Shu's weekly group discussion

Wednesday 2 Sept 2026, 10:00 → 13:35 Asia/Shanghai

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

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

Online Zoom meeting room:

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

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

10:00 → 10:05 Introduction & Announcements

Meeting's note: [Nothing to share here]

 

Announcements:

 

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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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10:05 → 10:10 Status

Speaker: Zhijing Zhang (TDLI, SJTU)

Experimental vs. Simulated Beam Spot.png

Light Output vs. Position for Muons and Alpha Particles.png

SiPM Single-Photon Gain.png

  

[Today's focus:]

[DarkSHINE]:

• Collected and fitted SiPM waveforms at different temperatures. The result show that, at a bias voltage of 54.2 V, the single-photon gain decreases by about 12.98 V·μs for every 1°C increase in temperature.（Because of relatively large temperature intervals, multiple pulses often appear within the same integration window at high temperatures. This makes the peak structure of the charge spectrum less clear and leads to poor fitting results.）
• Learning about particle interactions with matter and their detection mechanisms

[STCF]:

• Simulated the position dependence of the light output for alpha particles and muons in a 28 cm pure CsI crystal.
• Compared the beam spot size at different energies between the experiment and simulation, and set the beam spot in the simulation to match the experiment. The resolution hardly changed, which means that using a point source in the simulation has little effect on the performance analysis.

[Plans:]

[DarkSHINE]:

• Learn a more accurate fitting method for waveforms with multiple pulses within the integration window.

[STCF]:

• The experimental light output changes smoothly, but the simulation fluctuates near the end of the crystal. This may be caused by the aluminum housing. I will add it to the Geant4 model to check its effect.

10:10 → 10:20 Status

Speaker: Kang Yu (TDLI, SJTU)

Groupmeeting1_7.pdf

10:20 → 10:30 Status

Speaker: Linjing Duan (TDLI, SJTU)

Today's focus: 

[ZZy ]:

• Run-3 ZZγ signal sample request
  • Prepared a runnable Run-3 ZZγ JO and completed the 1000-event EVNT generation tests and cross-section calculations at both 13 and 13.6 TeV.

Sample	ECM	Cross section
Run-2 official, Sherpa 2.2.5	13 TeV	1.04 fb
Sherpa 2.2.16, repeated test	13 TeV	0.983 ± 0.035 fb
Sherpa 2.2.16, Run-3 test	13.6 TeV	1.069 ± 0.040 fb

• ZZγ Rivet validation
  • Implemented a Rivet validation routine for the ZZγ sample, using the fiducial selections from the Run-2 legacy note as the reference.
  • Produced preliminary validation distributions using the 13.6TeV ZZy samples, including the cutflow, photon pT, mℓℓZ1, mℓℓZ2, m4ℓ, and other relevant kinematic variables.
• 4ℓγ sample request preparation
  • Submitted an independent Sherpa integration job; Rui's integration job is also still running. We will continue coordinating closely since this request is currently a priority.
  • Once the integration/gridpack step is completed, the subsequent EVNT generation and validation should be relatively straightforward.
• Easyjet framework
  • Set up the basic ZZγ analysis workflow in Easyjet, and a preliminary validation comparison with HGamGamStar has been performed by Matthias.
  • Continuing to refine the framework and adding detailed, easy-to-follow documentation, including a clearer explanation of the current analysis cutflow and implementation.

Plans: 

• Continue the 4ℓγ Sherpa integration and start preparing the JIRA request once the integration results are available.
• Complete the ZZγ signal validation, including both the cross-section checks and the Rivet kinematic validation plots.
• Finalize the first shareable version of the Easyjet ZZγ framework within this week, together with the documentation and current cutflow description, and present the status at the next ZZγ group meeting.

