Cross section uncertainty for centrally produced samples

sbakare · March 16, 2026, 2:25pm

Hello!
Is there a way I can get the uncertainty for cross sections of the samples from https://fcc-physics-events.web.cern.ch?

jsmiesko · March 16, 2026, 2:52pm

Hi @sbakare,

our old production system (EventProducer) does not track the uncertainty of the cross sections. The datasets from winter23 campaign have just the cross section value being tracked:

github.com/HEP-FCC/EventProducer

config/param_FCCee.py

24702b74a


      
          'p8_ee_ZH_Znunu_Hcc_ecm240':['ZH ecm=240GeV','Z->nunu, H->cc','','0.201868','1.0','1.0'],             #    Pythia 8.303, noBES (Used 0.201037 before)
          'p8_ee_ZH_Znunu_Hss_ecm240':['ZH ecm=240GeV','Z->nunu, H->ss','','0.201868','1.0','1.0'],             #    Pythia 8.303, noBES (Used 0.201037 before)
          'p8_ee_ZH_Znunu_Hdd_ecm240':['ZH ecm=240GeV','Z->nunu, H->dd','','0.201868','1.0','1.0'],             #    Pythia 8.303, noBES (Used 0.201037 before)
          'p8_ee_ZH_Znunu_Huu_ecm240':['ZH ecm=240GeV','Z->nunu, H->uu','','0.201868','1.0','1.0'],             #    Pythia 8.303, noBES (Used 0.201037 before)
          'p8_ee_ZH_Znunu_Htautau_ecm240':['ZH ecm=240GeV','Z->nunu, H->tautau','','0.201868','1.0','1.0'],     #    Pythia 8.303, noBES (Used 0.201037 before)
          
          'p8_ee_ZZ_llX_ecm240':['ZZ ecm=240GeV','Z(ee/mumu)Z(incl)','','0.1739','1.0','1.0'],
          'p8_ee_ZZ_tautauX_ecm240':['ZZ ecm=240GeV','Z(tautau)Z(incl)','','0.0870','1.0','1.0'],
          
          'p8_ee_ZH_ecm240':['ZH ecm=240GeV','inclusive decays','','0.201868','1.0','1.0'],       #    Pythia 8.303, noBES (Used 0.201037 before)
          'p8_ee_ZZ_ecm240':['ZZ ecm=240GeV','inclusive decays','','1.35899','1.0','1.0'],
          'p8_ee_WW_ecm240':['WW ecm=240GeV','inclusive decays','','16.4385','1.0','1.0'],
          'p8_ee_Zqq_ecm240':['Z/Gamma* ecm=240GeV','hadronic decays','','52.6539','1.0','1.0'],  # Pythia 8.303, noBES (was 53.188 before spring2021)
          'p8_ee_Zll_ecm240':['Z/Gamma* ecm=240GeV','leptonic decays (e/mu/tau)','','13.7787','1.0','1.0'],  # Pythia 8.303, noBES
          
          'p8_ee_ZH_mH-higher-100MeV_ecm240':['ZH ecm=240GeV, vary mH','inclusive decays','','0.201316','1.0','1.0'],  # Pythia 8.303, noBES
          'p8_ee_ZH_mH-higher-50MeV_ecm240':['ZH ecm=240GeV, vary mH','inclusive decays','','0.201673','1.0','1.0'],  # Pythia 8.303, noBES
          'p8_ee_ZH_mH-lower-50MeV_ecm240':['ZH ecm=240GeV, vary mH','inclusive decays','','0.202169','1.0','1.0'],  # Pythia 8.303, noBES
          'p8_ee_ZH_mH-lower-100MeV_ecm240':['ZH ecm=240GeV, vary mH','inclusive decays','','0.20253','1.0','1.0'],  # Pythia 8.303, noBES
          
          'p8_ee_ZZ_Zll_ecm240':['ZZ ecm=240GeV','Z to e, mu, tau','','0.027','1.0','1.0'],

Maybe @lportale can help.

For the samples in new campaigns we plan to track uncertainty of the cross section.

Best,
Juraj

lportale · March 16, 2026, 3:15pm

Hi,

Indeed we are not storing this info anywhere for the winter2023 samples; it seemed somewhat useless in the scope of fastsim studies (from what I can recall, and now quickly checking a couple processes, the uncertainty would typically be sub-permil). If we wanted to access it, we would need to re-generate some test samples, which could be done on a case by case basis. If there are processes/studies for which you think it would matter, we can certainly look into it.

Best,

Louis

sbakare · March 17, 2026, 2:47am

Hi Juraj and Louis,
Thank you both for the context! I appreciate the quick help!
Best,
Shreyas