Intrinsic transverse momentum in hard processes
نویسنده
چکیده
In this contribution I discuss transverse momentum dependent quark distributions and their operator structure. Some of the experimental signatures in particular in Drell-Yan scattering are given.
منابع مشابه
hep-ph/9802378(ORNL-CTP-9802) Effects of Parton Intrinsic Transverse Momentum on Photon Production in Hard-Scattering Processes
We calculate the photon production cross section arising from the hard scattering of partons in nuclear collisions by taking into account the intrinsic parton transverse momentum distribution and the next-to-leading-order contributions. As first pointed out by Owens, the inclusion of the intrinsic transverse momentum distribution of partons leads to an enhancement of photon production cross sec...
متن کاملTransverse momentum of partons: from low to high pT
Transverse-momentum spectra in hard processes are typically described either in terms of intrinsic transverse momentum of 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 issue...
متن کاملTransverse polarization distribution and fragmentation functions
We discuss transverse polarization distribution and fragmentation functions, in particular, T-odd functions with transverse momentum dependence, which might be relevant for the description of single transverse spin asymmetries. The role of intrinsic transverse momentum in the expansion in inverse powers of the hard scale is elaborated upon. The sin single spin asymmetry in the process e p! e′ +...
متن کاملar X iv : h ep - p h / 99 05 56 2 v 1 3 1 M ay 1 99 9 Intrinsic k ⊥ in the pomeron
In a consistent QCD approach to diffractive DIS gluons in the pomeron have soft zg distribution and very broad intrinsic k⊥ distribution. The latter has not yet been incorporated into diffractive Monte-Carlo generators (RAPGAP,....). I argue that the so-introduced bias in the diffractive jet analysis may be the reason why H1 Collaboration finds the very large and hard gluon content of the pomer...
متن کاملTransversity of Quarks and Nucleons in Sidis and Drell Yan
One of the persistent challenges confronting the QCD parton model is the explanation of the significant azimuthal and single spin asymmetries that emerge in inclusive and semi-inclusive processes . Going beyond the collinear approximation in PQCD recent progress has been achieved in characterizing these asymmetries in terms of absorptive scattering . Such asymmetries involve time-reversal-odd (...
متن کامل