Physics of shower simulation at LHC, at the example of geant4

Abstract

The LHC experiments will explore new frontiers of particle physics, and open new ways for experimental research in high energy and nuclear physics. To maximize the physics potential of LHC, we need simulation of lepton and hadron interactions and cross-sections in the collider, shielding, and detectors. We need to be able to predict both the detector responses, and the radiation environments in the context of the planned machine operation scenarios. This can be realized through detailed simulation of the paths of particles traversing the materials of the experimental set-up. The experimental conditions posed by the LHC, which will be operating at higher energy, luminosity and precision than the present colliders, are very demanding. Triggered by this challenge, the physics modeling of interactions of leptons and hadrons with nuclei, and the associated final state generators and cross-section calculations, have seen significant advances both on the theoretical and technical level during the last few years. We will discuss the methods of physics in particle transport, and review recent advances at the example of the GEANT4 simulation tool-kit, that was built for the LHC experiments. The focus will be on soft hadronic and nuclear physics.