Low Q^2 boundary conditions for the Altarelli-Parisi equations dictated by quantum statistical mechanics.
by
Franco Buccella(Universita' Federico II, Napoli)
→
Europe/Rome
Sala Lauree (Dip. di Fisica - Edificio G. Marconi)
Sala Lauree
Dip. di Fisica - Edificio G. Marconi
Description
The phenomenological evidence for the role of quantum statistical mechanics for parton distributions has encouraged to write Fermi-Dirac expressions for the fermions and a Planck form for the gluons. The QCD equilibrium conditions for the elementary processes involved in DGLAP evolution equations allow to disentangle the contributions of the valence partons and of their antiparticles and give successful redictions for the isospin and spin asymmetries of the sea.The resulting parametrization has a better predictive power in the regions, where the experimental knowledge is scarce, than the standardpolynomial ones.