WP G - Generators

The wide physics program of LHCb necessitates the ongoing maintenance and integration of many different event generators.

Mandate

The mandate of the Generators work package (WP G) is to ensure:

  • The maintenance and improvement of the usage of Pythia 8, the reference generator in LHCb for pp collision simulations

  • The integration, support and implementation of new models in EvtGen, the toolkit used in the experiment for the decay of all particles

  • The integration of new decay files for production in compliance with both the EvtGen and LHCb metadata

  • The support for integration and use of specialized generators, e.g. CRMC/EPOS

  • The support for integration and use of generators for specific hard processes, either privately implemented, as BcVegPy or GenXicc, or as available in the HEP community, e.g. Madgraph and POWHEGBox

  • The availability of the necessary generator steering configurations for production

  • To trigger the investigation of generators available in the community and of interest for the physics program of LHCb

  • The alert of the need of retirement, replacement or modernization of generators deployed in the LHCb simulation software due to their obsolescence either in physics modeling or software technology

  • The monitoring of the generators tuning and trigger and support the implementation of new tuning. Provide tuning infrastructure via tools like Rivet and Professor in the LHCb simulation software, ensuring their maintenance and supporting their use

  • The availability of information needed to extract efficiency of the generator phase

WP G also ensures the release management of generators data packages and software tools:

  • DecFiles, with general and users decay files, users should pay attention to POWHEG decfiles

  • LHAPDFSets, with PDF sets used by many generators

  • Data packages for specialized generators, i.e. BcVegPyData, GenXiccData, MadGraphData, PowhegBoxData

  • PGunsData, with parametric distributions for signal generation

  • LbRivetPlugins, with LHCb internal plugin before they are made publicly available

Finally, WP G is responsible for the update of the Particle Table.