Eur. Phys. J. C (2016) 76: 53
https://doi.org/10.1140/epjc/s10052-016-3892-4

Regular Article - Theoretical Physics

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

¹ Theoretical High Energy Physics, IMAPP, Faculty of Science, Radboud University Nijmegen, Mailbox 79, P.O. Box 9010, 6500 GL, Nijmegen, The Netherlands
² Institute of Physics, University of Amsterdam, Amsterdam, The Netherlands
³ Institute for Theoretical Physics, WWU Münster, 48149, Münster, Germany
⁴ Institute for Theoretical Particle Physics and Cosmology, RWTH Aachen University, 52056, Aachen, Germany
⁵ ITFA, University of Amsterdam, Science Park 904, 1018 XE, Amsterdam, The Netherlands
⁶ ITF, Utrecht University, Leuvenlaan 4, 3584 CE, Utrecht, The Netherlands
⁷ Nikhef Theory Group, Science Park 105, 1098 XG, Amsterdam, The Netherlands
⁸ Department of Physics, University at Buffalo, The State University of New York, Buffalo, NY, 14260-1500, USA
⁹ Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford, OX1 3NP, UK

^* e-mail: anna.kulesza@uni-muenster.de

Received: 8 October 2015
Accepted: 4 January 2016
Published online: 28 January 2016

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 NLO+NLL 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.