English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We discuss central exclusive production (CEP) of the tensor $\chi_c(2^{+})$meson in proton-(anti)proton collisions at Tevatron, RHIC and LHC energies. Theamplitude for the process is derived within the $k_t$-factorisation approach.Differential and total cross sections are calculated for several unintegratedgluon distributions (UGDFs). We compare exclusive production of all charmoniumstates $\chi_c(0^+),\,\chi_c(1^+)$ and $\chi_c(2^+)$. Equally good descriptionof the recent Tevatron data is achieved both with Martin-Ryskinphenomenological UGDF and UGDF based on unified BFKL-DGLAP approach. Unlike forHiggs production, the main contribution to the diffractive amplitude of heavyquarkonia comes from nonperturbative region of gluon transverse momenta$Q_{\perp}<1\,\GeV$. At $y \approx$ 0, depending on UGDF we predict thecontribution of $\chi_c(1^+,2^+)$ to the $J/\Psi + \gamma$ channel to becomparable or larger than that of the $\chi_c(0^+)$ one. This is partially dueto a significant contribution from lower polarization states $\lambda=0$ for$\chi_c(1^+)$ and $\lambda=0,\,\pm 1$ for $\chi_c(2^+)$ meson. Correspondingtheoretical uncertainties are discussed.

Nonperturbative and spin effects in the central exclusive production of tensor $\chi_c(2^+)$ meson