1. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 1 Model ID @ 500 GeV Taikan Suehara ICEPP, The Univ. of Tokyo

2. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 2 1.Inert Higgs –WIMP:  I (scalar) –Visible:  ± (scalar) 2.SUSY –WIMP:  0 (fermion) –Visible:  ± (fermion) 3.LHT –WIMP: A H (vector) –Visible: W H ± (vector) Three models All give 2W + 2WIMP fs.

3. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 3 √s = 500 GeV, 500 fb -1 full simulation NO Initial polarization Use same masses for all the models m(visible) = 231.57 GeV, m(WIMP)=44.03 GeV Cross section is normalized (200fb & 40fb). Use W hadronic decay (cut leptonic events) Mass -> production angle calculation Full SM background included Weighted to 500fb -1 Analysis overview

4. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 4 ILD detector & framework ILD detector (ILD00) Vertex: Si pixel (3x2 layers) Silicon Tracker: 4 layers TPC(main tracker) ECAL (0.5x0.5 cm tile, Si/W) HCAL (3x3 cm tile, Sci/Fe) Solenoid (3.5Tesla) Muon detector Event generation (signal, SM background) Full-MC simulation (GEANT4) Hit, MC info(LCIO file) Event reconstruction Tracking Particle Flow Flavor tagging etc. Analysis Stdhep event files Particle information (ROOT tree) Gridによる 大量のjob投入 Event weighting Separation cuts Analysis (mass, angle…)

5. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 5 Signal: JSF/physsim Structure HELAS for helicity amp. calculation BASES for numerical integration SPRING for event generation –Pythia for quark fragmentation –ISR/Beamstrahlung included –~0.1 M events for each process generated Background: SLAC (ILC standard sample) –whizard/pythia for all SM processes –~14 M events in total (80-200 fb -1 for 2/4/6 fermion events, 0.1-1 fb -1 for e  /  events) Event generation

6. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 6 Selection cuts 4-jet clustering (Durham) # Track >= 20 160 < E vis < 400 GeV each E jet > 5GeV |cos  | jet < 0.99 unlike 3jet (y th,3 > 0.001) “qqqq (non-b) + missing” each jet has >= 2tracks no > 25 GeV leptons |cos  | miss < 0.9 sum |cos  | < 2.6 sum b-quark prob. < 1 kinematic fit converged 65 < m W < 95 GeV BG suppression cuts

7. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 7 Selection efficiency IH eff: 59.8%, pur (200 fb): 78.6%, pur (40 fb): 42.3% SUSY eff: 58.3%, pur (200 fb): 77.7%, pur (40 fb): 41.0% LHT eff: 58.9%, pur (200 fb): 78.2%, pur (40 fb): 41.8% Acceptable selection performance

8. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 8 W energy distribution (for mass) MC truth (signal only) Reco (kin-fitted) MC & reco have a good correlation. Difference of shapes (esp.WH) is not used for the discrimination in this analysis.

9. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 9 Mass determination Fitting: 3 rd polynomial x Voigt function (10 params) 1.All 10 params free 2.Fix 8 params (except edge positions): obtain errors of the edge positions

10. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 10 Edge positions from the fit: (MC: 96.32/174.78) Masses (MC: 231.57/44.03) Mass resolution Low edge (200 fb) High edge (200 fb) Low edge (40 fb) High edge (40 fb) IH97.00 ± 0.13 GeV 174.22 ± 0.19 GeV 97.86 ± 0.38 GeV 176.22 ± 0.84 GeV SUSY97.12 ± 0.15 GeV 173.46 ± 0.21 GeV 96.10 ± 0.54 GeV 176.02 ± 0.85 GeV LHT96.94 ± 0.16 GeV 174.39 ± 0.10 GeV 99.56 ± 0.48 GeV 174.67 ± 0.34 GeV Visible (200 fb) WIMP (200 fb) Visible (40 fb) WIMP (40 fb) IH232.28 ± 0.12 GeV (0.12) 43.41 ± 0.58 GeV (0.57) 232.40 ± 0.37 GeV (0.39) 35.42 ± 2.78 GeV (2.23) SUSY232.59 ± 0.13 GeV (0.14) 44.84 ± 0.63 GeV (0.64) 231.04 ± 0.51 GeV (0.50) 41.64 ± 2.63 GeV (2.50) LHT232.18 ± 0.13 GeV (0.13) 43.18 ± 0.52 GeV (0.50) 234.06 ± 0.35 GeV (0.41) 33.91 ± 2.07 GeV (1.56)

11. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 11 Production angle of the visible new particle can be calculated from W directions with masses of new particles and back-to-back assumption. The angle has spin info. but two-fold ambiguity (solution of 2 nd equation) exists. Production angle

12. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 12 The distribution looks reasonable. ~30% of the events cannot be used. (discriminant > 0 events selected) Discriminant distribution

13. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 13 MC & reco have reasonable correlation. Three models seem to be discriminated. 1D distribution 200fb

14. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 14 2D distribution (2 solutions) SUSY IH LHT SMBG Chi-square can be derived using these distributions.

15. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 15 One of the [IH, SUSY, LHT] + SMBG -> ‘Template’ (not randomized) One of the [IH, SUSY, LHT] + (SMBG with Poisson randomization) -> ‘Data’ (for other sample than template) (One of the [IH, SUSY, LHT] + SMBG) with Poisson randomization -> ‘Data (for the same sample as template) Normalization (needed or not?) Obtain difference/sqrt(template) bin by bin Square sum of them -> Chi-square value Chi-square value

16. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 16 Chi-square result (200fb) Data Template IHSUSYLHT IH21810091135 SUSY9552331144 LHT9441323268 Number of bin = 210 preliminary

17. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 17 Chi-square result (40 fb) Data Template IHSUSYLHT IH198219227 SUSY203216261 LHT198311211 preliminary Number of bin = 210

18. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 18 To Do

19. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 19 chi-square value: 392 (w/o stat fluctuation) (cf. 210 bins) after normalization ‘Coefficient’ can be derived? (need comparison with other models) Mass error on angle - MCvsReco IH, reco IH, MCTruth

20. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 20 Plan to make 25 mass points (5 visible mass x 5 DM mass) m(visible): 231.57± 0.1x (error in 200fb) ± 0.xx (error in 40fb) m(DM): 44.03 ± … same Possible in generator level almost impossible in full simulation -> use the ‘Coefficient’ (MC-reco ratio)? Difference of distribution on masses?

21. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 21 Toy-MC? Threshold scan

22. Taikan Suehara, 15 th general meeting of ILC physics (Asia) wg., 2010/05/15 page 22 Distribution of production angle looks reasonable. Three models can be separated well in 200fb – some separation in 40 fb Mass error should be considered –Need some more work (several days?) Threshold scan –Need some more work (a day?) Write a paper (several days?) A dedicated week means a calendar month?? Summary (schedule?)