 

10:30 → 10:40 Status

Speaker: Jun Wei Lok (TDLI, SJTU)

comsol contour.png

icepak contour.png

Thermal Simulation Comparison (COMSOL vs. Icepak)

evaluate and cross-validate thermal simulation predictions between COMSOL and ANSYS Icepak under identical boundary conditions

Key Findings

Under identical thermal dissipation power (P=0.0912W) and ambient temperature conditions (T=25C), a temperature discrepancy was observed between the two solvers:

Icepak Predicted Peak Temperature: 31C

COMSOL Predicted Peak Temperature: 35.7C


Plan

Benchmark on Simplified Geometry: Isolate pure conduction, forced convection, and radiation on a simple block model to align material properties and solver settings.

 

 

10:40 → 10:50 Status

Speaker: Zelin Yan (TDLI, SJTU)

[Today's focus:]

• Wlllv analysis: 
  • Change to tight lep ID and ISO and show better data/mc agreement in SR sideband and WZCR.
  • Update xgboost training result with new samples and show good data/mc comparison in  low MVA score SR & WZCR & SR sideband.
• HGTD FELIX Monitoring: 
  • Finish felix-io -> OpcUAFELIXBrigde -> WinCC OA panel workflow chain.

[Next plans:]

• Wlllv analysis: 
  • Update fit result with sys asap, 
  • Update INT note.
• HGTD FELIX Monitoring: 
  • discuss with Alex about AQP signoff.

10:50 → 11:00 Status

Speaker: Bai-Hong Zhou (TDLI, SJTU)

11:00 → 11:10 Status

Speaker: Xuliang Zhu (TDLI, SJTU)

11:10 → 11:20 Status

Speaker: Zhiyu Zhao (TDLI, SJTU)

11:20 → 11:30 Status

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

Exotic Higgs decay analysis

• Prepared some analysis tasks for the internship students for lepton isolation, jet reconstruction, and jet tagging
• Next plan:
  • Work on the EveNet model
  • Started to develop a double-B jet tagger for the merged topology

DarkSHINE

• Make a plan for this semester with Chunxiang for the R&D
• At the moment we are determining the SiPM gain as a function of T
• I had discussed with Rui Zhu and she has some ideas to explore. Currently she is in discussion with Yifan Chen to decide the best idea we can try at DarkSHINE

ATLAS HGTD

• I will participate in the wafer test this weekend

11:30 → 11:40 Status

Speaker: Matthias Tartarin (TDLI, SJTU)

 

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Today's focus: 

[VBS kappa_lambda]:

• Nice momentum last month, following internal and collaboration meetings. Next step already in progress (i.e. adding physical reality into our study to assess its study potential on Run-3 data)

[ZZy]:

• Analysis started last month. We are expecting more contributions and collaborations now that summer break is over (with colleagues coming back from holidays). 
• Linjing's ZZy Easyjet has been validated with plots obtained against HGamGam. Plans to make it available to the team now.

[HIGP]:

• In addition to specific request here and there, a lot of tickets to monitor, due to particular high demands (from every groups) which resulted in an impressive waiting list.

[NEXUS 2026/Hyy*]:

• Slides content is done (covering the public paper's results only). Formatting is the last thing left.

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Plans: 

• [VBS kappa_lambda]: Aiming to keep the momentum to have a solid study-case on this project.
• [ZZy] Work-wise, looking to add a ZZy-friendly version of FastFrames to process Easyjet's outputs. Need careful review at the moment.
• [ssWW] Unfolding results to be shared to our colleagues at USTC, and waiting for pol. samples to start EFT studies.
• [NEXUS 2026/Hyy*]: Finishing the slide formatting, and prepare the talk.

11:40 → 12:35 REU: Undergraduate Research Discussions

11:40 Status (w/ Linjing&Danning)

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

11:50 Status (w/ Haydar)

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

12:00 Status (w/ Matthias&Baihong&Xuliang)

Speaker: Ardijan Lorant Ferati (Eberhard Karls University of Tübingen (DE))

12:10 Status (w/ Xuliang)

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