Underlying event
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In physics, the underlying event (UE) is all what is seen in a hadron collider event which is not coming from the primary hard scattering (high energy, high momentum impact) process.[1]
It was first defined in 2002.[2][3]
Further explanation
Underlying events can be thought of as the remnants of scattering interactions.[4][5] The UE may involve contributions from both "hard" and "soft" processes (here “soft” refers to interactions with low p-T, i.e. transverse momentum, transfer[6]).
These are important both in the simulation of particle experiments (often using event generators); and interpretation and analysis of data so as to filter out the desired signals.[7]
Features
Contents of UE include initial and final state radiation, beam-beam remnants, multiple parton interactions, pile-up, noise.[5]
References
- ^ "Underlying Event – a definitive study by CDF - Collider Blog". Collider Blog.
- ^ arxiv.org/pdf/1101.4155v1.pdf
- ^ A. A. Affolderet al.[CDF Collaboration], Phys. Rev.D65, 092002 (2002).
- ^ Lecture 10: QCD at Colliders, page 20. Particle Physics, Dr Victoria Martin, Spring Semester 2013.
- ^ a b http://www.tifr.res.in/~mazumdar/talks/UEDY_IIT.pdf
- ^ Measurement of underlying event characteristics using charged particles in pp collisions at ps = 900 GeV and 7 TeV with the ATLAS detector, G. Aad et al. (The ATLAS Collaboration).(Dated: February 9, 2011)
- ^ Butterworth, Jon (2006). "Underlying Events" (PDF). ucl.ac.uk. London. Wilhelm and Else Heraeus-Seminar on “New Event Generators for Particle Physics Experiments”