2009/12/31 by Matteo Cacciari, Gavin P. Salam, Sebastian Sapeta · 109 citations
Physics and Astronomy · #Event (particle physics) #Event reconstruction #High-Energy Particle Collisions Research #Monte Carlo method #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Range (aeronautics) #Rapidity #Tevatron #hep-ph
paper · pdf · doi:10.1007/jhep04(2010)065
published in Journal of High Energy Physics 2010(4) (Springer Nature) · v1: 40 pages, 17 figures; v2: small textual changes, version accepted by JHEP
openalex publication_date 2010/04/01 · arxiv created 2010/05/06 · arxiv updated 2010/05/07 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The measurement of the underlying event (UE) and its separation from hard interactions in hadron-collider events is a conceptually and practically challenging task. We develop a simple, mostly analytical toy model for the UE in order to understand how different UE measurement approaches fare on the practical aspects of this problem, comparing the traditional approach used so far at Tevatron with a recently proposed “jet-area/median” approach. Both are found to perform comparably well in measuring average properties of the UE, such as the mean transverse momentum flow, but the jet-area/median approach has distinct advantages in determining its fluctuations. We then use the jet-area/median method to investigate a range of UE properties in existing Monte Carlo event-generator tunes, validating the main results of the toy-model and highlighting so-far unmeasured characteristics of the UE such as its rapidity dependence, as well as its intra- and interevent fluctuations and correlations.