15 research outputs found
Transverse momentum distributions in Semi-inclusive Deep Inelastic Scattering
Within a perturbative approach to Quantum Chromodynamics (QCD), we show how
to extend ordinary DGLAP longitudinal evolution equations to include the
radiative transverse momentum generated in the collinear branching regime.
Considering Semi-inclusive Deep Inelastic Scattering as a reference process, we
perform such a generalization both in the current and in the target
fragmentation region. These distributions are then used to predict
semi-inclusive Deep Inelastic Scattering cross-sections onto the whole phase
space of the detected hadron.Comment: 6 pages. Invited talk at "Symmetries and Spin", Prague, July 19-2
Asymmetries involving dihadron fragmentation functions: from DIS to e+e- annihilation
Using a model calculation of dihadron fragmentation functions, we fit the
spin asymmetry recently extracted by HERMES for the semi-inclusive pion pair
production in deep-inelastic scattering on a transversely polarized proton
target. By evolving the obtained dihadron fragmentation functions, we make
predictions for the correlation of the angular distributions of two pion pairs
produced in electron-positron annihilations at BELLE kinematics. Our study
shows that the combination of two-hadron inclusive deep-inelastic scattering
and electron-positron annihilation measurements can provide a valid alternative
to Collins effect for the extraction of the quark transversity distribution in
the nucleon.Comment: 11 pages, RevTeX style, 6 figures in eps forma
One particle and Drell-Yan pair associated production
We briefly discuss the collinear factorization formula for the associated
production of one particle and a Drell-Yan pair in hadronic collisions. We
outline possible applications of the results to three different research areas.Comment: Presented at the workshop "30 years of strong interactions", Spa,
Belgium, 6-8 April 201
An application of transverse-momentum-dependent evolution equations in QCD
The properties and behaviour of the solutions of the recently obtained
-dependent evolution equations are investigated. When used to reproduce
transverse momentum spectra of hadrons in Semi-Inclusive DIS, an encouraging
agreement with data is found. The present analysis also supports at the
phenomenological level the factorization properties of the Semi-Inclusive DIS
cross-sections in terms of -dependent distributions. Further improvements
and possible developments of the proposed evolution equations are envisaged.Comment: 6 pages, page format correcte
A New Fracture Function Approach to QCD Initial State Radiation
Ordinary fracture functions, describing hadrons production in the deep
inelastic scattering target fragmentation region, are generalized to account
for the production of hadrons in arbitrary number, thus offering a renewed
framework for dealing with QCD initial state radiation. We also propose a new
jet-like observable which measures beam remnants and low- scattering
fragments and derive its QCD evolution equations by using Jet Calculus.
Possible implications for semi-inclusive deep inelastic scattering and
hadron-hadron reactions are shortly discussed.Comment: 10 pages, 5 figures, revtex
Evolution Equations for Extended Dihadron Fragmentation Functions.
We consider dihadron fragmentation functions, describing the fragmentation of
a parton in two unpolarized hadrons, and in particular extended dihadron
fragmentation functions, explicitly dependent on the invariant mass, , of
the hadron pair. We first rederive the known results on -integrated
functions using Jet Calculus techniques, and then we present the evolution
equations for extended dihadron fragmentation functions. Our results are
relevant for the analysis of experimental measurements of
two-particle-inclusive processes at different energies.Comment: 9 pages, 1 figure in eps format; RevTeX4 styl