Study of J/Psi and Y production in association with leading hadron at RHIC and LHC energies

Abstract

We demonstrate that current experimental data on γ/Z 0 and heavy quarkonium production in pp collisions at RHIC and LHC energies can be described by the color dipole formalism. Three different phenomenological models based on saturation physics are used to estimate the DrellYan (DY) dilepton spectra in such processes. In order to further constrain QCD dynamics we suggest to measure the azimuthal correlation function C(∆φ ) between mid-rapidity DY pairs and central/forward pions. On the other hand, this is a key background for C-odd heavy quarkonia (e.g. J/ψ and ϒ) production at high p T 's which can be accompanied by a high-p T hadron from fragmentation of an additional gluon according to the Color-Singlet model (CSM). As a first step, we have estimated the transverse momentum distributions J/ψ and ϒ in the dipole CSM and found a reasonable agreement with data at various energies. Similarly to the DY case we suggest to study correlations between a high-p T jet and J/ψ or ϒ in the dilepton channel at mid-rapidities.