Conclusions
- Thanks to Eric G and the Production Dynamics skim we have a huge data sample to compare to MC and can make incisive comparisons of 7 Silver Mode states.
- P and Pt spectra: All MC match Pt beautifully. Pythia 6 is softer than Pythia 5 and is thus a much better match to PK? spectrum.
- Yields of K?, K2?, K3?, Ds?KK?, PK?, D*?(K?) ? , D*?(K3?) ?: Default MC grossly underestimate the relative yield PK?. Need to raise the diQ fraction to 20% to come close. There are still (?25%) problems matching the relative yield of K?, K2?, K3?. The relative yields in Pythia 6 are about the same as in Pythia 5
- The multiplicity , momentum, and particle id of primary vertex tracks: All MC are great matches to momentum, Pt and particle id of primary vertex tracks. Pythia 6 is a much better match to the multiplicity spectrum and multiplicity versus P. The only poorly matched primary vertex multiplicity is for PK?
- The charm-anticharm asymmetry: The biggest problem in production models. We have not found a tune which accommodates observed asymmetry for both mesons and baryons. Default MC (NCR) grossly overestimate meson asymmetries and their kinematic dependence but comes close to matching the asymmetry for PK?. The NCR Pythia 6 is a better match for kinematic pattern of asymmetry in mesons than Pythia 5