NLO+NLL squark and gluino production cross-sections with threshold-improved parton distributions

TL;DR

This paper provides updated NLO+NLL cross-section predictions for squark and gluino pair production at the LHC, incorporating recent threshold-improved PDFs and analyzing their impact on theoretical uncertainties and central values.

Contribution

It introduces the use of threshold-improved NNPDF3.0 PDFs in NLO+NLL calculations, highlighting their effect on cross-section predictions and uncertainties.

Findings

Threshold-improved PDFs cause shifts within the total uncertainty band.

Central cross-section values are significantly modified by threshold resummation.

Updated cross-sections are publicly available for experimental analysis.

Abstract

We present updated predictions for the cross-sections for pair production of squarks and gluinos at the LHC Run II. First of all, we update the calculations based on NLO+NLL partonic cross-sections by using the NNPDF3.0NLO global analysis. This study includes a full characterization of theoretical uncertainties from higher orders, PDFs and the strong coupling. Then, we explore the implications for this calculation of the recent NNPDF3.0 PDFs with NLO+NLL threshold resummation. We find that the shift in the results induced by the threshold-improved PDFs is within the total theory uncertainty band of the calculation based on NLO PDFs. However, we also observe that the central values of the cross-sections are modified both in a qualitative and a quantitative way, illustrating the relevance and impact of using threshold-improved PDFs together with resummed partonic cross-sections. The updated NLO+NLL cross-sections based on NNPDF3.0NLO are publicly available in the NLL-fast format, and should be an important ingredient for the interpretation of the searches for supersymmetric particles at Run II.