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Topic: General Monthly FCC-ee physics meeting
25-Oct-21 general FCC physics meeting
https://indico.cern.ch/event/1086252/
Maximum participants: 33
(1) News (Alain Blondel)
Slides: https://indico.cern.ch/event/1086252/contributions/4567080/attachments/2333791/3977626/news-AB-2021-10-25.pdf
FCC technical and feasibility study underway
Organisation chart on pg. 3 with overview of key activities. Proposed membership of coordination group on pg. 4.
FCC global collaboration WG: several countries formally approached, and engagement meetings being scheduled with additional countries.
Organisation of the PED activities in progress. Coordination group will consist of work package coordinators, chairs of support groups, organisers of monthly PED general meetings, and additional members chosen by pillar coordinators.
Interim report of ECFA accelerator roadmap. FCCee could be more prominent. Short document to be added stressing extend of required R&D for FCCee.
Feasibility study timeline:
- Decision on placement of ring : mid-2022
- High-risk area investigations: mid-23 to mid-25
- Design update for preferred placement: mid-23
- Coherence review (FS-mid-term review): mid-23
- Cost reviews with external review committee: 23-25
New FCC-layout: circumference = 91,173 m (reduced from CDR value of 97 km), leading to ~10% smaller luminosity.
What about impact on hadron collider energy?
Discussed, point is such a small energy decrease won't change the discovery potential.
Events of interest:
- Snowmass 21. Here we could use higher FCC-people attendance
- Linear collider workshop: 26-29 Oct
- CEPC international workshop: 8-12 Nov
- ECFA topical workshop on generators for future H/EWK/top factories: 9-10 Nov
- FCC France workshop (Annecy): 30-Nov - 2 Dec
- FCC Physics, Experiments & Detector workshop: 7-11 Feb 2022 at Liverpool. Attendance limited to 150 participants (first come, first serve).
- FCC Week 2022, Paris: 30-May - 3-June 2022
(2) Natural composite Higgs at FCC and Gegenbauer Goldstones (Gauthier Durieux)
Slides: https://indico.cern.ch/event/1086252/contributions/4567078/attachments/2333784/3977611/durieux-fccmeeting-25oct2021.pdf
Higgs mysteries:
- Why lighter than SM cutoff?
- Why are its couplings SM-like?
Gegenbauer potentials: eigenfunctions of linear renormalisation. They naturally suppress ν/f, leading to SM-like composite Higgs.
Nambu-Goldstone bosons, aka: NGBs. For small symmetry breakings (ie. small masses) model becomes pNGBs.
Tri-linear Higgs self-coupling give distinct predictions, in the absence of top contributions.
Higgs coupling measurements at FCC-ee & top-partner searches at FCC-hh: can probe natural pNGB Higgs parameter space.
(3) Flavour at FCC-ee (Jernej Kamenik)
Slides: https://indico.cern.ch/event/1086252/contributions/4567077/attachments/2333810/3977664/Kamenik_FCC-ee_Flavour_2021.pdf
Comparing FCCee potential with full-dataset measurements from LHCb upgrade & Belle-II.
In some more detail:
- CKM determination. If B(W -> cb) ~ 10^-3, a Vcb measurement of 0.1% maybe within reach.
- CP violation with Delta-B = 2. Significant improvement in measurements, observation of CPV in Bd mixing possible (a_fs).
- Rare b-decays to taus. FCCee can probe SM predictions for B->K(*)tautau
- LFV Z decays. FCCee would improve limits by at least 3 orders of magnitude
- Tau physics. FCCee reduces uncertainties by an order of magnitude.
Effort underway to understand experimental precision for rare decays of c- and b-hadrons, CPV in heavy-quark sector and LFV processes at FCCee.
Less explored areas: flavour studies using top & Higgs decays, spectroscopy, quarkonium. Example: top/Higgs exclusive hadronic decays.
(4) H-> s-sbar with the ILD detector (Valentina Cairo)
Slides: https://indico.cern.ch/event/1086252/contributions/4567079/attachments/2333915/3977841/StrangeTagging_VMMCAIRO_MBASSO_FCCPhysicsMeeting_Oct25th2021.pdf
Studying impact of particle ID & strange-quark tagging in e+e- physics.
Sensitivity to Higgs-strange Yukawa couplings at ILC==> develop strange tagger using ILD@ILC (H->ss and H->cs)
Proposed ILD detector layout on pg. 11.
Multiclassifier tagger: uses NN-based tagger for classifying taggers by flavours. Separation between s and u/s possible with truth likelihoods.
H-> ssbar: assuming 2k fb^-1 collected by ILC in 10 years, this corresponds to 400k Higgs produced, but only 40 will decay to strange quarks. Expected asymptotic significant ~ 0.1 sigma (~ 21 x SM κ_S in kappa framework)
More generally, tagger & analysis strategies applicable to other e+e- machines (and use/analysis cases).