Shu's weekly group discussion

Monday 19 Oct 2026, 15:30 → 19:05 Asia/Shanghai

Tsung-Dao Lee Institute/N6F-N630 - Smart Classroom (Tsung-Dao Lee Institute)

Haidar Mas'ud Alfanda (TDLI, SJTU), Matthias Tartarin (TDLI, SJTU), Zhiyu Zhao

Online Zoom meeting room:

https://cern.zoom.us/j/4042031778

(PIN protected, see message from the group chat announcement)

15:30 → 15:35 Introduction & Announcements

Meeting's note: []

 

Announcements:

Conferences:

• The 2026 International Workshop on the High Energy Circular Electron Positron Collider (CEPC2026)
  • Oct 21 – 26, 2026
  • Jiading, Shanghai
• The 12th China LHC Physics Conderence（CLHCP2026）
  • October 28, 2026 to November 1, 2026
  • Wuhan

 

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Today's focus: 

[1st project/analysis: XXX ]:

• item 1
  • sub-item 1
  • sub-item 2
• item 2
• [...]

[2nd project/analysis: XXX ]:

• item 1
• item 2
• [...]

[...]

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Plans: 

• [optional: indicate which project/analysis it refers to] item 1
• [optional: indicate which project/analysis it refers to] item 2

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15:35 → 15:45 Status

Speaker: Zhi Wang (TDLI, SJTU)

15:45 → 15:55 Status

Speaker: Zhijing Zhang (TDLI, SJTU)

15:55 → 16:05 Status

Speaker: Kang Yu (TDLI, SJTU)

1.  [PhD qualifying exams]
   
   1.  Finish the written examinations
   2.  To-do: Finish a research report
2.  [VBSZZ CP task] 
   1.  Get familiar with the code for computing electron isolation scale factors shared by Evan
   2.  To-do: Discuss more details in a meeting today

16:05 → 16:15 Status

Speaker: Linjing Duan (TDLI, SJTU)

Progress

ZZy

• Reviewing and updating the JOs based on the MR discussion threads, checking the integration settings, and preparing clarifications to support Danning in moving the MR towards approval and merge.

HGTD

• Set up and compiled the offline fitting farm on lxplus. Studied VTH, VTHC and Charge scans; currently learning the S-curve fitting functions.

• Plan to draft an AQP status mail and send it to Alex for discussion at our next meeting, with offline sample analysis and toy-scan validation as the next steps.

 

Plans

ZZγ

• Prepare a short presentation on the Easyjet framework for the group, summarizing the current implementation, key choices made and remaining open points for discussion.

Hγγ*

• Finish the CLHCP poster on merged-electron identification and performance

16:15 → 16:25 Status

Speaker: Jun Wei Lok (TDLI, SJTU)

A comparison between the experimental and simulated data reveals a consistent trend: the simulated temperatures are systematically higher than the actual measured temperatures. This discrepancy can be attributed to limitations within the simulation model and inherent heat-loss factors in the experimental measurement setup.

1. Simulation Limitations (Two-Resistor CTM)

• Averaging Error: The model represents the package surface as a single thermal node. This ignores actual temperature gradients and leads to overestimated case temperatures.

• Low Absolute Accuracy: It has poor predictive accuracy (≤30%) for absolute temperatures, making it better suited for relative design comparisons rather than exact measurements.

2. Experimental Inaccuracies

• Heat Sinking Effect: The thermocouple acts as a physical heat sink, drawing heat away and artificially cooling the exact spot being measured.

• Setup Errors: Using improper attachment methods (e.g., taping) worsens this heat loss, potentially reducing the measured temperature by up to 50%.
  
  

16:25 → 16:35 Status

Speaker: Zelin Yan (TDLI, SJTU)

[Today's focus:]

• Wlllv analysis: 
  • Finish BDT, systematics, statistical analysis section in INT note. 
  • Add parton shower uncertainties into fit with ~2% variation.
  • Add tt+X sample into fit(some contribution).
• Others: 
  • Prepare for the fourm for Intedisciplinary & innovative Research, held by SJTU.

[Next Plans:]

• HGTD Upgrade: 

  • Prepare a detailed inventory of the equipment received from CAEN before setting up the LV-PS production test in middle November with Olivier

  • Investigate register write/control through FELIX I/O and the OPC UA server.
• H2a4b analysis: 
  • Investigate the data/mc mismatching in Z+jets CR 2024 dataset.
  • Construct ttbar CR. 

16:35 → 16:45 Status

Speaker: Baihong Zhou (TDLI, SJTU)

[ssWW]:

• Pushed ParT model to FastFrames.
• Discussed with John, Matthias and Siddharth for the next step's plan.

[Boosted HH to 4b]:

• Statistical FW migration(from one specific FW to the common one which has been used in all HH4b analysis).
  • Validated the histogram generation step. -> Same histogram has been obtained.
  • Began to migrate the workspace generation.

[Others]:

• Prepared the presentation for the JiaoChang PhD Student Forum.
• Prepared the poster for the calibration of Xbb tagger for CLHCP 2026.

 

Plans: 

[ssWW]:

• Check the workflow for ParT.
• Investigate if some other statistical strategies can improve the sensitivity.

[Boosted HH to 4b]:

• Finish the statistical FW migration.
• Investigate to JO for CHResonance samples.

