General:
- Migration to python configurations (common throughout CMSSW)
- use of Geant4.9.1.p02 version, which contains a number of important bug fixes: addition of Coulomb barrier effect in Bertini cascade model fix of the quasi-elastic scattering in QGS model
- additional fixes (from Geant4 repository, added as patches, will become official soon) for: strange baryons interaction with matter G4Tubs memory cleaning and handling in the destruction of volumes
Main changes and new features:
- Physics processes modeling: new physics list QGSP_BERT_EMV (per tests/conclusions of the Calo Task Force), application of the Birks' law in HCAL and ECAL crystals (L3 parameterization)
- Updates in GFlash, ongoing tuning of parametrized Electromagnetic showers using TB data
- Geometry: Ideal geometry is replaced by Pilot2 geometry ((e.g. no ECAL preshower) for the 2_1_0 production
- Geometry: initialization of geometry is located in a single fragment, all the steps are clean from multiple definitions
- Magnetic field: 3.8T field will be used at the LHC startup (instead of 4T), after extesive validation; the initialization is located in a single fragment, all the steps are clean from multiple definitions
- MixingModule: better handling of memory by loading only needed branches
- Data Mixer: validation and debugging of tracker ongoing, calorimeters are combined at digi level, HCAL has started its checks
- TrackingParticle: all particles are stored in one container, additional methods provided to access separately hits in the Tracker or in the Muon system
- Interface to Generators: p-cut is now used instead of p_t cut; eta cut application reviewed to account for the effective position of the particle; decay chain of long-lived particles entering the detector acceptance is now accepted in full (rather than only 1 level up to an immediate parent)
Major bug fixes:
- No major bug fixes in the CMS simulation application
Known issues:
- Event non-reproducibility at the Geant4 level remains an issue and is under investigation
- Some ROOT I/O related issues remain in MixingModule

Last updated: 26 July 2008 Julia Yarba