Higgs b ranching ratios study

1. Higgs branching ratios study Oct. 13 2012 Hiroaki Ono (NDU) ILC Physics WG general meeting

2. Current status of Higgs BR study • Higgs branching ratios analysis publication • Ecm=250 and 350 GeVHbb, cc, gg channel • Submitted to EPJ, now under review… • Detailed Baseline Document (DBD) study • Detector benchmarking study for ILD • e+e-ννh @ 1 TeV branching ratio study • Physics chapter • Update results with Higgs mass of 125 GeV ILC Physics WG general meeting

3. vvh detector benchmarking study e+e-vvhis one of the DBD detector benchmarking process Observable: cross section times branching ratios (σ×BRs) Decay channels: hbb, cc, gg, WW*, μμ Evaluate ILD detector performance at Ecm=1 TeV • Jet energy resolution (Reconstructed Higgs mass) • Jet clustering and reconstruction (with γγ BG overlay) • Flavor tagging performance (b/c tagging) • Tracking performance, momentum resolution (Hμμ) We perform the full detector simulation with latest reconstruction packages in ILD ILC Physics WG general meeting

4. Higgs physics at ILC 1 TeV Higgs mainly produced via e+e-νeνeh (WW-fusion) • Final state only comes from Higgs decay • Hbb, cc, gg (two jets) • HWW* (four jets via fully hadronic decay) • Hμμ (dilepton) γγhadron BG is also overlaid as same as CLIC study ILC Physics WG general meeting

5. Simulation condition Higgs BRs @Mh=125 GeV Higgs signal sample Higgs mass: Mh=125 GeV CM energy: Ecm=1 TeV Beam polarization: P(+-0.8, -+0.2) L=500 fb-1 for both pol. Softwares Detector model: ILD_o1_v05 Simulation: Mokka v01-14-01-p00 Reconstruction: Marlin v01-16-00 • Detector mass simulation was finished • Mass reconstruction is still on-going ILC Physics WG general meeting

6. Hbb, cc, ggchannel • Hbb, cc, gghadronic • Simply final state forms two jets • γγhadron background is also overlaid on signal • Apply forced two jet clustering at firstTry different jet clustering algorithm • Durham (LOI) • kt algorithm (used in CLIC CDR for hadron collider) • R parameter(jet-radius) should be tuned Only check signal samples at this moment… ILC Physics WG general meeting

7. Invariant mass distribution Without γγhadron overlay • w/o BG overlay • w/ BG overlay Invariant mass (GeV) Invariant mass (GeV) • Cut on the angler distribution • Different jet clustering DurhamkT jet algorithm (as same as CLIC CDR) ILC Physics WG general meeting

8. kT jet clustering Dijet reconstruction with γγhadron BG Use Durham w/o BG overlay Optimize R parameter for kT algorithm R=1.0~1.3 looks suitable Check with forward particle before jet reconstruction Invariant mass (GeV) ILC Physics WG general meeting

9. Jet reconstruction with PFO cut Dijet reconstruction with γγhadron BG Set R=1.1 for kT algorithm • w/o BG • w/ BG kT • w/ BG kT (cosθ<0.98) • W/ BG inv. M (cosθ<0.98) Check with small statistics Slightly improve the PFO cosθ cut ILC Physics WG general meeting

10. HWW* channel HWW* (one on-shell W) from Higgs decay HWW*qqqqfully hadronic decay channel is considered Apply forced four jet clusteringEmploy kT algorithm with R=1.0 Jet paring for W1, W2(W1 is on-shell with J1, J2)Select best candidate with minimizing χ2 W2 h W1 ILC Physics WG general meeting

11. Reconstructed masses Mw1 Mw MH ILC Physics WG general meeting

12. Conclusion • We concentrate the studies for DBD • vvH@ 1TeV • Detector simulation has beenfinalized • Reconstruction is now still on-going • Schedule is quite tight but need to finalize by LCWS12 ILC Physics WG general meeting