[Xbb calibraiton]:

• Add the 2025 and 2026 samples and trigger list to easyjet.

[Others]:

• Finish the poster for the calibration of Xbb tagger for CLHCP 2026.
• Talk with Tancredi for the jet energy related study in the forward region.

16:45 → 16:55 Status

Speaker: Xuliang Zhu (TDLI, SJTU)

16:55 → 17:05 Status

Speaker: Zhiyu Zhao (TDLI, SJTU)

[STCF EMC CsI crystal test]:

• Designed four-channel SiPM array readout boards and submitted it for fabrication to test timing and charge measurement precision. The submitted board supports 5 different circuit configurations for comparison.

• The temperature-controlled chamber doesn't work. We contacted the manufacturer, and they will come to repair it this week.
• Plans:
  • Waiting for the boards to be fabricated and the temperature-controlled chamber to be repaired, followed by testing.

 

[DarkSHINE ECAL prototype]:

• Updated the mechanical design and sent it to the USTC people

• Plans：
  • Waiting for the USTC team to complete the front-end electronics design before conducting the tests

 

17:05 → 17:15 Status

Speaker: Haidar Mas'ud Alfanda (TDLI, SJTU)

DarkSHINE

• Compared the cross section of fermionic DM obtained using MG5 with analytical calculations: Weizsäcker-Williams (WW) approximation, improved WW (IWW) and exact tree level (ETL). An example for millicharged particle (MCP) is shown in the figure below.

• Found that the integration by MG5 has a very large error (~47%), which means the integration failed to converge. Tired several strategies for the integration with no success.
• Thus, MG5 cannot be trusted for the fermionic DM. In the DSS we will use the cross section and kinematics obtained using the ETL method to implement the LUT and limit evaluation.

 

ATLAS HGTD

• Participated in a wafer test last weekend
• Preparing the poster for CLHCP

17:15 → 17:25 Status

Speaker: Matthias Tartarin (TDLI, SJTU)

 

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Today's focus: 

[ZZy]:

• FastFrames has been finished last week. Should already be ready to be shared to the group. Regions are taken from Run-2, but the analysis team can define their own configs after.
• Internal discussion should have happen by the time I read this sentence. Objectives for the short and long term should have been discussed with Rui and Linjing. Will discuss with Kang quickly too about his contributions with the CP.

 

[ssWW]:

• Work done last couple of days on the common ssWWjj_FastFrames branch for both Easyjet and VBSTool from Baihong's branch. Merge request passed, we should now have single branch for both frameworks which would coherently propagate any changes made by one team to the other. Waiting for Baihong's potential remarks before informing the analysis team.
• Unfolding implementations in ssWWjj_FastFrames progressed well. But not yet ready for it to be merge. 
  
  

[VBS_KappaLambda]:

• Pheno. study on the ssWW analysis (Run-2 and Run-3, CMS and ATLAS) is well advanced. On stand-by for now.

 

[HIGP Derivation]:

• Quite demanding on very specific (new) tasks, without much documentation to help.

 

[WWW review]:

• Already covered some sections of interest from the newly available INT Note. Will draft comments more clearly by Friday.

 

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Plans: 

• [Full Run-3 Hyy*]: Will focus on the merged electron ID studies again.
• [VBS_KappaLambda]: Should probably present current results formally, and discuss the next steps/directions with the group.
• [ZZy]: Main work direction on the week(s) to come. 
• [ssWW]: Continuing implementing the unfolding strategy in ssWWjj_FastFrames. When done, will perform validations and will present them to the analysis group. Also, more long term directions to be organised and discussed internally this week.
• [WWW review]: Prepare the organised comments by Friday.

17:30 → 18:25 REU: Undergraduate Research Discussions

17:30 Status (w/ Linjing&Danning)

Speakers: Bingxian Li (SPA, SJTU), Jiacheng Shi (SPA, SJTU), Yuning Chen (Zhiyuan College, SJTU), Zhengyang Qian (SPA, SJTU)

17:40 Status (w/ Haydar)

Speakers: Hansheng Ye, Mingyu Huang (Univ. of Manchester (GB))

17:50 Status (w/ Xuliang)

Speaker: Hongyi Chen (University of Nottingham, Ningbo, China)

18:00 Status

Speaker: Jing Li (Fudan Univ. (CN))

[Graduation Thesis Project: 2HDM-a Dark Matter (l + MET)]:

• Project Goal: Investigate experimental signatures and evaluate expected sensitivity at the LHC for the 2HDM-a model with a non-degenerate mass spectrum.

• Established full Monte Carlo simulation chain (MadGraph + Pythia8 + Delphes) for signal event generation.

• Validated 4-lepton final state: Successfully reconstructed the invariant masses of the two Z bosons, confirming correct event identification.

• Performed parameter scan: Conducted a one-factor-at-a-time scan on mA, ma​, tan⁡β, and sin⁡θ.

• Quantitative kinematic analysis:

  • Employed the Kolmogorov-Smirnov (KS) test to evaluate the impact of the non-degenerate mass spectrum.

  • Preliminary results indicate that m4l and pT4l​ are highly sensitive to parameter variations.

  • 

• Ongoing task: Currently generating background samples to evaluate the expected experimental sensitivity.

• [Others (Thesis related)]:

• Preparing the Thesis Proposal  for the graduation thesis.

•