Underlying event
In physics, the underlying event is all what is seen in a hadron collider event which is not coming from the primary hard scattering process.
It was first defined in 2002.Underlying events can be thought of as the remnants of scattering interactions.
The UE may involve contributions from both "hard" and "soft" processes.
These are important both in the simulation of particle experiments ; and interpretation and analysis of data so as to filter out the desired signals.Features
Contents of UE include initial and final state radiation, beam-beam remnants, multiple parton interactions, pile-up, noise.
