Shu's weekly group discussion

Wednesday 11 Mar 2026, 09:25 → 13:00 Asia/Shanghai

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

点击链接入会，或添加至会议列表：

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

10:00 → 10:05 Introduction & Announcements

Meeting's note: No particular announcements have been made during today's meeting.

Here is an attempt of a template to help make the contributions filling easier:

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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
• [...]

[...]

---

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 → 10:15 Status

Speaker: Kang Yu (TDLI, SJTU)

1. Take the courses on General Relativity, Advanced Statistical Physics and Introduction to particle and nuclear experimental methods. Audit a Gauge Field Theory course.
2. Serve as a teaching assistant in Thermology.

10:15 → 10:25 Status

Speaker: Linjing Duan (TDLI, SJTU)

Today's focus: 

       [CEPC Zvvy nTGC ]:

• Consider the systematics for this analysis. Divide them into signal systematics and background systematics.
• Signal systematics may include
  • theoretical uncertainty
  • luminosity uncertainty
  • detector effects (object reconstruction and identification)
  • energy scale and resolution.
• Background systematics may include
  • background normalization uncertainty
  • background modelling effects.
• Read the nTGC Zννγ theory paper and the Zlly FOP paper as references for the draft.

      [Hyy* ]:

• The lowmass lly background templates for prompt leptons have been produced in the new h004 workspace
• The spurious signal test has been performed with the same setup.

Plans:

• CEPC
  • To apply up/down variations for each systematic source and take the change in yield as the systematic uncertainty.
  • These uncertainties will then be included in the EFT fit as nuisance parameters.
  • Wait for Danning’s fitting results to check possible improvements to the sensitivity.

• Hyy*
  • Study the fake background modelling, mainly from non-prompt leptons.

 

 

 

10:25 → 10:35 Status

Speaker: Jun Wei Lok (TDLI, SJTU)

dlnIdv.png

gain vs V

IV curve.png

Temperature coefficient.png

temprature coefficient

I-V Curve Analysis (Laser On)

Measurement: I-V scans were performed from -10C to 30C with a laser source to stabilize the signal.

Breakdown Voltage Extraction

Method: Applied the Logarithmic Derivative  method: d(ln I)/dV.

T(C)	Vbd(V)
-10	37.30
0	37.70
10	38.10
20	38.50
30	39

 

Temperature Coefficient Calculation

Gradient: The temperature coefficient is calculated at 42.00 mV/C which is very close to the value determine by Linear Extrapolation of Gain vs voltage.

10:35 → 10:45 Status

Speaker: Zelin Yan (TDLI, SJTU)

Zelin_Wlllv_update.pptx

10:45 → 10:55 Status

Speaker: Bai-Hong Zhou (TDLI, SJTU)

2026_03_11.pdf

10:55 → 11:05 Status

Speaker: Xuliang Zhu (TDLI, SJTU)

Finalizing the DarkSHINE positron paper this week; will share with our team to circulate for next week.

11:05 → 11:15 Status

Speaker: Zhiyu Zhao (TDLI, SJTU)

Today's focus: 

DarkSHINE:

• v1.6 analysis
  • Samples with new digitization algorithm were generated. But I found a bug which causes some HCAL variables to be reconstructed as empty. 
  • The bug is fixed. New samples is being regenerated

PhD thesis :

• So far, one chapter (out of seven) has been completed. I have only written the text; during the process I found that some parts need additional material, but I have marked them in the document and will address them together later when I have time.

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Plans: 

• DarkSHINE v1.6 analysis：do more check on the reconstructed variables 
• DarkSHINE ECAL： find a time to discuss with USTC people how to carry out this semester’s work.
• PhD thesis: continue to write

11:15 → 11:25 Status

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

Exotic Higgs decay analysis H->aa->4b

• Completed the lepton removal coming from Z->ll decay
• 
• Tagging efficiency of the b-jet has increased significantly (based on the mumuH->qq,gg model)
• 
• Next step: Need to resolve merged jets for m_a<20 GeV. The idea is to cluster the jet in two "fat" jets and use a jet substructure variable to resolve each into two sub-jets
• Possibly fine tune the b-tagging model

HGTD upgrade

• Participated in the wafer probing test at Fudan university

11:25 → 11:35 Status

Speaker: Matthias Tartarin (TDLI, SJTU)

---

Today's focus: 

[ssWW Analysis]:

• Following last week's issue regarding negative weights after the use of FastFrame (cf left plot), Baihong suggested a quick fix until the new samples produced with Easyjet are ready (cf right plot):

            (left)            Weight for the variable M_jj (WZ QCD bakcground)                      (right)

 

• This allowed to test the code developped during past weeks :

                                        (left: My plot)                                                               (right: from Legacy analysis paper ATL-COM-PHYS-2021-999)

which is quite different from the behavior presented by the legacy analysis (see plot at the right). But it is expected: We are using Run-3 pseudo-data, and with undefined 3rd lepton scale factor.
 

• On the subject of Run-3 pseudo-data, I used Baihong's cloned easyjet project, to produce the new mc23 samples : 147 files (140: done; 5 broken; 2 finished). 
  Investigating the broken one, and built an automatic script to download the files directly to /lustre/collider/xxx . It works, and is ready to share, if anyone is interested = "No need to have the terminal opened during the downloads".

---

Plans: 

• [ssWW] Continue the production of mc23 samples, and wait for the production of mc20 (by Baihong) to:
  • Compare the total yields to Run2 legacy.
  • Reweight the WZ QCD samples following the legacy analysis method.
  • And to present it to the analysis group.

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11:35 → 12:30 REU: Undergrad Research Discussions

11:35 Status

Speaker: Peixu Teng (SPA, SJTU)

Today's focus:

• Make a simple test on the use of MadSpin.
• Regenerating new samples will take some time.(2->2)
• Some follow-up code has been prepared.

---

Plans: 

• I'll find time to confirm the formula for the signal example.
• Plotting after the samples are generated
• Preparing for detector-level simulation work

11:40 Status

Speaker: Zhijing Zhang (CCNU & TDLI/SJTU)

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Today's focus:

• Learn about the ECAL of STCF from papers.
• Get familiar with the OSCAR ( Offline Software of Super Tau-Charm Facility ) framework.
• Run OSCAR simulation and obtain the response and resolution performance for photons.

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Plans:

• Start the simulation of the beam test (based on OSCAR).
• Compare it with the data obtained from the beam test.

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11:45 Status

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