Speaker
Hannu Paukkunen
(University of Jyväskylä)
Description
The recent LHC and Tevatron data for inclusive high-$p_T$ charged hadron production in p+p(${\rm \bar{p}}$) collisions show a discrepancy in comparison to the NLO perturbative QCD predictions with modern fragmentation functions (FFs). We have quantified this observation by a systematic comparison between the calculations with different FF sets and data for several collision energies [1]. We show that especially the predictions with the most recent FFs clearly overshoot the high-$p_T$, high-$\sqrt{s}$ data even when the scale variations, and uncertainties in the PDFs and FFs are accounted for. We conclude that this behavior is due to the too hard gluon-to-hadron FFs, which calls for a complete re-analysis of the FFs using the high-$\sqrt{s}$ data at $p_T > 10\,\rm{GeV}$ where the theoretical uncertainties are only modest. We discuss also to what extent these discrepancies affect the interpretation of the LHC p+Pb collision data.
[1] D. d'Enterria, K.J. Eskola, I. Helenius and H. Paukkunen, *Confronting current NLO parton fragmentation functions with inclusive charged-particle spectra at hadron colliders*, arXiv:1311.1415 [hep-ph], submitted to Nucl. Phys. B.
Primary author
Mr
Ilkka Helenius
(University of Jyväskylä)
Co-authors
David d'Enterria
(CERN)
Hannu Paukkunen
(University of Jyväskylä)
Kari J. Eskola
(University of Jyvaskyla)
