Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

Next-to-leading order QCD predictions for top-quark pair production with up to three jets

Stefan Höche, Philipp Maierhoefer, Niccolo Moretti, Stefano Pozzorini, Frank Siegert

TL;DR

This work delivers the first next-to-leading order QCD predictions for top-quark pair production in association with up to three jets, using SHERPA and OpenLoops. It systematically compares two scale-setting approaches—the fixed-order HT/2 scale and the MINLO method—to address the multi-scale nature of ttbar+multijet processes. Across ttbar+0–3 jets at 13 TeV, fixed-order NLO and MINLO show remarkable agreement, with differences within typical factor-two scale uncertainties and missing higher-order effects estimated at roughly the 10% level. The results validate both approaches as robust tools for precision background predictions at the LHC and provide detailed differential distributions and cross sections for phenomenology and validation purposes.

Abstract

We present theoretical predictions for the production of top-quark pairs with up to three jets at the next-to leading order in perturbative QCD. The relevant calculations are performed with Sherpa and OpenLoops. To address the issue of scale choices and related uncertainties in the presence of multiple scales, we compare results obtained with the standard scale HT/2 at fixed order and the MINLO procedure. Analyzing various cross sections and distributions for tt+0,1,2,3 jets at the 13 TeV LHC we find a remarkable overall agreement between fixed-order and MINLO results. The differences are typically below the respective factor-two scale variations, suggesting that for all considered jet multiplicities, missing higher-order effects should not exceed the ten percent level.

Next-to-leading order QCD predictions for top-quark pair production with up to three jets

TL;DR

This work delivers the first next-to-leading order QCD predictions for top-quark pair production in association with up to three jets, using SHERPA and OpenLoops. It systematically compares two scale-setting approaches—the fixed-order HT/2 scale and the MINLO method—to address the multi-scale nature of ttbar+multijet processes. Across ttbar+0–3 jets at 13 TeV, fixed-order NLO and MINLO show remarkable agreement, with differences within typical factor-two scale uncertainties and missing higher-order effects estimated at roughly the 10% level. The results validate both approaches as robust tools for precision background predictions at the LHC and provide detailed differential distributions and cross sections for phenomenology and validation purposes.

Abstract

We present theoretical predictions for the production of top-quark pairs with up to three jets at the next-to leading order in perturbative QCD. The relevant calculations are performed with Sherpa and OpenLoops. To address the issue of scale choices and related uncertainties in the presence of multiple scales, we compare results obtained with the standard scale HT/2 at fixed order and the MINLO procedure. Analyzing various cross sections and distributions for tt+0,1,2,3 jets at the 13 TeV LHC we find a remarkable overall agreement between fixed-order and MINLO results. The differences are typically below the respective factor-two scale variations, suggesting that for all considered jet multiplicities, missing higher-order effects should not exceed the ten percent level.

Paper Structure

This paper contains 5 sections, 3 equations, 6 figures, 2 tables.

Table of Contents

  1. Introduction
  2. Details of the calculation
  3. MINLO method and implementation
  4. Predictions for the 13 TeV LHC
  5. Conclusions

Figures (6)

  • Figure 1: Inclusive $t\bar{t}+$multijet cross sections with a minimum number $N=0,1,2,3$ of jets at $p_{\mathrm{T},\mathrm{jet}}\ge$25 GeV. See the main text for details.
  • Figure 2: Ratios of $t\bar{t}+N$ jet over $t\bar{t}+(N-1)$ jet inclusive cross sections for $N=1,2,3$ and $p_{\mathrm{T},\mathrm{jet}}\ge$25 GeV.
  • Figure 3: Distribution in the top-quark $p_{\mathrm{T}}$ for $pp\to t\bar{t}+0,1,2,3$ jets with $p_{\mathrm{T},\mathrm{jet}}\ge 25$ GeV.
  • Figure 4: Distribution in the $p_{\mathrm{T}}$ of the $t\bar{t}$ system for $pp\to t\bar{t}+1,2,3$ jets with $p_{\mathrm{T},\mathrm{jet}}\ge 25$ GeV.
  • Figure 5: Distribution in the $p_{\mathrm{T}}$ of the $n$-th jet for $pp\to t\bar{t}+n$ jets with $p_{\mathrm{T},\mathrm{jet}}\ge 25$ GeV and $n=1,2,3$.
  • ...and 1 more figures