The anti-ktjet clustering algorithm

Cacciari, Matteo; Salam, Gavin P.; Soyez, Grégory

doi:10.1088/1126-6708/2008/04/063

Cited by 5,819 publications

(5,176 citation statements)

References 24 publications

Supporting

Mentioning

5,151

Contrasting

Unclassified

Order By: Relevance

“…All particles, apart from the isolated electrons and muons, are clustered into jets using the antik T jet clustering algorithm [32] with distance parameter 0.5. energies are calibrated by applying correction factors as a function of the transverse momentum and the pseudorapidity of the jet. The effect of pile-up is reduced by using the FastJet pile-up subtraction procedure [15,16] for data and simulated events.…”

Section: Samples and Event Selectionmentioning

confidence: 99%

CMS Technical Design Report for the Pixel Detector Upgrade

Dominguez¹

2012

View full text Add to dashboard Cite

The original design goal of the LHC was to operate at 1 × 10 34 cm -2 s -1 with 25 ns bunch spacing, where approximately 25 simultaneous inelastic collisions per crossing ("pile-up") occur. With the upgrade of the accelerators, the luminosity and pile-up will more than double. The current pixel detector is crucial to charged particle tracking, but was not designed to perform effectively in such collision conditions and the physics program of CMS would suffer as a result. We propose to replace the current pixel tracker with a new high efficiency and low mass detector with four barrel layers and three forward/backward disks to provide four-hit pixel coverage out to pseudorapidities of ±2.5. This new detector will meet or exceed the original design specifications in these high luminosity environments. In this report, we provide details on the design, construction and installation of the upgraded pixel detector as well as estimates of its expected performance. Cover Design S. Cittolin AcknowledgmentsWe would like to thank the technical staff from the various institutions for the design, R&D and testing of the many components of this upgrade.We also wish to thank the LHCC for their oversight and crucial advice during the development of the the pixel upgrade project. The important feedback from following CMS internal reviewers greatly helped in the development of this technical design report: D. Contardo, S. Dasu, S.C. Eno, P. Giacomelli, G. Gomez Ceballos, E. Halkiadakis, C. Hill, M. Klute, S. Lowette, M. Mannelli, S. Nahn, I. Shipsey, D. Stuart, S. Tkaczyk and J. Varela.A special thanks goes to the CMS Secretariat, in particular Anastasia Dolya, for their tireless support during all stages of the project. We also acknowledge the warm support received from the CMS management team and computing project.Finally, we dedicate this technical design report for the upgrade of the pixel detector to the memory of our two colleagues and friends:

show abstract

Section: Samples and Event Selectionmentioning

confidence: 99%

CMS Technical Design Report for the Pixel Detector Upgrade

Dominguez¹

2012

View full text Add to dashboard Cite

show abstract

“…The jet reconstruction used energy deposits in the calorimeter. The jet triggers used anti-k t algorithm [15] with the radius parameter of R = 0.2 and 0.4 for Pb+Pb and pp collisions, respectively.In each data-taking period, the triggers were chosen to take as much advantage of the instantaneous luminosity as possible.…”

Section: Resultsmentioning

confidence: 99%

Measurement of the charged-hadron spectra and nuclear modification factor in lead–lead collisions with the ATLAS detector

Balek

2016

Nuclear and Particle Physics Proceedings

View full text Add to dashboard Cite

The ATLAS experiment at the Large Hadron Collider (LHC) measures charged hadron spectra obtained in 2010 and 2011 lead-lead LHC data taking periods with total integrated statistics of 0.15 nb −1 . The results are compared to the pp spectra of charged hadrons at the same centre-of-mass energy based on the data sample with integrated luminosity of 4.2 pb −1 obtained by the ATLAS experiment in 2011 and 2013. This allows a detailed comparison of the two collision systems in a wide transverse momentum (0.5 < pT < 150 GeV) and pseudorapidity (|η| < 2) ranges in different centrality intervals of Pb+Pb collision. The nuclear modification factor RAA is presented in detail as a function of centrality, pT and η. It shows a distinct pT-dependence with a pronounced minimum at about 7 GeV. Above 60 GeV, it is consistent with a flat, centrality-dependent, value within the uncertainties. The value is 0.55 ± 0.01(stat.) ± 0.04(syst.) in the most central collisions. The RAA is observed to be consistent with flat |η| dependence over the whole transverse momentum range in all centrality classes.

show abstract

“…For each event, reconstruct jets with the anti-k T algorithm [40] provided by the FastJet package [41] with radius R and within pseudo-rapidity |η jet | < η max ; 2. Within each jet, find subjets by reclustering the jet components with a smaller radius parameter R sj < R. Retain the two hardest (highest-p T ) subjets.…”

Section: Observable Definition and Setupmentioning

confidence: 99%

Novel subjet observables for jet quenching in heavy-ion collisions

et al. 2018

View full text Add to dashboard Cite

Using a novel observable that relies on the momentum difference of the two most energetic subjets within a jet ΔS 12 we study the internal structure of highenergy jets simulated by several Monte Carlo event generators that implement the partonic energy-loss in a dense partonic medium. Based on inclusive jet and dijet production we demonstrate that ΔS 12 is an effective tool to discriminate between different models of jet modifications over a broad kinematic range. The new quantity, while preserving the collinear and infrared safety of modern jet algorithms, it is experimentally attractive because of its inherent resilience against backgrounds of heavy-ion collisions.

show abstract

The anti-k_tjet clustering algorithm

Cited by 5,819 publications

References 24 publications

CMS Technical Design Report for the Pixel Detector Upgrade

CMS Technical Design Report for the Pixel Detector Upgrade

Measurement of the charged-hadron spectra and nuclear modification factor in lead–lead collisions with the ATLAS detector

Novel subjet observables for jet quenching in heavy-ion collisions

Contact Info

Product

Resources

About