Probing nuclear dynamics in jet production with a global event shape

TL;DR

This paper develops a theoretical framework using 1-jettiness to analyze jet production in electron-nucleus collisions, enhancing sensitivity to nuclear medium effects and soft radiation patterns, with potential applications at future colliders.

Contribution

It introduces a factorization formalism for 1-jettiness in electron-nucleus collisions, enabling precise resummation and probing of nuclear PDFs and medium effects.

Findings

Resummation at NNLL accuracy for various nuclear targets.

Enhanced sensitivity to soft radiation and nuclear medium effects.

Theoretical control over jet shape analysis in the specified kinematic region.

Abstract

We study single jet production in electron-nucleus collisions e^- + N_A -> J + X, using the 1-jettiness (\tau_1) global event shape. It inclusively quantifies the pattern of radiation in the final state, gives enhanced sensitivity to soft radiation at wide angles from the nuclear beam and final-state jet, and facilitates the resummation of large Sudakov logarithms associated with the veto on additional jets. Through their effect on the observed pattern of radiation, 1-jettiness can be a useful probe of nuclear PDFs and power corrections from dynamical effects in the nuclear medium. This formalism allows for the standard jet shape analysis while simultaneously providing sensitivity to soft radiation at wide angles from the jet. We use a factorization framework for cross-sections differential in $\tau_1$ and the transverse momentum (P_{J_T}) and rapidity (y) of the jet, in the region \tau_1<< P_{J_T}. The restriction $\tau_1 << P_{J_T}$ allows only soft radiation between the nuclear beam and jet directions, thereby acting as a veto on additional jets. This region is also insensitive to the details of the jet algorithm, allowing for better theoretical control over resummation, while providing enhanced sensitivity to nuclear medium effects. We give numerical results at leading twist, with resummation at the next-to-next-to-leading logarithmic (NNLL) level of accuracy, for a variety of nuclear targets. Such studies would be ideal for the EIC and the LHeC proposals for a future electron-ion collider, where a range of nuclear targets are planned.