%0 Journal Article
%A Butenschoen, Mathias
%A He, Zhiguo
%A Kniehl, Bernd A.
%T η<sub>c</sub> production at the LHC challenges nonrelativistic-QCD factorization
%J Physical review letters
%V 114
%N 9
%@ 1079-7114
%C College Park, Md.
%I APS
%M PUBDB-2015-02008
%M DESY-14-219
%M arXiv:1411.5287
%P 092004
%D 2015
%X We analyze the first measurement of η<sub>c</sub> production, performed by the LHCb Collaboration, in the nonrelativistic QCD (NRQCD) factorization framework at next-to-leading order (NLO) in the strong-coupling constant α<sub>s</sub> and the relative velocity v of the bound quarks including the feeddown from h<sub>c</sub> mesons. Converting the long-distance matrix elements extracted by various groups from J/ψ yield and polarization data to the η<sub>c</sub> case using heavy-quark spin symmetry, we find that the resulting NLO NRQCD predictions greatly overshoot the LHCb data, while the color-singlet model provides an excellent description.
%K quantum chromodynamics: nonrelativistic (INSPIRE)
%K eta/c(2980) (INSPIRE)
%K heavy quark: spin (INSPIRE)
%K spin: symmetry (INSPIRE)
%K strong interaction: coupling constant (INSPIRE)
%K higher-order: 1 (INSPIRE)
%K factorization (INSPIRE)
%K LHC-B (INSPIRE)
%K color: singlet (INSPIRE)
%K strong coupling (INSPIRE)
%K CERN LHC Coll (INSPIRE)
%K polarization (INSPIRE)
%K velocity (INSPIRE)
%K quark (INSPIRE)
%K meson (INSPIRE)
%F PUB:(DE-HGF)29 ; PUB:(DE-HGF)16
%9 ReportJournal Article
%U <Go to ISI:>//WOS:000351288800002
%$ pmid:25793805
%R 10.1103/PhysRevLett.114.092004
%U https://bib-pubdb1.desy.de/record/209177