Related papers: Spin physics with spin-0 hadrons
A global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e+e- --> h1 h2 X processes, from the BELLE Collaboration, is…
Exploiting the azimuthal angle dependence of the density matrices we construct observables that directly measure the spin of a heavy unstable particle. A novelty of the approach is that the analysis of the azimuthal angle dependence in a…
A review is presented of some aspects of semi-inclusive deeply inelastic scattering and transversity. In particular, the role of $k_T$-dependent and higher-twist (or multi-parton) distributions in generating single-spin asymmetries is…
The azimuthal single target-spin asymmetries for pi^{+} production in semi-inclusive deep inelastic scattering of leptons off longitudinally polarized protons are evaluated using two main approaches available in the literature. It is shown…
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…
Recent results in polarized DIS are reviewed. Particular emphasis is placed on new measurements of transverse and longitudinal asymmetries, on the tests of the spin sum rules and on the analysis of the spin structure function $g_1$ in…
We study the single-transverse spin asymmetry in semi-inclusive hadron production in deep inelastic scattering. We derive the leading contribution to the asymmetry at moderate transverse momentum $P_{h\perp}$ of the produced hadron in terms…
A comprehensive set of azimuthal single-spin and double-spin asymmetries in semi-inclusive leptoproduction of pions, charged kaons, protons, and antiprotons from transversely polarized protons is presented. These asymmetries include the…
Recent measurements, in particular those on $\Lambda$ polarization and spin alignment of vector mesons in $e^+e^-$ annihilation at LEP, and those on the azimuthal asymmetry at HERA, have attracted much attention on the spin effects in high…
Transverse spin physics is an important part of the scientific programme of the COMPASS experiment at CERN, which started taking data in 2002, scattering 160 GeV/c muon beam on a polarized $^6$LiD target. The analysis of the data taken with…
We give a brief overview on some of the latest results on the transversity function. We focus on some recent extractions from azimuthal asymmetries data measured in semi-inclusive deep-inelastic scattering processes, and on the impact of…
A model for dihadron fragmentation functions is briefly outlined, that describes the fragmentation of a quark in two unpolarized hadrons. The parameters are tuned to the output of the PYTHIA event generator for two-hadron semi-inclusive…
A multi-dimensional (x, y, z, P_{h\perp}) extraction of cos\phi_h and cos2\phi_h azimuthal asymmetries of unpolarized Semi-Inclusive Deep Inelastic Scattering at HERMES is discussed. The use of data taken with hydrogen and deuterium targets…
A summary is given of how spin enters in collinearly factorizing processes. Next, theoretical aspects of polarization in processes beyond collinear factorization are discussed in more detail, with special focus on recent developments…
A pedagogical presentation of single-spin asymmetries and transversity is offered. Detailed discussion is given of various aspects of single-spin asymmetries in lepton-nucleon and in hadron-hadron scattering and of the role of perturbative…
We report on the first extraction of interference fragmentation functions from the semi-inclusive production of two hadron pairs in back-to-back jets in e+e- annihilation. A nonzero asymmetry in the correlation of azimuthal orientations of…
In inclusive deep-inelastic lepton-hadron scattering multi-photon exchange between the leptonic and the hadronic part of the process causes single spin asymmetries. The asymmetries exist for a polarized target as well as a polarized…
We consider the sin(phi) single target-spin asymmetry in deep-inelastic pi^{+} inclusive electroproduction off a longitudinally polarized target. We show that at larger transverse momentum of the outgoing hadron the evaluated asymmetry…
We consider within a generalized QCD factorization approach, the high energy inclusive polarized process p p --> pion + X, including all intrinsic partonic motions. Several new spin and k_T-dependent soft functions appear and contribute to…
We study the twist-three fragmentation function contribution to the single transverse spin asymmetries in inclusive hadron production in pp collisions, pp->h+X. In particular, we evaluate the so-called derivative contribution which…