RRT: BSM & Dark Matter (collider & beyond)

Name: RRT: BSM & Dark Matter (collider & beyond)
Start: 2025-07-10T15:00:00+02:00
End: 2025-07-10T15:59:00+02:00
Location: No location set

Thursday 10 Jul 2025, 15:00 → 15:59 Europe/Zurich

Description

https://desy.zoom.us/j/69434264047

Meeting ID: 694 3426 4047
Passcode: 314159

- 15:00 → 15:55
  What is missing in the PPG’s representation of the LC BSM / Dark physics case? 55m
  
  Speaker: All
  Notes from meeting:
  
  Two categories of problem:
  - LC lines missing in plots that have been chosen
  - choice of plots tends to play down e+e- and particularly high energies
  
  We agree that 3TeV CLIC results should be included - briefing book should reflect complete state of scientific knowledge.
  
  From Rebeca's talk
  https://agenda.infn.it/event/44943/timetable/#20250626.detailed
  
  slide 5, Y-Universal Z' - where does LCF 500 line come from? - are luminosities correct for LC lines? Should be updated with latest EFT fit, and 550. (Roberto)
  
  slide 6, Le-Lmu - choice of model is surprising (but FCC-ee published paper in March). The "HET mono-gamma" is supposed to be a LC study projected on to this model; only 250. But there is a full simulation study at 500GeV, also extrapolated to 1TeV, and CLIC also has a mono-photon study at 3TeV. (Filip has UFO from Roberto, can have results in muon-gamma channel in a few weeks.) Need to check where 4-fermion lines come from (final state? contact interaction?), but strange that there is no LC line between FCC-ee and MuC 10TeV.
  Filip will try to collect mono-photon results.
  Jenny will look for 500GeV full sim study.
  
  slide 8, composite Higgs - LCF500 to be updated to 550
  slide 9, composite Higgs - 3TeV missing CLIC study is http://arxiv.org/abs/arXiv:1812.02093 Fig 35
  
  slide 10, RG-improved
  We think these are very simplified models; need to understand assumptions.
  Not clear what LCF means - Z-pole? CoM energies should be given
  CLIC study is http://arxiv.org/abs/arXiv:1812.02093 Fig 35, 36, 37
  Roman will dig deeper into this one.
  
  slide 12, real scalar singlet
  All LCs missing
  indirect constraints come from Higgs couplings fit, should be added for all LCs
  CLIC has resonant search, should be added
  
  slide 13 Higgs potential
  CLIC is missing. LCF should give CoM energies.
  Sven/Georg should take the lead on this one
  
  slide 14 first-order phase transition
  Georg should comment. Narrow correlation is not seen beyond Leading Order?
  LCF energies should be given.
  
  slide 15 first-order phase transition
  No lines at all for e+e- ?
  Was this in Shinya's talk from January?
  
  slide 17 wino, and slide 18 higgsino
  LCF 250, 550 should be added
  CLIC 3TeV should be added, http://arxiv.org/abs/arXiv:1812.02093 Fig 74
  Should be made clear that disappearing track results are much more model-dependent than the rest
  
  slide 20 - leptoquarks
  Should the models be more general?
  Theorists may want to comment.
  
  slide 21 flavour deconstructed models
  LCs have many Z' limits -- either they are missing, or the model here is particularly carefully chosen
  Should be as good as FCCee ee->ff, and polarisation could gain
  Perhaps Juergen could have a deeper look?
  
  slide 24 SUSY etc
  Mikael will take a closer look
  Sleptons should be added
  
  slide 25 top partners
  what constraints would come indirectly?
  
  slide 27 dark photons
  CEPC line is old theory estimate that is wrong
  FCC-ee may come from the same source?
  Mikael may be able to do a simple rescaling of LCF results to higher energies
  Beam dump area of plot - e+e- colliders are completely missing (Ivo)
  
  slide 30 HNL
  should include lines from Juergen/Filip/Krzystof's study
  
  NEXT steps:
  
  Jenny notifies “scenario responsibles” not present
  
  each “scenario responsibles” collects immediate comments by the weekend
  
  Jenny provides overleaf skeleton, "scenario responsibles” there topics
  
  first snapshot to PPG early next week with straight-forward comments
  
  prepare more comprehensive view as well => updated dedicated note AND LCVision-Generic document
  
  comment&question by Mikael:
  
  I have a comment and a question on the plot on dark photons that you showed in your presentation on Monday (slide 6, and slide 11):
  
  You say that the curve for CEPC comes from Karliner &al (arxiv:2207.06307). This result is simply *wrong* - it is based on a much too naive view on how this kind of signal can be measured in any kind of collider detector, details in the ECFA-HEP report CERN-2025-005 (arXiv:2506.15390) p. 234-236. The curve should not be shown - CEPC could be asked to give an update.
  
  The question is how you did the extrapolation of LHC to HL-LHC (and FCC-hh)? I see a factor about 3 between LHC and HL-LHC, which i find surprisingly much. LHC to HL-LHC would mean ~10 more statistics, so I would expect the cross-section limit would be sqrt(10) ~ 3 times better, and since the cross-section goes with epsilon^2, the epsilon limit would be the square-root of that, so only about 1.8, not 3. Or am I missing missing something?
  
  comments by Lucie
  CERN-2018-009-M stands for the CLIC yellow report on the CLIC Potential for New Physics: http://arxiv.org/abs/arXiv:1812.02093
  
  Slide 6: Le-Lmu: LCF and CLIC are missing.
  
  Slide 9: Compositeness: CLIC 3 TeV is missing. The corresponding study is documented in CERN-2018-009-M
  
  Slide 10: RG: CLIC is missing. For LCF a label on the used CoM energies is missing. In general the plot is problematic; cannot match colours with facilities.
  
  Slide 12: Scalar singlet: All Linear Colliders are missing. A CLIC study exists, documented in CERN-2018-009-M.
  
  Slide 13: shape of Higgs potential: CLIC is missing. For LCF a label on the used CoM energies is missing.
  
  Slide 14: Scalar singlet: CLIC is missing. For LCF a label on the used CoM energies is missing.
  
  Slide 15: Electroweak Phase Transition: Linear Colliders are missing.
  
  Slides 17/18: Wino and Higgsino: LCF is missing. CLIC 380 and 1500 are shown. As MuCol at 3 TeV and 10 TeV is shown, it makes sense to add CLIC 3 TeV as well. A study exists for CLIC in CERN-2018-009-M (fig. 74)
  
  Slides 20/21: Flavour: LCF and CLIC are missing, but MuCol and 3 TeV and 10 TeV is shown, which seems inconsistent.
  (CERN-2018-009-M addresses flavour issues for CLIC, but I see no overlap with the subjects in Rebeca’s talk)
  
  Slide 27: Dark Photon: Very many facilities are shown in the plot, but LCF and CLIC are missing.
  
  Slide 28: Dark Scalar/Higgs: LCF and CLIC are missing. FCC-ee curve is bizarre => looks like work-in-progress
  
  Slide 29/30: ALP and HNL: LCF(250) is shown, but CLIC is missing.