing parameter (W (2) =  H u H d ) Experimental Constraints

6. June 8, 2007LPC Early CMS Physics6 Experimental Constraints Where are WMAP Favored regions? Magnetic Moment of Muon Higgs Mass (M h ) Branching Ratio b  s  Mass of Squarks and Sleptons Mass of Gauginos No Neutralino LSP Excluded

7. June 8, 2007LPC Early CMS Physics7 Dark Matter Allowed Region Magnetic Moment of Muon Higgs Mass (M h ) Branching Ratio b  s  Mass of Squarks and Sleptons Mass of Gauginos No Neutralino LSP Excluded WMAP Favored region

8. June 8, 2007LPC Early CMS Physics8 [Neutralino-stau coannihilation region] [Focus point region] The lightest neutralino has a larger higgsino component [A-annihilation funnel region] This appears for large values of m 1/2 Note: this narrow band does not disappear even with accurate measurement of CDM. Dark Matter Allowed Regions mSUGRA

9. June 8, 2007LPC Early CMS Physics9 tan  = 40,  > 0, A 0 = 0 Can we measure  M at colliders? Phys. Lett. B 649 (2007) 73 Coannihilation Region

10. June 8, 2007LPC Early CMS Physics10 >4 jet + E T miss + >2  SUSY in Early Stage at the LHC One of the key reactions Unique kinematics

11. June 8, 2007LPC Early CMS Physics11 Kinematical Cuts and Event Selection  E T j1 > 100 GeV, E T j2,3,4 > 50 GeV  M eff > 400 GeV (M eff  E T j1 +E T j2 +E T j3 +E T j4 + E T miss )  E T miss > max [100, 0.2 M eff ] Phys. Rev. D 55 (1997) 5520 Example Analysis

12. June 8, 2007LPC Early CMS Physics12  SUSY mass scale could be measured with an accuracy of 10-20% This measurement does not tell us whether the model can generate the right amount of dark matter The dark matter content is measured to be 23% with an accuracy of around 5% at WMAP  Question: To what accuracy can we calculate the relic density based on the measurements at the LHC? M eff and Relic Density

13. June 8, 2007LPC Early CMS Physics13 >4 jet + E T miss + >2  Anatomy: P T soft E T  > 20 GeV is essential! low energy high energy Slope of P T distribution contains ΔM information More events for larger  M Detecting low energy  ’s are an enormous challenge for the detectors.

14. June 8, 2007LPC Early CMS Physics14 OS Low OS P T histogram with P T of softer  ; High OS P T histogram with P T of harder  E T miss + 2j + 2  Analysis Path Cuts to reduce the SM backgrounds (W+jets, …) E T miss > 180 GeV, E T j1 > 100 GeV, E T j2 > 100 GeV, E T miss + E T j1 + E T j2 > 600 GeV P T  > 20 GeV, P T   > 40 GeV (   = 50%, fake rate 1%) Low OS-LS High OS-LS Low LS High LS Low OS High OS LS Low OS P T histogram with P T of softer  ; High OS P T histogram with P T of harder  Look at  pairs and CATEGORIZE them as opposite (OS) or like sign (LS)

15. June 8, 2007LPC Early CMS Physics15 OS OS-LS LS [1] E T miss, at least 2 jets, at least 2  ’s with P T vis > 20, 40 GeV [2]   = 50%, fake rate 1% [3] Cuts: E T jet1 > 100 GeV, E T jet2 > 100 GeV, E T miss > 180 GeV E T jet1 + E T jet2 + E T miss > 600 GeV P T soft in OS  LS

16. June 8, 2007LPC Early CMS Physics16 We still see the dependence of the P T slope on  M using OS  LS method, P T soft (OS  LS) :  M Dependence

17. June 8, 2007LPC Early CMS Physics17 Anatomy: Di-tau Mass Distribution 10 fb  1 LS OS OS  LS M peak = 47.1 GeV M max (true) = 78.7 GeV OS  LS counts with M  < 100 GeV: Top: 6 counts W+jets: 1 count SUSY : 125 counts Phys. Lett. B 639 (2006) 46

18. June 8, 2007LPC Early CMS Physics18 Anatomy: M(j, ,  ) a) if E T j1  E T j2 > 100 GeV j = j 2 b) if E T j1  E T j2 < 100 GeV j = j n with smaller  R( , j n ) OS LS OS  LS Probing M Squark – M LSP

19. June 8, 2007LPC Early CMS Physics19 How to Establish the Discovery Phys. Lett. B 639 (2006) 46 Phys. Lett. B 649 (2007) 73 Work in progress [1] N OS  LS (Number of OS  LS counts)  5  significance where Significance = N OS  LS /  N OS+LS [2] Clear peak (M peak ) and end-point (M max ) in di-tau mass distribution for OS  LS pairs  Are they consistent with the decay kinematics? [3] M peak (and M max ) on  M and M  2 0. [4] P T slope is used to determine  M. [5] M(j, ,  )Observables

20. June 8, 2007LPC Early CMS Physics20 Example Translation We establish the dark allowed regions from the detailed features of the signals, and accurately measure the masses. We calculate the relic density and compare with WMAP. Work in progress

21. June 8, 2007LPC Early CMS Physics21 [1] Physics Case in MET+Jets+Taus Sample 1) Phys. Lett. B 639 (2006) 46 R. Arnowitt, D. Butta, T. Kamon, N. Kolev, D. Toback 2) Phys. Lett. B 649 (2007) 73 R. Arnowitt, A. Aurisano, D. Butta, T. Kamon, N. Kolev, P. Simeon, D. Toback, P. Wagner 3) To appear R. Arnowitt, D. Butta, A. Gurrola, T. Kamon, A. Krislock, D. Toback [2] Specific Tasks on MET+Jets+Taus Events Jonathan Asaadi, Adam Aurisano, Alfredo Gurrola, Teruki Kamon, Chi-Nhan Nguyen, Alexei Safonov, David Toback, Michael Weinberger

22. June 8, 2007LPC Early CMS Physics22 TAMU Activities  Lepton+Tau Trigger for Z   (for Calibration) : Chi-Nhan Nguyen  Tau Energy - Expanding the CDF experience : Andrey Elagin  MET+Jet Trigger & Sample : Adam Aurisano, Michael Weinberger  MET correction with tau : Alfredo Gurrola, Chi-Nhan Nguyen  M eff Study with tau : Jonathan Asaadi, Alfredo Gurrola

23. June 8, 2007LPC Early CMS Physics23 Backups

24. June 8, 2007LPC Early CMS Physics24 Appendix 1: Reference Points m 1/2 = 360 GeV M gluino = 830 GeV

25. June 8, 2007LPC Early CMS Physics25 Backups

26. June 8, 2007LPC Early CMS Physics26 Tau 101 – How to Find Tau jet  

27. June 8, 2007LPC Early CMS Physics27 TO FIND THE TAU’S Particle Physics and Cosmology Tau 101 Quiz

28. June 8, 2007LPC Early CMS Physics28 jet   Particle Physics and Cosmology Tau 101 Quiz - Answer

29. June 8, 2007LPC Early CMS Physics29 So far in the laboratories we have seen the particles responsible for 4% of the universe. The upcoming experiments will try to probe the nature of 23 % of the universe: dark matter. Challenge: 73% of the universe is still a major puzzle. Not yet understood theoretically! Conclusion June 8, 200729June 8, 2007Particle Physics and Cosmology TO HELP SOLVE THE PUZZLE OF THE UNIVERSE.