LHC-EW WG: Jets and EW bosons

Monday 11 Jan 2021, 16:30 → 18:00 Europe/Zurich

We will use ZOOM for the meeting:

https://cern.zoom.us/j/98001221614?pwd=VGxhSExlZEMrMUtYMUhRZ3JXOUhCUT09

Meeting ID: 980 0122 1614 (passcode 959106)

 

LHCEWWG Jets+Ew, 11 January 2021

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chaired by Vieri Candelise

 

Discussion on future steps (after 17:35, may have missed some)

• coherent input on testing MC modelling uncertainties
• push to get additional data sets to RIVET for proper chi2
• gitLab repo: https://gitlab.cern.ch/lhcewkwg/lhcewkwg-vjets
• paper by Marek Schoenherr

 

Mikel Medizabal, Intrinsic kT tuning

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s4. Tune intrinsic kT at low DY mass to describe low pT,Z at any DY mass using MC@NLO+P8

s10. Fixed alphaS with primordial kT and ISR pT0ref works best

s11. Not sufficient to describe lowest pT of ATLAS measurement though

s12. 38.8 GeV NuSea tune does not work at ATLAS 8 TeV, and vice versa => energy-dependent intrinsic kT

s14. Recipe to define energy dependent intrinsic kT, starting with 38.8 and 8000 GeV

s15. Result extrapolated to CMS 13 TeV measurement => describes first bin well

 

Hugo: how can one get worse chi2 with more parameters? A: could be local minimum.

• Also possible that just caused by MC statistics. What are best fit uncertainties?

Hugo: should also use higher pT,Z to get parameters overall better. Shower and alphaS affect high end as well, even if intrinsic kT does not. Hannes: goal was to focus on intrinsic kT and it’s pT dependence. The kT energy dependence is not in Pythia yet (although pT0 energy dependence is).

 

Mikko: MC statistics? A: MC 10M, but much more than data. Each set produced from the same LHE file so MC statistics correlated.

 

Hannes: follow up? Vieri: could be presented in the other group as well.

 

Hugo: could we have a common repository to put material into, for each of the three topics, for anyone to upload. Would help to check missing parts and focus work for next 2-3 months.

 

Topic: Jets & EW bosons
Time: This is a recurring meeting Meet anytime

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Meeting ID: 980 0122 1614
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16:30 → 16:50 General discussion on future steps

Speakers: Mikko Voutilainen (Helsinki Institute of Physics (FI)), Vieri Candelise (Universita e INFN Trieste (IT))

16:50 → 17:10 Intrinsic kt tuning

Speakers: Mikel Mendizabal (DESY), Mikel Mendizabal Morentin (Deutsches Elektronen-Synchrotron (DE))

EW-11.01.21_Mikel.pdf

17:10 → 17:30 Benchmark comparisons update

Speaker: Heng Yang (CERN)