ILD Detector Optimisation Meeting (former software/analysis meeting)

Wednesday 30 Sept 2026, 14:00 → 16:05 Europe/Zurich

zoom coordinates to be distributed by email!

14:00 → 14:10 Physics coordinator report

Speakers: Taikan Suehara (ICEPP, The University of Tokyo), Graham Wilson

Physics coordinators report, 30 Sep. 2026

• LCWS2026@KEK, Nov. 9-13 https://agenda.linearcollider.org/event/11000/
  • Early registration deadline, 4th Oct.
  • Abstract submission deadline passed, some sessions may still have slots to accept. Contact conveners.
• FCC-PED general (monthly) meeting, Oct. 1 https://indico.cern.ch/event/1733820/
  • Each WG has meetings: check https://indico.cern.ch/category/5251/ or subscribe appropriate mailing lists.
• Coordination of this meeting
  • Start to officially include hardware activities: Software/Analysis meeting --> Detector Optimisation meeting (revival of original name)
    • This meeting is mostly non-strategic: a place to present ongoing studies
      • More casual than FCC meetings: intermediate results/status can be shown
      • Also continue to welcome LC-related studies!
    • More strategic coordination will be on ILD monthly meeting
      • Frequency may be reduced (maybe with longer time?): under discussion
  • Keep biweekly Wednesday 2pm in European time if no serious conflicts
    • Select weeks to try to avoid overlap with FCC analysis tools/MC production meeting (which uses the same slot)
  • Add technical coordinators report
• Summary of the analysis talks at the ILD meeting at CERN (by AI)

  • Summary of the ILD physics activities in recent years — Aleksander Filip Zarnecki (University of Warsaw)
    Reviewed the main ILD physics activities carried out in recent years and provided an overview of the current status of the analysis programme, setting the context for the future physics activities discussed in the following talks. 線形衝突器議事録

  • Plans and targets for ILD in coming years — Taikan Suehara (ICEPP, The University of Tokyo)
    Presented possible directions for the future ILD physics programme, covering FCC-ee studies, high-energy linear-collider physics such as double-Higgs and BSM searches, and physics-driven detector optimisation. Updating key analyses using modern AI-based reconstruction and strengthening coordination with FCC-ee physics activities were highlighted. 線形衝突器議事録

  • Z-pole studies with ILD — Graham Wilson (The University of Kansas)
    Reviewed the main electroweak measurements possible with the enormous FCC-ee Z sample, including the Z lineshape, asymmetries, branching ratios and tau polarisation. The emphasis was on controlling systematics—luminosity, centre-of-mass energy, acceptance, efficiency and backgrounds—rather than simply improving detector resolution. 線形衝突器議事録

  • Plans from the FCCee physics studies group — Michele Selvaggi (CERN)
    Introduced the FCC-ee Physics Studies programme and the activities planned during the 2026–2028 Reference Design Phase, where important physics benchmarks need to be demonstrated with full simulation. The talk discussed common ground with existing ILC/ILD studies, new opportunities at the Z pole, detector requirements, and how the ILD community can contribute to the FCC studies. 線形衝突器議事録

  • Higgs hadronic branching ratio studies for LC and FCCee (incl. PFA performance with ILD-FCC) — Ryu Sawada (University of Tokyo)
    Presented several ongoing Higgs studies using improved jet-flavour tagging, including measurements of \(H\to b\bar b,c\bar c,gg,s\bar s\) at the ILC, a search for \(H\to bs\), and the first \(H\to s\bar s\) studies with ILD at FCC-ee. Particle Transformer with particle-ID information significantly improves some channels, while further work is needed for charm and strange tagging and for validating the ILD-FCC reconstruction performance. 線形衝突器議事録

  • Status on ZHH analysis — Julie Munch Torndal (DESY/UHH)
    Presented the ongoing re-analysis of double-Higgs production with ILD at 550 GeV for a direct determination of the Higgs self-coupling. The lepton-channel analysis has been further improved using a multiclass XGBoost classifier, while the neutrino channel now explores the separation of ZHH and W-boson-fusion HH production below 1 TeV; direct extraction of the Higgs self-coupling and the re-analysis of hadronic channels are ongoing.

  • Higgs CPV analysis in tth coupling at 550 GeV LCF — Yuyang Zhang (University of Glasgow)
    Presented a study of the magnitude and CP structure of the top-Higgs Yukawa coupling using \(t\bar tH\) events at 550 GeV. Modern reconstruction with ParT and kinematic fitting gives about 2% precision on the top-Yukawa strength in the semileptonic channel, while an ML-based CP observable gives a preliminary constraint on the pseudoscalar component, with further improvements under development. 線形衝突器議事録

  • Towards a Higgs to Invisible Analysis at ILD@FCC-ee — Victor Schwan (DESY)
    Presented the first steps toward an \(H\to\) invisible analysis with ILD at FCC-ee, which also serves as an integrated test of the new simulation and reconstruction chain. Particular attention was given to combining TPC and silicon tracking, track merging, and the first fully Gaudi-based reconstruction of the Higgs recoil mass. 線形衝突器議事録

  • Z→ττ: Reconstruction and preliminary tau polarization studies at FCCee — ILD vs CLD — Olmo Arquero Peinazo (CIEMAT)
    Compared \(Z\to\tau^+\tau^-\) reconstruction with the ILD and CLD detector concepts at FCC-ee and presented preliminary studies of the tau-polarisation measurement. The analysis provides a useful benchmark for understanding how detector and reconstruction performance affect precision tau physics at the Z pole. 線形衝突器議事録

  • Summary of exotic scalar searches — Aleksander Filip Zarnecki (University of Warsaw)
    Summarised recent ILD searches for additional light scalar bosons at 250 and 550 GeV, including decay-independent recoil searches and dedicated \(S\to b\bar b\) and \(S\to\tau\tau\) analyses. The decay-specific searches provide strong additional sensitivity, and the combined studies cover scalar masses up to near the kinematic limit; the analyses are now being finalised for publication.

 

14:10 → 14:20 Software coordinator report

Speakers: Thomas Madlener (Deutsches Elektronen-Synchrotron (DE)), Leonhard Reichenbach (CERN / University of Bonn (DE))

Leonhard Reichenbach will serve as Deputy SW convener

Uli Einhaus will serve as reconstruction SW convener

Other positions still to be filled / under discussion

 

ILD is formally part of the FCC study so we are able to use FCC resources for related studies. A large(r) scale production is planned for fall. Sample requests are still being taken. Let us know if there are special wishes. We will need to validate reconstruction before the start of the production in order to be included(!).

 

Sample request site: https://fcc-drs.web.cern.ch/

14:20 → 14:30 Technical coordinator report

Speakers: Vincent Boudry (Laboratoire Leprince-Ringuet, CNRS/IN2P3, École polytechnique), Karsten Buesser (DESY)

2026-09-30@ILD-Optim_TechCo_VBY.pdf

14:30 → 14:50 discussion time