1. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori1 Status of JetsMET Shuichi Kunori U. of Maryland 18-May-2001 PRS: Physics Reconstruction and Selection HCAL/JetsMET group

2. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori2 HCAL - Jets/MET S.Eno / S.Kunori - Coordinator http://home.fnal.gov/~sceno/jpg/Default.htm Dates: End 2002 DAQ TDR (end 2001 for HLT section) End 2004 Physics TDR Organization: HCAL simulation – Sunanda Banerjee (TIRF) CMSIM/GEANT4/FAST Verify shower model in G4. Calibration & Monitoring – Olga Kodolova (MSU) energy scale of jets, MET, tau -> from detector construction/commission to in-situ calibration. HCAL in ORCA – Salavat Abdoullin (Maryland) readout simulation + … Physics objects with HCAL – Sasha Niketenko (CERN/ITEP) jets, MET & tau

3. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori3 DAQ TDR (P.Sphicas, Nov.20, 2000) For both low and high luminosity We will cover all of these!

4. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori4 Main Issues Many physics analyses require - low E T jets: from top, W, Higgs from WW fusion part of signal background rejection (e.g. jet veto) - High luminosity pile-up energy low ET jets from overlapping events fake jets due to pileup. -   jet - b jet (tag) - Correct energy scale from low E T to very high E T - Better resolution for Jet/MET E T range 20GeV-2TeV

5. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori5 Single Top - Kinematics 0200 -2+2 P T (lepton)  >20GeV <2.5 E T (b-quark)  0200-4+4 20-100<2.5 E T (tagging jet)  0200-4+4 >50GeV 2.5-4.0 M T (l+ ) 00200 >20GeV 50-100 200 MET Measurement of - V tb / top decay properties / background to new physics 250pb

6. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori6 Forward tagging jets & Higgs Couplings measurement Although  (VBF)~  (GF)/3, VBF process may play a big role in measurement of higgs properties in addition to discovery potential.

7. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori7  jet Branching ratios for H + M(H + ) 200 500 1000 1 10 -4 10 -2 10 -4 1   tb 1 prong  decay (  jet)

8. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori8  jets tau jet: narrow (one prong) jet L1/L2: use only calorimeter L1: 0.087x0.087 L2: individual crystal

9. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori9 tau jets at L3 1. Tracks are reconstructed with 3 pixel layers only within a cone given by L2.0 jet axis. 2. Isolation cuts: tracks in a big cone (0.3-0.4) vs. a small cone (~0,1), PT(tr)>1-2GeV gg->bbA(500GeV) (Nikitenko & Kotlinski : cms116 analysis)

10. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori10 Pion Response: Linearity 96’H2 Teast Beam Data CMS Simulation ECAHL+HCAL: Non compensating calorimeter Et 100 GeV E= 3 7 30 82 227 GeV 1.5 GeV 3.0 GeV ET=3 GeV pion in 0<|  |<5 0 3 5h=h= 0200400GeV 1.0 0.9 0.8 P= E=EC +  x H1 + H2 +HO  e/ 

11. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori11 Jet Response and Correction #1 No pileup With pileup Et(corr)=a + b x E T (rec) + c x E T (rec) 2 Et-eta dependent correction for QCD jets (S.Arcelli)

12. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori12 Dijet Mass Resolution Jet energy correction without: 19% with: 14% CMSJET 15% M(bb) in ttH W(jj)Top(jjj) Before correction 15% 16% 21% 22% After correction With pileup No pileup (S.Arcelli & V.Drollinger)(R.Kinunnen)

13. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori13 METMET Corrections Type 1: Jet corr. Type 2: Jet corr. + out of cone corr. Out of cone corr. uses weights for jet(30GeV) corr.

14. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori14 Corrected MET for mSUGURA Jets+MET at low lumi Mean offset 

15. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori15 Higgs mass in bbA, A  2   2j before correctionafter correction (A.Nikitenko)

16. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori16 Jet correction method #2 Jet Corr. #1  x (EC+HC) - corr. for jet energy scale -  depends on jet(Et,  ) Jet Corr. #2  x EC +  x H1 +  x H2 - optimize jet resolution (and jet energy scale) - ,  depends on jet(Et,  ) Optimized weights by #2 0.0<  <0.4 (A.Oulianov)

17. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori17 Jet Correction method #2

18. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori18 Minimize with cmsim. Correction method #3a (single pion) Method #1 resolution linearity 1 10 100 1000 (GeV) 30% 20% 10% 0% -5% -10% 5% 10% (E REC - EIN )/E IN Method #3 #1 #3 (open) 3% (118+3)% (127+3)% Linearity is restored to 3% in 10-1000GeV for single pion! i : longitudinal segmenation (V.Genchev)

19. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori19 Correction Method #3b (single pion) Linearity is restored to a few %. The resolution is Gaussian to a high level of accuracy with ~ NO constant term and a 120% stochastic coefficient (e/h) HCAL ~1.39 (NIM paper) To find e/h for ECAL, measure e/pi at different energies for showers where there is a substantial energy (> 30% of the beam energy) in ECAL. (e/h) ECAL ~1.60 Next: identify em cluster and had cluster in jet using transverse shower shape (in crystals) and reco-ed tracks and apply this to had cluster. 0 100 200 300 (GeV) 0 100 200 300 beam reco  /E linearity resolution 10% 20% 5% 10 100 300 (GeV) (D.Green)

20. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori20 Effect of Threshold on low E T jet and MET Electronics noise and occupancy define the threshold. >> aim at 0.5GeV/tower @ 10E34 Lower threshold is better! (A.Krokhotine) (S.Nikitenko) Jets 35<E T (gen)<45geV MET 0.5GeV 1.0GeV

21. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori21 Front end electronics simulation Updated recently E =  (Signal buckets) i –  (pre buckets) j /n Electronics noise 200MeV/25nsec/ch  500MeV/(3+3) buckets/ch  Looking for better method for energy calculation (S.Abdoullin)

22. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori22 Algorithm for L1 through Offline (1) L1 – calorimeter only (coarse segmentation) Resolution improvement Equalize calorimeter response with simple correction a x (EC+HC), a depends on jet(ET,h) a x EC + b x HC, a,b depends on jet(ET,h) Fake Jets/Pileup jets rejection Threshold cut on a central tower in jets (seed cut) L2 – calorimeter only (fine segmentation) Resolution improvement Better energy extraction from ADC counts Em/had cluster separation using transverse shower shape in crystals Fake jet/Pileup jet rejection Use of transverse shower shape

23. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori23 Algorithm for L1 through Offline (2) L3 – calorimeter plus pixel Resolution improvement Pileup energy subtraction Estimation of energy flow from pileup events using pixel hits/tracks. Fake jets/Pileup jets rejection Vertex information and jet pointing using pixel hits/tracks. Offline – calorimeter plus fully reco-ed tracks Resolution improvement Fake jets/Pileup jets rejection  Jet and MET will be reconstructed with Tracks, EM clusters and HAD clusters.  All tracks down to E T ~ 700MeV have to be reconstructed at 10E34! Physics correction – e.g. correction for IFR/FSR.  In-situ calibration!

24. US CMS Meeting @ UC Riverside, 18-May-2001, S.Kunori24 Long way to go, but promising…