Low Energy Electromagnetic Physics Use Cases and PhysicsLists Maria Grazia Pia INFN Genova on behalf of the Low Energy Electromagnetic Working Group http://www.ge.infn.it/geant4/lowE/

Use cases The most recent use case of Geant4 LowE encountered: X-ray fluorescence generation in ALICE (for detailed detector calibration studies) Known areas of application (in alphabetical order): Astrophysics experiments Cosmic ray experiments Dosimetry Fine arts HEP experiments Medical physics and radiodiagnostics Neutrino and dark matter experiments Nuclear physics experiments Radiobiology Radioprotection Space science etc.

Guidance to address use cases Through advanced examples

PhysicsLists No user has ever asked us for a PhysicsList Users often ask us what is the difference between standard and LowEnergy processes >99% of the users who have asked me the difference between standard and lowenergy had not read the related chapters in the Physics Reference Manual User statistics collected since September 2000 We address this question by working at a quantitative validation of all EM physics models Document the difference of behaviour/precision/performance in an objective way Provide guidance to users through a scientifically rigorous documentation Selecting a LowE/standard process in a PhysicsList is trivial Documented in the Application Developer Guide

Transparency Since the very beginning of RD44, transparency of physics has always been an essential requirement and a distinctive characteristics of Geant4 Is Geant4 faithful to the original spirit of its physics? We give priority to investing the available [limited] resources to make physics more transparent rather than to make it less transparent or to mask an intrinsic lack of transparency