Extrapolating W-Associated Jet-Production Ratios at the LHC

TL;DR

This paper analyzes ratios of W+jets production at the LHC to predict higher jet multiplicities, providing a method to extrapolate cross sections and distributions for complex processes crucial for new physics searches.

Contribution

It introduces a novel extrapolation technique for W+jet production ratios to estimate high-multiplicity cross sections at NLO, validated against direct calculations.

Findings

Ratios of W+jets production can be used to predict higher jet multiplicity cross sections.

The extrapolation method accurately estimates W+6 jet production at NLO.

Predicted $H_T^{jets}$ distribution for W+6 jets at NLO.

Abstract

Electroweak vector-boson production, accompanied by multiple jets, is an important background to searches for physics beyond the Standard Model. A precise and quantitative understanding of this process is helpful in constraining deviations from known physics. We study four key ratios in $W + n$-jet production at the LHC. We compute the ratio of cross sections for $W + n$- to $W + (n-1)$-jet production as a function of the minimum jet transverse momentum. We also study the ratio differentially, as a function of the $W$-boson transverse momentum; as a function of the scalar sum of the jet transverse energy, $H_T^{\rm jets}$; and as a function of certain jet transverse momenta. We show how to use such ratios to extrapolate differential cross sections to $W+6$-jet production at next-to-leading order, and we cross-check the method against a direct calculation at leading order. We predict the differential distribution in $H_T^{\rm jets}$ for $W+6$ jets at next-to-leading order using such an extrapolation. We use the BlackHat software library together with SHERPA to perform the computations.