Dissecting Soft Radiation with Factorization

Abstract

An essential part of high-energy hadronic collisions is the soft hadronic activity that underlies the primary hard interaction. It includes soft radiation from the primary hard partons, secondary multiple parton interactions (MPI), and factorization-violating effects. The invariant mass spectrum of the leading jet in $Z$+jet and $H$+jet events is directly sensitive to these effects, and we use a QCD factorization theorem to predict its dependence on the jet radius $R$, jet $p_T$, jet rapidity, and partonic process for both the perturbative and nonperturbative components of primary soft radiation. We prove that the nonperturbative contributions involve only odd powers of $R$, and the linear $R$ term is universal for quark and gluon jets. The hadronization model in PYTHIA8 agrees well with these properties. The perturbative soft initial state radiation (ISR) has a contribution that depends on the jet area in the same way as the underlying event, but this degeneracy is broken by dependence on the jet $p_T$. The size of this soft ISR contribution is proportional to the color state of the initial partons, yielding the same positive contribution for $gg\to Hg$ and $gq\to Zq$, but a negative interference contribution for $q\bar{q}\to Zg$. Hence, measuring these dependencies allows one to separate hadronization, soft ISR, and MPI contributions in the data.

11 pages, 11 figures, v2: PRL version, text rearranged

References in corpus (39)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• The anti-k_t jet clustering algorithm
• A Brief Introduction to PYTHIA 8.1
• FastJet user manual
• Herwig++ Physics and Manual
• Tuning Monte Carlo Generators: The Perugia Tunes
• General-purpose event generators for LHC physics
• N-Jettiness: An Inclusive Event Shape to Veto Jets
• Thrust at N^3LL with Power Corrections and a Precision Global Fit for alphas(mZ)
• Power corrections to event shapes and factorization
• Systematic event generator tuning for the LHC
• Colour reconnections in Herwig++
• Treating the b quark distribution function with reliable uncertainties
• Jet mass and substructure of inclusive jets in sqrt(s) = 7 TeV pp collisions with the ATLAS experiment
• Momentum Flow Correlations from Event Shapes: Factorized Soft Gluons and Soft-Collinear Effective Theory
• Non-perturbative QCD effects in jets at hadron colliders
• Measurement of the Underlying Event Activity at the LHC with sqrt(s)= 7 TeV and Comparison with sqrt(s) = 0.9 TeV
• Designing Gapped Soft Functions for Jet Production
• Measurement of underlying event characteristics using charged particles in pp collisions at $\sqrt{s}=900GeV$ and 7 TeV with the ATLAS detector
• Jets and Quantum Field Theory
• Constraining MPI models using sigma_effective and recent Tevatron and LHC Underlying Event data
• On the characterisation of the underlying event
• Studies of jet mass in dijet and W/Z + jet events
• Power Corrections to Event Shapes with Mass-Dependent Operators
• Jet Mass Spectra in Higgs + One Jet at NNLL
• The Soft Function for Exclusive N-Jet Production at Hadron Colliders
• On jet mass distributions in Z+jet and dijet processes at the LHC
• Energy flow in QCD and event shape functions
• The Underlying Event in Hard Interactions at the Tevatron pbarp Collider
• Resummed event-shape variables in DIS
• On the breaking of collinear factorization in QCD
• Glauber Gluons and Multiple Parton Interactions
• Using 1-Jettiness to Measure 2 Jets in DIS 3 Ways
• Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron
• Reparameterization Invariant Collinear Operators
• Measurement of the underlying event in the Drell-Yan process in proton-proton collisions at sqrt(s) = 7 TeV
• Resummation of Jet Mass at Hadron Colliders
• Measurements of underlying-event properties using neutral and charged particles in pp collisions at 900 GeV and 7 TeV with the ATLAS detector at the LHC

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