1. Low Energy Electromagnetic Physics Use Cases and PhysicsLists
Maria Grazia Pia
INFN Genova
on behalf of the Low Energy Electromagnetic Working Group

2. 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.

3. Guidance to address use cases
Through advanced examples

4. 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

5. 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