FCC-ee physics zoom meeting -

Christos Leonidopoulos (The University of Edinburgh (GB)) , Matthew Philip Mccullough (CERN)

Topic: General Monthly FCC-ee physics meeting

FCC-ee physics zoom meeting
Zoom Meeting ID
Christos Leonidopoulos
Alternative host
Matthew Philip Mccullough
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30-Aug-21 general FCC physics meeting

Maximum participants: 46
(1) News (Patrick Janot)
Slides: https://indico.cern.ch/event/1060845/contributions/4458482/attachments/2299910/3912047/News_GeneralMeeting_30Aug2021.pdf
* Starting 2nd phase of FCC design study: CERN council has approved FCC technical & financial feasibility study (FCC-FS). Focus is on first stage, ie. tunnel & FCCee. Details of tunnel placement under discussion
* Feasibility study organisation: coordinators are being assigned to different roles (see pg. 6)
* 5th FCC physics, experiment & detectors workshop: February 2022 at Liverpool (both remotely and in person)
* FCC Week 2022: May in Paris
* Several FCC essays submitted to European Physics Journal
* Snowmass: process now restarting
(2) Discriminating models with doubly charged Higgs scalars at future colliders: A case study (Janusz Gluza)
Slides: https://indico.cern.ch/event/1060845/contributions/4458481/attachments/2299713/3911843/FCC_Physics_Meeting_08_2021_Hpp.pdf
* Exploring how doubly-charged Higgs can be used as probe for BSM physics, e.g. LRSM (giving mass to neutrinos) or Higgs-triplet model. Focus here is on 4-charged-lepton channel.
* HL-LHC & FCC-hh suited for different H++ scenarios & CPV effects (see pgs. 24 & 25)
Q (Matthew Mccullough): What about custodial symmetry in HT model?
Answer: is doable in principle, but not considered here in order to minimise assumptions
(3) LFV Z decays at future lepton colliders (Xabier Marcano)
Slides: https://indico.cern.ch/event/1060845/contributions/4467862/attachments/2300010/3912087/FCCeeMeeting_xmarcano.pdf
* FCCee optimal collider for boosted LFV Z decay searches, competitive with low-energy measurements
* Comparison of latest results with sensitivity projections from future colliders on pg. 6
* SM effective field theory allows model-independent analysis. Same operators can also generate low-energy cLFV observables (LFVZD, LFV tau & mu decays)
* Comparison of sensitivity between HL/FCCee/CepC & indirect limits on pg. 14. Future lepton colliders more competitive
* Considered both mu-e and tau-ell channels. Z->mu-e very interesting channel and should be explored to test theory. FCCee significantly extends reach wrt to Belle-II
(4) Searching for lepton flavor violating interactions at future electron-positron colliders (Reza Jafari)
Slides: https://indico.cern.ch/event/1060845/contributions/4491616/attachments/2299615/3911402/FCC_Meeting_Reza.pdf
* 1st and 2nd generation LFV is tightly constrained by several experiments: mu->3e (SINDRUM), mu->e gamma and e-mu conversion.  Couplings to taus explored to much smaller degree
* Exploring LFV couplings using e-tau channel (and hadronic tau decays)
* Four Fermi interactions (w/ scalar & vector types) in Effective Lagrangian
* Statistical combination of search results obtained at different e+e- energies significantly boosts sensitivity (see result summary & comparison with Belle-II on pg. 20)
Q (Matthew Mccullough) : are this & previous talks covering complementary region in models?
Answer: (Reza): in general the two models are using different operators


There are minutes attached to this event. Show them.
    • 3:00 PM 3:30 PM
      News, Q&A and general discussion 30m
      Speakers: Alain Blondel (Universite de Geneve (CH)) , Gavin Salam (University of Oxford) , Patrick Janot (CERN)
    • 3:30 PM 4:00 PM
      Discriminating models with doubly charged Higgs scalars at future colliders: A case study 30m
      Speaker: Janusz Gluza (University of Silesia (PL))
    • 4:00 PM 4:30 PM
      LFV Z decays at future lepton colliders 30m
      Speaker: Xabier Marcano (Technical University of Munich)
    • 4:30 PM 5:00 PM
      Searching for lepton flavor violating interactions at future electron-positron colliders 30m
      Speaker: Reza Jafari (Institute for Research in Fundamental Sciences (IPM))