出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：Transverse-momentumspectra in hard processes are typically described either in terms of intrinsic
transversemomentumof partons, or in terms of perturbative radiation. The relation between these
descriptions is discussed for the example of semi-inclusive deep inelastic scattering, with special
focus on the angular distribution of the observed hadron. This involves nontrivial theoretical
issues, such as the proper definition of transverse-momentumdependent parton distributions, and
has practical consequences for the description of pT spectra in phenomenology.
