Jet Broadening in the Opacity and Twist Expansions

Abstract

We compute the in-medium jet broadening $⟨p_{\perp }^2⟩$ to leading order in energy in the opacity expansion. At leading order in ${\alpha }_s$ the elastic energy loss gives a jet broadening that grows with $\ln E$. The next-to-leading order in ${\alpha }_s$ result is a jet narrowing, due to destructive LPM interference effects, that grows with ${\ln }^{2}E$. We find that in the opacity expansion the jet broadening asymptotics are -- unlike for the mean energy loss -- extremely sensitive to the correct treatment of the finite kinematics of the problem; integrating over all emitted gluon transverse momenta leads to a prediction of jet broadening rather than narrowing. We compare the asymptotics from the opacity expansion to a recent twist-4 derivation of $⟨p_{\perp }^2⟩$ and find a qualitative disagreement: the twist-4 derivation predicts a jet broadening rather than a narrowing. Comparison with current jet measurements cannot distinguish between the broadening or narrowing predictions. We comment on the origin of the difference between the opacity expansion and twist-4 results.

23 pages, 17 figures. v2 is consistent with the published version

References in corpus (16)

• Energy loss of a heavy quark moving through N=4 supersymmetric Yang-Mills plasma
• Drag force in AdS/CFT
• Calculating the Jet Quenching Parameter from AdS/CFT
• Heavy Quark Diffusion in Strongly Coupled $\mathbb{N}=4$ Yang Mills
• The theory and phenomenology of perturbative QCD based jet quenching
• A theory of jet shapes and cross sections: from hadrons to nuclei
• Determining the jet transport coefficient $\hat{q}$ from inclusive hadron suppression measurements using Bayesian parameter estimation
• Multistage Monte-Carlo simulation of jet modification in a static medium
• Jet quenching phenomenology from soft-collinear effective theory with Glauber gluons
• The non-linear evolution of jet quenching
• Radiative corrections to the jet quenching parameter in dilute and dense media
• Failure of the collinear expansion in calculation of the induced gluon emission
• Final State Gluon Emission in Deep-Inelastic Scattering at Next-to-Leading Twist
• Probing the Frontiers of QCD
• Global analysis of nuclear parton distribution functions at leading and next-to-leading order perturbative QCD
• Transverse momentum broadening at NLO and QCD evolution of $\hat{q}$

Cited by in corpus (1)

• Machine learning-based jet and event classification at the Electron-Ion Collider with applications to hadron structure and spin physics