[Hybrid RBRC seminar] Accessing gluon TMDs through Quarkonium observables

by Luca Maxia

Thursday 2 May 2024, 12:30 → 13:30 US/Eastern

2-219 ( https://bnl.zoomgov.com/j/1619458475?pwd=Z1VDdXVXcWF1eUhsRDZObVJnME4rUT09)

Abstract:

Although protons have been studied in terms of their partonic constituents for more than half a century, the full picture is still obscure, especially if one includes polarization and transverse momentum effects. A key area of uncertainty is the gluon contribution, knowledge of which lags behind the quarks one. Thus, identifying observables that are sensitive to gluons is highly valuable. In particular, quarkonia can be considered as very important tools to probe gluon transverse momentum dependent (TMD) distributions at lower energies as compared, for instance, to Higgs production. Among them, the $J/\psi$ meson is one of the most studied, since it frequently decays into lepton pairs, making its detection easier with respect to other quarkonia. However, the formalism that properly describes quarkonium production is still under debate. 

 

Therefore, in this talk I will present a selected (hence incomplete) overview of recent works published in the 2020s. The first part prioritizes those studies that can help to shed light on the validity of the so-called color-octet mechanism, and consequently the applicability of the nonrelativistic QCD (NRQCD) approach. The second part explores observables measurable either at the Electron-Ion Collider or the LHC that are directly sensitive to gluon TMDs.