Tensor meson production in proton-proton collisions from the color glass condensate

Abstract

We compute the inclusive cross-section of f 2 tensor mesons production in protonproton collisions at high-energy. We use an effective theory inspired from the tensor meson dominance hypothesis that couples gluons to f 2 mesons. We compute the differential cross-section in the k ⊥ -factorization and in the Color Glass Condensate formalism in the low density regime. We show that the two formalisms are equivalent for this specific observable. Finally, we study the phenomenology of f 2 mesons by comparing theoretical predictions of different parameterizations of the unintegrated gluon distribution function. We find that f 2 -meson production is another observable that can be used to put constraints on these distributions. I. INTRODUCTIONHigh energy hadronic collisions are complex phenomena that combine many-particles physics and Quantum Chromodynamics (QCD). Making predictions for the production of particles in these reactions involves the understanding of both hadron wave-function and processes of particle creation. Many advances have been made in the last decades in those fields through the application of perturbative QCD (pQCD) to the description of experimental data. The pQCD analysis relies generally on factorization schemes like Collinear Factorization and k ⊥ -factorization. Different procedures are implemented in these approaches to improve the perturbation expansion by resumming infrared divergences. Many observables are well-described by QCD factorizations. For example, k ⊥ -factorization was used successfully in proton-antiproton collisions for heavy-quarks production [1,2,3,4,5,6,7,8,9] while collinear factorization is one of the main computational tool for deep inelastic scattering and for a number of other applications [10,11]. The main difference between the two formalisms is their validity range.

Wilson-line and color charge density correlators and the production ofη'in the color glass condensate forppand<

“…Thus, by combining this analysis with experimental data, the η ′ production becomes another observable that can be utilized to constrain models of uPDF. A similar conclusion was reached in [31] where the f 2 -meson production was studied. Note however that the results of the cross section at small transverse momentum should be treated carefully.…”

“…Finally, from the theoretical point of view, we studied pp collisions to see if the cross section can be obtained as the low density limit of the pA cross section. There are now many known examples where this can be seen like gluon production [50,56,68], quark production [48,57] and tensor meson production [31]. We have shown that η ′ production also obeys this property and in that sense, it is a consistency check for the approach used for the pA case.…”

“…Using this kinematics, it is possible to compute the high-energy limit of the matrix element M. This can then be inserted in the expression of the cross section which is finally given by (see [12,13,31] for more details and similar calculations)…”

“…Contrary to pions, the data in high energy hadronic collisions for η ′ is scarce, so another approach is required to take care of hadronization effects and internal structure of the η ′ meson. In [31], an effective theory is used to estimate the tensor meson production in pp collisions. We use a similar approach in this article where the interaction between gluons and η ′ is described by an effective theory.…”

Inclusive production of $f_2(1270)$ tensor mesons at the LHC via gluon-gluon fusion in the $k_t$-factorization approach

“…The gluon-gluon fusion was already considered in the past [3]. Recently [4] we discussed this mechanism more carefully.…”