1. 26th June 2007RAL1 Signal and Background Separation in ttH Resham Sarkar Indian Institute of Technology, Kharagpur

2. 26th June 2007RAL2 Introduction:  The backgrounds are  ttjj  Electroweak ttbb  ttbb QCD The Event ttH

3. 26th June 2007RAL3 Variables used: (ref. Janice Drohan’s thesis) combinatorial likelihood chi squared distribution difference of the phi angles of the two top quarks lowest mass combination Higgs scalar sum of transverse momentum of the two top quarks b-tagged likelihood

4. 26th June 2007RAL4 We are yet to try: The lowest-but-one combination Higgs mass The difference in eta between the two jets The difference in eta between the reconstructed Higgs and nearest top-quark......

5. 26th June 2007RAL5

6. 26th June 2007RAL6

7. 26th June 2007RAL7 The likelihood variable This has been designed to do combinatorics in ttH All the backgrounds have 'tt' in them, but they are being rejected

8. 26th June 2007RAL8 The b-tagged likelihood

9. 26th June 2007RAL9 a) b) c) d)

10. 26th June 2007RAL10 The Combinatorial Likelihood The mass window ranges from 90 to 150

11. 26th June 2007RAL11 The b-tagged likelihood

12. 26th June 2007RAL12 The difference of phi angles of the two tops

13. 26th June 2007RAL13 The Higgs lowest mass combination

14. 26th June 2007RAL14 Negativity of ttjj The monte-carlo simulation produces some negative weighted events –These are derived from interference terms Complicates the total, smoothing, taking ratios and other functions

15. 26th June 2007RAL15 Total ttjj33124.7 Total ttbbEW705.188 Total ttQCD5018.53 Total poslep213.277 Total neglep212.551 Selected ttjj399.144 Selected ttbbEW94.0769 Selected ttQCD637.557 Selected poslep43.8454 Selected neglep44.613 The better significance is obtained due to the absence of a mass window

16. 26th June 2007RAL16 The Higgs raw mass has been cut at a value where the total shows a peak i.e. -22 At around a mass of 120GeV the highest number is achieved

17. 26th June 2007RAL17 Shoot all questions towardsBill Thank you