DeltaRNLO not working properly
The selector DeltaRNLO is not cutting properly on all the possible particle pairs that satisfy the selector flavor requirement; instead it seems to be finding the pair with the largest DeltaR value per event, and cutting only on that pair’s DeltaR.
I noticed this running the integration for pp -> W gamma gamma (with W -> mu nu decay) at NLO, Sherpa 2.2.2. You can find two run cards attached:
- Run_DeltaRNLO.dat: If I use “DeltaRNLO 22 90 0.2 1000”, the integration doesn’t converge. Analyzing the screen output in debugging mode, I realized that events with one photon collinear with the muon, with DeltaR values below 0.2, are still passing the selector.
- Run_UniversalSelectorDR.dat: If I use the DR universal selector “ “DR" 22,90 0.2,1000:0.2,1000 “, instead of DeltaRNLO, the DeltaR cut is applied properly on both photons, and the integration converge successfully.