2015/10/08 by S. P. Baranov, A. V. Lipatov, N. P. Zotov · 3 citations
Mathematics · Physics and Astronomy · #Algorithm #Atlas (anatomy) #Factorization #Gluon #High-Energy Particle Collisions Research #Large Hadron Collider #Mathematics #Meson #Octet #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #hep-ph
paper · pdf · doi:10.1103/physrevd.93.094012
published as Phys. Rev. D 93, 094012 (2016) · 11 pages, 3 figures
arxiv created 2015/10/08 · openalex publication_date 2016/05/17 · arxiv updated 2016/05/25 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
In the framework of the kT-factorization approach, the production of prompt \ensuremathψ(2S) mesons in pp collisions at the LHC energies is studied. Our consideration is based on the off-shell amplitudes for hard partonic subprocesses g*g*\ensuremath→\ensuremathχcJ and nonrelativistic QCD formalism for bound states. The transverse-momentum-dependent (unintegrated) gluon densities in a proton were derived from the Ciafaloni-Catani-Fiorani-Marchesini evolution equation or, alternatively, were chosen in accordance with the Kimber-Martin-Ryskin prescription. Taking into account both color-singlet and color-octet contributions, we deduce the corresponding nonperturbative long-distance matrix elements from the fits to the latest ATLAS data on \ensuremathχc1 and \ensuremathχc2 transverse-momentum distributions at √(s)=7 TeV. We find that these distributions at small and moderate pT are formed mainly by the color-singlet components. We successfully described the data on the relative production rates \ensuremathσ(\ensuremathχc2)/\ensuremathσ(\ensuremathχc1) presented by the ATLAS, CMS, and LHCb Collaborations. We find that the fit points to unequal wave functions of \ensuremathχc1 and \ensuremathχc2 states.