Production of f2 (1270) meson in pp collisions at the LHC via gluon-gluon fusion in the kt-factorization approach

We calculate inclusive cross section for f(2) (1270) tensor meson production via color singlet gluongluon fusion in the k(t)-factorization approach with unintegrated gluon distribution functions (UGDFs). The process may be potentially interesting in the context of searches for saturation effects. The energy-momentum tensor, equivalent to helicity-2 coupling, and helicity-0 coupling are used for the g*g* -> 1 f(2) (1270) vertex. Two somewhat different parametrizations of helicity-2 and helicity-0 tensorial structure from the literature are used in our calculations. Some parameters are extracted from gamma gamma -> f(2) (1270) -> pi pi reactions. Different modern UGDFs from the literature are used. The results strongly depend on the parametrization of the g*g* -> f(2) (1270) form factor. Our results for transverse momentum distributions of 1 2 are compared to preliminary ALICE data. We can obtain agreement with the data only at larger f(2) (1270) transverse momenta only for some parametrizations of the g*g* -> f(2) (1270) form factor. No obvious sign of the onset of saturation is possible. At low transverse momenta one needs to include also the pi pi final-state rescattering. The agreement with the ALICE data can be obtained by adjusting probability of formation and survival of f(2) (1270) in a harsh quark-gluon and multipion environment. The pomeron-pomeron fusion mechanism is discussed in addition and results are quantified. (C) 2020 The Author(s). Published by Elsevier B.V.