Related papers: Transversity Distribution and Polarized Fragmentat…
Recently HERMES has observed an azimuthal asymmetry in electro-production of neutral pions in semi-inclusive deep-inelastic scattering of unpolarized positrons off longitudinally polarized protons. This asymmetry (like those observed in the…
The transversity distribution for $u$ and $d$ quarks is usually extracted from data on spin asymmetries in Semi Inclusive Deep Inelastic Scattering (SIDIS): however, due to its chiral odd nature, it has to be coupled to another chiral odd…
HERMES has measured azimuthal single-spin asymmetries of charged pions produced in deep-inelastic scattering of positrons on a transversely polarised hydrogen target. The presented azimuthal moments provide access to two yet unknown quark…
We present the principles of the measurement of the quark transversity distributions in semi-inclusive deep inelastic electron scattering, which form the basis of HELP and one of the ELFE proposals. A string model for Collins-type asymmetry…
We have updated our extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. The most recent COMPASS data…
I present some results about transverse momentum dependent distribution and fragmentation functions. Firstly I illustrate a simple model, with predictive power about the energy behavior, for T-odd, chiral odd functions. Moreover I propose a…
The transversity distribution can be measured at leading-twist in single-particle inclusive DIS, where it appears in connection with chiral-odd fragmentation functions. Among these functions, we focus on the time-reversal odd ones. They…
We present preliminary results for an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data…
The azimuthal spin asymmetries for pion production in semi-inclusive deep inelastic scattering of unpolarized charged lepton beams on longitudinally polarized nucleon targets, are reanalyzed by taking into account an important sign…
We present a model for dihadron fragmentation functions, describing the fragmentation of a quark into two unpolarized hadrons. We tune the parameters of our model to the output of the PYTHIA event generator for two-hadron semi-inclusive…
We review the present state of knowledge regarding the transverse polarisation (or transversity) distributions of quarks. After some generalities on transverse polarisation, we formally define the transversity distributions within the…
We present calculation on the azimuthal spin asymmetries for pion pair production in semi-inclusive deep inelastic scattering (SIDIS) process at both HERMES and COMPASS kinematics, with transversely polarized proton, deuteron and neutron…
We discuss in detail the option to access the transversity distribution function $h_1(x)$ by utilizing the analyzing power of interference fragmentation functions in two-pion production inside the same current jet. The transverse…
Generalized parton distributions describe the distribution of partons in the transverse plane. For transversely polarized quarks and/or nucleons, these impact parameter dependent parton distributions are not axially symmetric. These…
Single target-spin asymmetries in semi-inclusive two-pion production were measured for the first time by the HERMES experiment, using a longitudinally polarized deuterium target. These asymmetries relate to the unknown transversity…
We study the polarization of hyperon in different processes in singly polarized $pp$ collisions, in particular its relation to the polarized parton distributions. We show that by measuring hyperon polarization in particularly chosen…
We present the first extraction of the transversity distribution in the framework of collinear factorization based on the global analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets and in…
We present an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data for proton and deuteron…
Two related issues are discussed, which might be easily explored by present and future COMPASS experiments. The first one deals with the new world of transversity, the fundamental polarized parton distribution so far totally unknown. The…
Single-spin asymmetries for semi-inclusive electroproduction of charged pions in deep-inelastic scattering of positrons are measured for the first time with transverse target polarization. The asymmetry depends on the azimuthal angles of…