Next-to-leading-order tests of nonrelativistic-QCD factorization with J/ψ yield and polarization

Autor(en)
Mathias Butenschoen, Bernd A. Kniehl
Abstrakt

We report on recent progress in testing the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) at next-to-leading order (NLO) for J/? yield and polarization. We demonstrate that it is possible to unambiguously determine the leading color-octet long-distance matrix elements (LDMEs) in compliance with the velocity scaling rules through a global fit to experimental data of unpolarized J/? production in pp, pp, ep, ??, and e+e- collisions. Three data sets not included in the fit, from hadroproduction and from photoproduction in the fixed-target and colliding-beam modes, are nicely reproduced. The polarization observables measured in different frames at DESY HERA and CERN LHC reasonably agree with NLO NRQCD predictions obtained using the LDMEs extracted from the global fit, while measurements at the FNAL Tevatron exhibit severe disagreement. We demonstrate that alternative LDME sets recently obtained, with different philosophies, in two other NLO NRQCD analyses of J/? yield and polarization also fail to reconcile the Tevatron polarization data with the other available world data.

Organisation(en)
Teilchenphysik
Externe Organisation(en)
Universität Hamburg
Journal
Proceedings of Science (PoS)
Band
174
Anzahl der Seiten
12
DOI
https://doi.org/10.22323/1.174.0278
Publikationsdatum
2013
ÖFOS 2012
103034 Teilchenphysik
ASJC Scopus Sachgebiete
General
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/nexttoleadingorder-tests-of-nonrelativisticqcd-factorization-with-j-yield-and-polarization(aa0f3296-d9a2-499d-981d-94acb1b9ba5f).html