Simulation and Physics Group Meeting
1. Physics analysis
Yu Bai showed the status and update of several physics analysis.
2. Calo optimization
Calo optimization studies had been focus on the Algorithm polish side.
In terms of Separation, we found the photon clusters could be well separated once their impact position is 2*Cell Size away.
H->di photon and H->gluons are used as benchmark channels to evaluate the calo. performance.
At the default geometry, the Higgs to di photon analysis reaches a sigma/Mean of 1.6% - 2.4%, corresponding to defect free/realistic geometry.
Higgs to gluons reaches an sigma/Mean of 4%.
3. Tracking + vertex optimization
Fenfen gave a report on updates, based on Digitization of VXD and dE/dx study at TPC.
For dE/dx study, the sentance, “the difference between MC and some previous experiments still need understanding”, is confusing.
Mani explained that the dE/dx study is important for electron ID and pi/k separation. Using GEANT4 simulation, we finally got sigma_dE/dx as 2%, with pi/k separation at 3~4 sigma. The previous data results are 2 times worse than our results, so we need more information and comparison to understand these differences.
4. Software
Chengdong reported the updates on software, mainly on performance on new tracking algorithm, new geometry interface and code structure for sensitive detector.
After the talk, people mainly focused on the geometry interface. We decided to set a doodle to have more discussion offline.
5. MC production
The sample, e+e- -> H ->mu mu, is in process.
6. Status report on H->μ-μ+ at CEPC
Zhenwei tried γγ -> 2f + e- + e+ background. Based on the results, Manqi suggested only considering this background for inclusive channel.
7. Delphes for CEPC
Cheng reported DELPHES3 for fast simulation.
Manqi suggested considering jet part in the current cards, merging Gang Li’s codes. Try particle flow cord and compare with the current method.
8. Flavor Tagging optimization
Lianliang reported the updates on optimization of flavor tagging performance.
After the talk, people discussed about the reasonability of choosing jet energy for optimization. It is better to use this variable only in certain situations, such as z boson related events. Also we can consider other variables and we can discuss offline.
9. Silicon Sensor Digitization
Zhigang reported the update on digitization of Si detectors.
For the comparison with silicon detector parameters of different type, we need shared data from other groups. We can contact some related people for help.