Eur. Phys. J. C (2018) 78: 621
https://doi.org/10.1140/epjc/s10052-018-6090-8

Regular Article - Theoretical Physics

Impact of low-x resummation on QCD analysis of HERA data

¹ Faculty of Physics, Semnan University, Semnan, 35131-19111, Iran
² Department of Physics and Astronomy, VU University, 1081 HV, Amsterdam, The Netherlands
³ NIKHEF Theory Group, Science Park 105, 1098 XG, Amsterdam, The Netherlands
⁴ Physikalisches Institut, Universität Heidelberg, Im Neuenheimer Feld 226, 69120, Heidelberg, Germany
⁵ CERN, 1211, Geneva 23, Switzerland
⁶ Particle Physics, Denys Wilkinson Bdg, Keble Road, University of Oxford, OX1 3RH, Oxford, UK
⁷ Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607, Hamburg, Germany
⁸ Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, 31-342, Cracow, Poland
⁹ T. Kosciuszko Cracow University of Technology, 30-067, Cracow, Poland
¹⁰ SMU Physics, Box 0175 , Dallas, TX, 75275-0175, USA
¹¹ Joint Institute for Nuclear Research (JINR), Joliot-Curie 6, 141980, Dubna, Moscow Region, Russia
¹² INFN, Sezione di Roma 1, Piazzale Aldo Moro 5, 00185, Rome, Italy

^* e-mail: valerio.bertone@cern.ch

Received: 13 February 2018
Accepted: 21 July 2018
Published online: 3 August 2018

Abstract

Fits to the final combined HERA deep-inelastic scattering cross-section data within the conventional DGLAP framework of QCD have shown some tension at low x and low . A resolution of this tension incorporating -resummation terms into the HERAPDF fits is investigated using the xFitter program. The kinematic region where this resummation is important is delineated. Such high-energy resummation not only gives a better description of the data, particularly of the longitudinal structure function , it also results in a gluon PDF which is steeply rising at low x for low scales, , contrary to the fixed-order NLO and NNLO gluon PDF.