Speaker
Description
Pion parton distribution functions have been achieving most interest among hadronic physicists in this years; nevertheless there are still few models that use a light-front wave function (LFWF) approach for the pion.
Our theoretical model is based on the pion-state decomposition in terms of different Fock state components. In particular, we focused on the lowest number of partons constituting the pion state: 2 partons (quark-antiquark), 3 partons (quark-antiquark-gluon) and 4 partons (quark-antiquark-gluon-gluon & quark-antiquark-sea). Since the pion states enter directly in the definitions of all the parton distribution functions, these last can be re-written as overlaps of LFWFs.
Our model permits to parameterize different types of parton distribution functions, for example the collinear parton distribution functions (PDFs), the transverse momentum dependent parton distribution functions (TMDs) and the pion form factor (FF). The flexibility of the model permits to perform separate fits, providing complementary information about the internal structure: one fit for the collinear part (PDFs) and another fit for the transverse-direction dependent parameters. The latter can be performed for the pion FFs or for the pion TMDs. The idea is to perform one of these two fits and to use the best-fit parameters to predict the trend of the other, and vice-versa, in order to provide a double corss check in the transverse direction.
