The framework Delphes provides a realistic fast simulation of generic detectors in a high energy collider experiment, such as ATLAS and CMS. Connected to the output of an event generator, it allows to test large numbers of models and running conditions, with more realism than simple parton-level analyses and by far less complexity than full simulations.
Delphes includes a tracking system, embedded into a magnetic field, calorimeters and a muon system, and possible very forward detectors arranged along the beamline. The framework is interfaced to standard file formats and outputs observables such as isolated leptons, missing transverse energy and collection of jets which can be used for dedicated analyses. A simplified trigger selection is emulated.
The simulation of detector response takes into account the detector resolution, and usual reconstruction algorithms for complex objects, like FastJet. A simplified preselection can also be applied on processed data for trigger emulation. Detection of very forward scattered particles relies on the transport in beamlines with the Hector software. Finally, the FROG 2D/3D event display is used for visualisation of the collision final states.
The DELPHES package uses the ROOT framework and provides
- routines for reading events in LHE, StdHEP, HepMC or hbook-root file formats
- simple track and calorimeter tower simulation
- deflection of charged particles due to a magnetic field
- reconstruction of high level object (e.g. jets, transverse missing energy, leptons)
- simulation of very forward detectors (e.g. ZDC, RP220 and FP420 at the LHC)
- application of a trigger selection
Moreover, the package contains
- example of a program to perform a user analysis on the output of DELPHES
- possibility of using the FROG event display to visualise reconstructed objects and the chosen detector geometry
Delphes has been developed by Séverine Ovyn and Xavier Rouby from the Université catholique de Louvain, under the supervision of Vincent Lemaitre.
Contact: vincent.lemaitre_AT_uclouvain.be, severine.ovyn_AT_uclouvain.be, xavier.rouby_AT_cern.ch
