Nonperturbative and spin effects in the central exclusive production of the tensor chi c(2(+)) meson
2010 (English)In: Physical Review D - Particles, Fields, Gravitation and Cosmology, ISSN 1550-7998, Vol. 81, no 3, 034024- p.Article in journal (Refereed) Published
We discuss central exclusive production (CEP) of the tensor chi(c)(2(+)) meson in proton-(anti) proton collisions at Tevatron, RHIC, and LHC energies. The amplitude for the process is derived within the kt-factorization approach. Differential and total cross sections are calculated for several unintegrated gluon distribution functions (UGDFs). We compare exclusive production of all charmonium states chi(c)(0(+)), chi(c)(1(+)) and chi(c)(2(+)). Good description of the recent Tevatron data is achieved both with Martin-Ryskin phenomenological UGDF and UGDF based on unified BFKL-DGLAP approach. Unlike for Higgs production, the main contribution to the diffractive amplitude of heavy quarkonia comes from nonperturbative region of gluon transverse momenta Q(perpendicular to) < 1 GeV. At y approximate to 0, depending on UGDF we predict the contribution of chi(c)(1(+), 2(+)) to the J/psi + gamma channel to be comparable or larger than that of the chi(c)(0(+)) one. This is partially due to a significant contribution from lower polarization states lambda = 0 for chi(c)(1(+)) and lambda = 0, +/- 1 for chi(c)(2(+)) meson. Corresponding theoretical uncertainties are discussed.
Place, publisher, year, edition, pages
2010. Vol. 81, no 3, 034024- p.
IdentifiersURN: urn:nbn:se:uu:diva-137118DOI: 10.1103/PhysRevD.81.034024ISI: 000275069000045OAI: oai:DiVA.org:uu-137118DiVA: diva2:377875