Nonperturbative and spin effects in the central exclusive production of the tensor χc(2+) meson
Summary, in English
We discuss central exclusive production (CEP) of the tensor χc(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 χc(0+), χc(1+) and χc(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 +,2+) to the J/Ψ+γ channel to be comparable or larger than that of the χc(0+) one. This is partially due to a significant contribution from lower polarization states λ=0 for χc(1+) and λ=0, ±1 for χc(2+) meson. Corresponding theoretical uncertainties are discussed.
- Department of Astronomy and Theoretical Physics
Physical Review D (Particles, Fields, Gravitation and Cosmology)
American Physical Society
- ISSN: 1550-7998