相关论文: $q \to \Lambda$ Fragmentation Function and Nucleon…
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…
The amplitude of diffractive $\rho$ (and open quark) leptoproduction on a polarized target is calculated in the leading log approximation of pQCD using the hadron-parton duality hypothesis. The spin-spin asymmetry is expressed in terms of…
The unpolarised transverse momentum dependent distribution and fragmentation functions are extracted from HERMES and COMPASS experimental measurements of SIDIS multiplicities for charged hadron production. The data are grouped into…
Predictions are made for azimuthal asymmetries in pion and kaon production from SIDIS off a longitudinally polarized deuterium target for HERMES kinematics, based on information on the 'Collins fragmentation function' from DELPHI data and…
We present a phenomenological study on the role of charm contribution and $SU(2)$ isospin symmetry in the extraction of the $\Lambda$ polarizing fragmentation functions from $e^+e^- \to \Lambda^\uparrow (\bar\Lambda^\uparrow) \,h + X$…
The internal spin structure of the Lambda is of special importance for the understanding of the spin structure of hadrons in general. The comparison between the nucleon and Lambda allows for a test of the relevant flavour-symmetry breaking…
Using the linear sigma model to describe quark--pion interactions, we compute polarization asymmetries in quark fragmentation. We show that the effects of transverse quark polarizations appear in the correlation between the two leading…
The interference fragmentation function translates the fragmentation of a quark with a transverse projection of the spin into an azimuthal asymmetry of two final-state hadrons. In e+e- annihilation the product of two interference…
While jet quenching in relativistic heavy-ion collisions has been extensively studied over decades, the polarization of quenched hadrons has rarely been discussed. It has recently been proposed that the correlations of dihadron polarization…
The difference between the $\Lambda$ and $\bar \Lambda$ longitudinal spin transfers in the semi-inclusive deep inelastic scattering process is intensively studied. The study is performed in the current fragmentation region, by considering…
We discuss the recent interpretation of quark-distribution functions in the plane transverse to the light-cone direction. Such a mapping is model independent and allows one to build up multidimensional pictures of the hadron and to develop…
The investigation of transverse spin and transverse momentum effects in deep inelastic scattering is one of the key physics programs of the COMPASS collaboration. Three channels have been analyzed at COMPASS to access the transversity…
All the leading-twist parton distribution functions are calculated in a spectator model of the nucleon, using scalar and axial-vector diquarks. Single gluon rescattering is used to generate T-odd distribution functions. Different choices…
We provide a comprehensive overview of transversely polarized $\Lambda$ production at the future Electron-Ion Collider (EIC). In particular, we study both spontaneous transverse $\Lambda$ polarization as well as the transverse spin transfer…
We present a systematic study of the proton spin structure in terms of measurable parton distributions. For a transversely-polarizedproton, we derive a polarization sum rule from the leading generalized parton distributions appearing in…
A brief overview of various problems related to the description of a polarized proton in quark models is presented. Structure functions are discussed both for longitudinal and transverse polarization. A recently introduced quantity,…
We present [1] the first simultaneous extraction of the transversity distribution and the Collins fragmentation function, obtained through a combined analysis of experimental data on azimuthal asymmetries in semi-inclusive deep inelastic…
The class of interference fragmentation functions, arising from interference among different hadron production channels, is reconsidered. Their symmetry properties with respect to chiral transformations allow building spin asymmetries where…
A hybrid model is presented for hadron polarization that is based on perturbative QCD subprocesses and the recombination of polarized quarks to form polarized hadrons. The model, originally applied to polarized $\Lambda$'s that were…
Several experiments at the electron-proton ($ep$) collider HERA have collected high precision data on the spectrum of leading-proton and leading-neutron carrying a large fraction of the proton's energy. In this paper, we have analyzed…