Gauge-boson production with multiple jets near threshold

TL;DR

This paper develops an effective theory framework to resum large Sudakov logarithms in gauge-boson plus jets production near threshold, improving predictions for Standard Model backgrounds in new physics searches.

Contribution

It introduces a novel resummation method for threshold logarithms in gauge-boson plus jets production using N-jettiness, with explicit NLL results for gamma plus two jets.

Findings

Resummation significantly alters the $m_{eff}$ distribution shape.

Explicit NLL results for $pp \to \gamma + 2$ jets are provided.

Framework improves theoretical control over jet veto logarithms.

Abstract

Signatures of new physics beyond the Standard Model are often characterized by large missing transverse energy ($\not E_T$) produced in association with multiple jets. The dominant Standard Model background to such processes comes from gauge-boson production in association with jets. A standard search strategy involves looking for an excess in the $m_{eff}$ distribution, where $m_{eff}= \not E_T +\sum_{J} p^T_J$ and $p^T_J$ denotes the transverse momentum of the $J$-th jet. The region of large $m_{eff}$ is dominated by jet production near threshold, giving rise to large Sudakov logarithms that can change the magnitude and shape of the $m_{eff}$ distribution. We present an effective theory framework for the resummation of such threshold logarithms. We perform an analysis for exclusive jet production using the N-jettiness global event shape, which allows theoretical control to also be maintained over large logarithms induced by vetoing additional jets. As a first step, we give explicit numerical results with next-to-leading-log (NLL) resummation for $pp \to \gamma + 2$ jets in the large $m_{eff}$ region.