Parton fragmentation functions

Selected recent HERMES results on parton distribution and fragmentation functions

The HERMES experiment has studied for more than a decade deep-inelastic scattering of electrons/positrons from longitudinally and transversely polarised and also unpolarised atomic gas targets internal to the electron storage ring of HERA. The collected semi-inclusive data allowed to extract informations about various quark distribution and fragmentation functions. Examples presented in this co...

Old and New Parton Distribution and Fragmentation Functions * )

A short review of problems with parton distribution functions in nucleons, non-polarized and polarized, is given. The main part is devoted to the transversity distribution its possible measurement and its first experimental probe via spin asymmetry in semi-inclusive DIS. It is argued that the proton transversity distribution could be successfully measured in future DIS experiments with longitud...

Evolution of Parton Fragmentation Functions at Finite Temperature

Parton production in hard processes is normally followed by final-state radiation and subsequent hadronization, giving rise to collimated jets of hadrons as observed in experiments. The hadron distributions inside a jet known as jet fragmentation functions can be defined as the vacuum expectation values of the parton fields and the hadronic interpolating fields [1]. Though these fragmentation f...

Parton Propagation and Fragmentation in QCD Matter

Alberto Accardi(1), François Arleo(2), William K. Brooks(3), David D’Enterria(4), and ValeriaMuccifora(5)(∗) (1) Hampton University, Hampton, VA, 23668, USA, and Jefferson Lab, Newport News, VA 23606, USA (2) LAPTH(∗∗), Université de Savoie, CNRS, BP 110, 74941 Annecy-le-Vieux cedex, France (3) Departamento de Fı́sica y Centro de Estudios Subatómicos, Universidad Técnica Federico Santa Marı́a, Ca...

Parton Distribution Functions