CEPC Simulation: next step & Wish list to the MC Tool

Transcription

1 CEPC Simulation: next step & Wish list to the MC Tool Gang & Manqi 06/05/2014 1

2 Objective: Demonstration of Physics Potential, Optimization of Detector Geometry; 06/05/2014 2

3 SM Higgs observables From 1M Higgs: Direct observables Mass, spin, σ(zh) Branching ratios (b, c, tau, g, W) Branching ratios (gamma, mu) + Branching ratios (Z - gamma) Invisible Branching ratio σ(vvh)*br(h bb) Calculate: width coupling g(hbb), g(hcc), g(htt), g(hww)/γ H, g(hμμ), g(hττ), g(hzz)/γ H, g(hww)/g(htt) 06/05/2014 MC4CEPC@IHEP 3

4 ZH event: requirement on detector Higgs qq, gg Strategy: make all the possible measurements in each different channel and combine the result! ττ, μμ WW, ZZ, Zγ, γγ ll vv qq Z boson decay Final state 06/05/2014 MC4CEPC@IHEP 4

5 CEPC Higgs Analysis: Status di-muon di-electron di-neutrino di-jets di-taus σ(zh) - MH σ(zh)*br(h bb) σ(zh)*br(h cc) σ(zh)*br(h gg) σ(zh)*br(h WW) σ(zh)*br(h ZZ) σ(zh)*br(h ττ) σ(zh)*br(h γγ) σ(zh)*br(h μμ) σ(vvh)*br(h bb) Br(H invisible) -? Br(H exotic)??? Signal with CEPC Full Simulation, Bkgrd with Fast Simulation CEPC Fast Simulation 06/05/2014 MC4CEPC@IHEP 5 Extrapolated from ILC/FCC-ee results

6 Higgs measurement, to do Accomplish all the SM Higgs measurement at Full simulation level & iterate with detector optimization studies; Higgs rare decay analysis BSM: Higgs exotic decay and Beyond Recoil mass method, Model independent tagging of Higgs boson Several SUSY motivated analysis is covered in Pre-CDR (H- >MET + bb, H->4b) New benchmark models Time scale: accomplish in next ~ 18 months. 06/05/2014 MC4CEPC@IHEP 6

7 New designs Detector optimization Changed granularity (no power pulsing) Changed L* Changed VTX inner radius Changed TPC outer Radius Changed Detector Half Z Changed Yoke/Muon thickness Scale the detector size & Integrate dedicated design Changed Sub detector design All Changes need to be implemented into simulation, iterate with reconstruction algorithm adjustment - optimization, physics analysis (Fast Full Simulation) and cost estimation 06/05/2014 MC4CEPC@IHEP 7

8 Design new geometry Reduce TPC Radius by 25% 06/05/2014 8

9 Cost estimation: extrapolate from ILD Thick/Thin Yoke ILD Cost ~ 400 MILCU CEPC detector ~ 270 MILCU ~ 1.6 Billion CNY ~ 3 B CNY for 2 detectors; Without manpower 06/05/2014 MC4CEPC@IHEP 9

10 Higgs recoil Mass & Xsec measurements at different beam energy spread/tpc radius 06/05/

11 Br(H->di photon) 06/05/

12 Detector optimization Based on SM Higgs measurements Steps: Scaling the detector Size Geant 4 Simulation: ready Need validation & adjustment of reconstruction algorithms Dedicated Sub-detector design, integration and validation Need to be iterated with sub-detector R&D efforts Quick monitoring Fast analysis package on key physics plots: to be developed. Understand the geometry dependency: Object level, reconstruction efficiency and measurement accuracy Analysis level: Higgs decay branching ratio measurements, etc Goal: converge to 1 2 benchmark detector design 06/05/2014 MC4CEPC@IHEP 12

13 SM measurements at 250 GeV SM processes at Higgs run: 5*10 6 ZZ 8*10 7 WW 5*10 7 Single Z/W 2.5*10 8 qq... What can we measure, from these free data? W mass, width Neutrino generation A FB (b) R values Rare decay of Z/W & flavor 06/05/2014 MC4CEPC@IHEP 13

14 SM measurements at other c.m.s Z pole: Z boson? Z pole + 10 GeV? WW threshold?... Need Careful evaluation of the achievable luminosity and added value to the 250 GeV Runs 06/05/2014 MC4CEPC@IHEP 14

15 Wish-list Exclusive SM Sample, at GeV, Z pole, and other potentially running point. Standard tool for sample validation 1 group of plots for each channel? With comparison/validation to existing experimental data. Xcheck with different MCTools/Generator. Understand the theoretical error for each channel Modeling of Jet fragmentation ISR Jet charge & Forward-Backward asymmetry measurement EW measurement for ISR return sample at 250 GeV Xsec for various channels Jet Structure ~ Jet energy resolution Differential X sec & fiducial cut for t-channel processes Affect the design of detector forward region 06/05/2014 MC4CEPC@IHEP 15

16 Wish-list Dedicated sample for Systematic control Beam energy measurement Luminosity measurement Flavor tagging Jet structure - Fragmentation: Modeling of gluon production and it's convention to 2 b/c quarks, which will be a non-negligible background for initial b/c-jet QQ sample, an idea test bed Phase space integration with off-shell particles, i.e, sub-decay branching ratios of H->VV*->4 fermion... 06/05/2014 MC4CEPC@IHEP 16

17 pp collisions at TeV Physics potential with 10 9 Higgs, top, etc... Physics potential: Higgs & Beyond, SM background sample, Etc. Detector/complex design/layout Fast simulation Full Simulation tool...?... 06/05/2014 MC4CEPC@IHEP 17

18 Summary CEPC Simulation is responsible for demonstration of the physics potential and optimization of the general detector layout. In the Pre-CDR study, half of the SM Higgs measurements are analyzed. To be covered: All the SM Higgs measurement Dedicated BSM model, Higgs exotic decay oriented Other SM measurements We need exclusive, fully validated SM samples Automatic validation tool Understand the theoretical error Xcheck between different generators 06/05/