HepML project

HEPML is a Unified XML format of information required for Monte-Carlo (MC) simulation in HEP.

Following discussions and agreements at the MC4LHC workshop, HepML is now being developed in collaboration between LCG, CEDAR and several generator authors, with others welcome to join in.

GeneratorSchema

HEPML proposal

MC codes

Project structure

CEDAR HepML and LCG HepML

Talks on HepML

HEPML schemes

The first part of HepML is the unified XML format of event samples simulated by Matrix Element (ME) generators (e.g. CompHEP, MadGraph, AlpGen, GRACE, etc.). At present, each MC generator supports its own output format. Some authors of matrix element tools provide interface codes to pass the events of a particular MC generator to the next level of the simulation (e.g. showering, hadronization, decays in SH generators -- PYTHIA, HERWIG, etc.) which are based on Les Houches Accord I. However, there is still no agreement on a possible unified format to save intermediate MC information to a file.

The most appropriate technology for the unified event format seems to be XML, which provides the possibility to describe the stored information in a very flexible and standardized way. Different MC generators may use the same tag for the description of a physics parameter, or may need to keep specific information (through the introduction of a dedicated tag). In other words, the HEPML format should consist of many possible XML tags which will describe the meta information of MC generation (e.g. theoretical model, physics processes, parameters of generation, cuts, ...) and provides the rules how to read specific information about each event (e.g. four-momenta, QCD scale, color chain, etc.). Possible internal adaption of this representation to the most popular Monte Carlo generators would result in a significant improvement of the Monte Carlo documentation and book-keeping.

HepML interface of ME generator event file SH generator is the first step of HepML project. It is possible to extend HepML as an XML standard to keep necessary information for the different levels of simulation in HEP, from theoretical model to a simulation of detector responds. HepML provides the possibility to use and develop many standard tools for the comparison, validation, graphical representation of the results and create transparent unified interfaces for the different software in HEP on the modern level of Computer science.

GROUP PLANS

Group meetings

Example of HepML LHA I Event File of ME -> SH Level of Simulation