Abstract
We present an extension to the jet area-based pileup subtraction for both jet kinematics and jet shapes. A particle-level approach is explored whereby the jet constituents are corrected or removed using an extension of the methods currently being employed by the LHC experiments. Several jet shapes and nominal jet radii are used to assess the performance in simulated events with pileup levels equivalent to approximately 30 and 100 interactions per bunch crossing, which are characteristic of both the LHC Run I and Run II conditions. An improved performance in removing the pileup contributions is found when using the new subtraction method. The performance of the new procedure is also compared to other existing methods.
Highlights
The novel feature of the approach described here is the local subtraction of pileup at the level of individual jet constituents
We present an extension to the jet area-based pileup subtraction for both jet kinematics and jet shapes
The constituent subtraction method operates at the level of the jet constituents and provides both a performance improvement and a simplification compared to existing methods: the precision of the reconstruction of jet shapes is improved as well as the speed of the correction itself
Summary
The novel feature of the approach described here is the local subtraction of pileup at the level of individual jet constituents. In contrast to the area-based subtraction and the shape-expansion method, the constituent-level subtraction is performed particle-byparticle, thereby correcting both the 4-momentum of the jet and its substructure, simultaneously. Massless particles with very low momentum are incorporated into the event such that they uniformly cover the y − φ plane with high density These soft particles are referred to as ghosts and they are most commonly used to define the area of a jet [12] or to perform the shape-expansion correction. An iterative procedure is used to define the scheme for calculating the specified amount of transverse momentum and mass mδ to subtract from each jet constituent. The software for the constituent subtraction is implemented as a part of the FastJet Contrib project [20]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
