Login

FCC-ee Electroweak Precision - round table

→ Europe/Zurich
42/3-032 (CERN)

42/3-032

CERN

20
Show room on map
Alessandro Vicini (Università degli Studi e INFN Milano (IT)), Jan Eysermans (Massachusetts Inst. of Technology (US)), Josh Bendavid (CERN), Marc Riembau (CERN), Matteo Defranchis (CERN)
FCC-ee Electroweak Precision - round table
Zoom Meeting ID
65977622729
Host
Josh Bendavid
Useful links
Join via phone
Zoom URL
Hide

Forward-backward asymmetries (bb,cc,ss)
- Analysis done in fiducial volume? With or without makes quite a big difference. Not taken into account, need to think/discuss about it.
- Need to improve jet charge determination and make recipes centrally available. Will do, first focus is on reloading the flavor tagger and calibration.


Hadronic observables at the Z pole at FCC-ee
- Doing hadronic analysis in FullSim is als good to optimize FullSim and PF (e.g. energy resolution in Z->qq events)
- Try to attract more person power? Yes, probably more for the analysis itself rather than technicalities regarding MC generation etc.

Hadronic observables at the Z pole at LEP
- Also look at OPAL/DELPHI datasets, being converted now by the SFT group. Need to follow up on that and the progress.


Flavour violating Z decays
- NTR - discussed already in detail in previous meetings


Flavour tagging optimisation
- Final goal? Answer: goal is to extract Vcb ultimately, but overlap/synergy with next item.


Vcb in WW
- In overlap with previous analysis item, working together
- Fully hadronic final state needs kinematic fit


W mass in 4-jet channel
- How is the kinfit implemented, in FCCAnalysis/C++? Currently, a python code based on trees from FCCanalysis
- Fourth jet not well reconstructed w.r.t. parton level. The definition of the parton could be the issue
- Related comment: good to simply check reco jet momenta, pairing them with chi2, and check the pair invariant masses


W mass in lnuqq channel & WW threshold scan
- Kinematic fit at 157 GeV more as proof of principle (not enough stats) that it also works close to the threshold. Important for the combination of all energy points to treat all consistently.
- ISR at higher energy to be checked
- Color reconnection only for full hadronic final state (not for semileptonic)
- BES implemented as Gaussian constraint, sqrt(s) scale (~300 keV) not implemented yet
- sqrt(s) = 300 keV from RDP, not yet implemented (now delta function) --> probably negligible but need to be checked


Center-of-mass and luminosity calibration
- NTR


Alpha_QED
- Going to 10e-5 precision, all effects for electron reconstruction to be taken into account (e.g. photons from hard brem)
- Off peak measurement, what is the meaning of alpaQED(mZ) when dealing with off-peak points? (Vicini)
- On peak measurement: tree level clean, simple EM coupling. But beyond tree level needs to be understood also off peak (Vicini)


Alignment and calibration
- Need to implement common alignment tools (check e.g. tools done in CMS)


KKMC-ee developments
- In general, authors of MC programs should be in more connection with experiment for code availability, modern compilation, etc. More to use the tool rather than implementing new physics.


Z lineshape
- Can use pseudo observable as baseline and setting up the framework (till better approaches are developed, but longer timescale)

 

 

There are minutes attached to this event. Show them.