Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions.

This report reviews the study of open heavy-flavour and quarkonium production in high-energy hadronic collisions, as tools to investigate fundamental aspects of Quantum Chromodynamics, from the proton and nucleus structure at high energy to deconfinement and the properties of the Quark-Gluon Plasma. Emphasis is given to the lessons learnt from LHC Run 1 results, which are reviewed in a global picture with the results from SPS and RHIC at lower energies, as well as to the questions to be addressed in the future. The report covers heavy flavour and quarkonium production in proton-proton, proton-nucleus and nucleus-nucleus collisions. This includes discussion of the effects of hot and cold strongly interacting matter, quarkonium photoproduction in nucleus-nucleus collisions and perspectives on the study of heavy flavour and quarkonium with upgrades of existing experiments and new experiments. The report results from the activity of the SaporeGravis network of the I3 Hadron Physics programme of the European Union 7[Formula: see text] Framework Programme.

Upsilon production at Fermilab Tevatron and LHC energies.

We update the theoretical predictions for direct Upsilon(nS) hadroproduction in the framework of nonrelativistic QCD. We show that the next-to-leading order corrections in alpha(S) to the color-singlet transition significantly raise the differential cross section at high p(T) and substantially affect the polarization of the Upsilon. Motivated by the remaining gap between the next-to-leading order yield and the cross-section measurements at the Fermilab Tevatron, we evaluate the leading part of the alpha(S)(5) contributions, namely, those coming from Upsilon(nS) associated with three light partons. The differential color-singlet cross section at alpha(S)(5) is in substantial agreement with the data, so that there is no evidence for the need of color-octet contributions. Furthermore, we find that the polarization of the Upsilon(nS) is longitudinal. We also present our predictions for Upsilon(nS) production at the LHC.

Possible solution of the J/psi production puzzle.

We argue that the s-channel cut contribution to J/psi hadroproduction can be significantly larger than the usual cut contribution of the color-singlet mechanism, which is known to underestimate the experimental measurements. A scenario accounting for intermediate cc[over ] interactions is proposed that reproduces the data at low and midrange transverse momenta P_(T) from the Fermilab Tevatron and BNL Relativistic Heavy Ion Collider. The J/psi produced in this manner are polarized predominantly longitudinally.