Studies of jet mass in dijet and W/Z + jet events

TL;DR

This paper investigates jet mass spectra in proton-proton collisions at 7 TeV, comparing data with QCD predictions and exploring the impact of jet grooming techniques on the agreement between data and models.

Contribution

It provides a detailed analysis of jet mass spectra using different grooming techniques and compares experimental data with theoretical predictions, enhancing understanding of jet substructure.

Findings

Jet grooming improves agreement between data and QCD models.

Groomed jets better distinguish merged jets from soft radiation.

Data and predictions agree within uncertainties.

Abstract

Invariant mass spectra for jets reconstructed using the anti-kt and Cambridge-Aachen algorithms are studied for different jet "grooming" techniques in data corresponding to an integrated luminosity of 5 inverse femtobarns, recorded with the CMS detector in proton-proton collisions at the LHC at a center-of-mass energy of 7 TeV. Leading-order QCD predictions for inclusive dijet and W/Z+jet production combined with parton-shower Monte Carlo models are found to agree overall with the data, and the agreement improves with the implementation of jet grooming methods used to distinguish merged jets of large transverse momentum from softer QCD gluon radiation.