Transverse momentum as a probe of QCD in the Deep Infrared

by Dr Andrea Simonelli

Tuesday 24 Feb 2026, 11:30 → 12:30 Europe/Rome

Aula Fubini (Nuovo Edificio)

Extracting information on the three-dimensional structure of
hadrons from transverse momentum data is challenging, as it requires
disentangling well-controlled perturbative contributions from genuinely
non-perturbative effects, which are inevitably influenced by
phenomenological assumptions. This subtle interplay often obscures the
interpretation of phenomenological analyses, even when they accurately
describe experimental data.
In this seminar, I present a systematic procedure to analytically
continue perturbative calculations into the deep infrared, below 1-2
GeV, highlighting two main sources of non-perturbative effects: the
low-energy behavior of the strong coupling and of the parton
distribution functions. This approach makes
transverse-momentum-dependent data a privileged tool to probe strong
interactions in a poorly understood regime, providing novel insights
into the strong coupling and PDFs where they are least constrained.