The role of transverse momenta and spins in QCD at high energies

by Piet Mulders

Monday 11 Feb 2013, 14:30 → 16:00 Europe/Rome

Aula Conversi (Dip. di Fisica - Edificio. G. Marconi)

The standard Parton Distribution Functions (PDFs) used to describe high-energy scattering processes encode probabilities for finding specific quarks and gluons (partons) carrying fractions x of the parents hadron’s momentum (soft collinear part). The interactions of the partons (hard part) is calculated using perturbation theory in the Standard Model. The transverse Momentum Dependent (TMD) distribution functions also take into account the transverse momentum of the partons. Is this dependence a useful addition? Can it be measured? Can the formalism be set up and used in the same successful way as collinear PDFs, which are related to expectation values of field operators using the Operator Product Expansion in QCD? The answer is yes, but … . After accounting for the complications, quark and gluon TMDs offer new insight into spin and orbital substructure of hadrons while they also provide new tools to explore physics beyond the Standard Model.

Slides 2013-TheorySeminar-Rome.pdf