Related papers: Theoretical aspects of transversity observables
We predict the features of the Collins function, which describes the fragmentation of a transversely polarized quark into an unpolarized hadron, by modeling the fragmentation process at a low energy scale. We use the chiral invariant…
Predictions are made for single spin azimuthal asymmetries due to the Collins effect in pion production from semi-inclusive deeply inelastic scattering off transversely and longitudinally polarized targets for the HERMES and COMPASS…
In semi-inclusive deep inelastic scattering of polarized leptons on a transversely polarized target eight target transverse spin-dependent azimuthal modulations are allowed. In the QCD parton model half of these asymmetries can be…
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…
Transversity observables, such as the T-odd single-spin asymmetry measured in deep inelastic lepton scattering on polarized protons, and the distributions which are measured in deeply virtual Compton scattering provide important constraints…
The electron structure functions are studied in polarized $e^+e^-$ scattering. The formulae for longitudinally and transversely polarized electrons are presented. The smallnes of the electron mass leads to negligible cross-sections and…
The physics of hadron single transverse spin asymmetries is discussed. Possible measurements of both the quark and gluon Sivers functions are proposed.
Using the formalism of two-hadron fragmentation functions, we discuss single-spin asymmetries occurring in the production of two hadrons in the current region of deep inelastic scattering, with a particular emphasis on transversity…
We consider the Sivers, Collins and transversity functions as extracted from SIDIS and e+e- experimental data and investigate to what extent they might explain the large Single Spin Asymmetries (SSA) observed in proton-proton inclusive…
The Collins and Sivers asymmetries for charged hadrons produced in deeply inelastic scattering on transversely polarised protons have been extracted from the data collected in 2007 with the CERN SPS muon beam tuned at 160 GeV/c. At large…
The production of vector mesons in SIDIS is a particularly interesting channel to study the polarized fragmentation and related phenomena. Preliminary COMPASS results for the first measurement of inclusive $\rho^0$ Collins and Sivers…
In the TMD approach, the average transverse momentum of the unpolarised TMD PDFs and FFs is crucial not only to reproduce unpolarised cross sections and hadron multiplicities, but also for the understanding of azimuthal and spin…
One of the important objectives of the COMPASS experiment (SPS, CERN) \cite{Abbon:2007pq} is the exploration of the transverse spin structure of the nucleon via spin dependent azimuthal asymmetries in single-hadron production in deep…
By measuring transverse single spin asymmetries one has access to the transversity distribution function $\Delta_T q(x)$ and the transverse momentum dependent Sivers function $q_0^T(x,\vec{k}_T)$. New measurements from identified hadrons…
A collection of results is presented relevant for the analysis of azimuthal asymmetries in inclusive two-hadron production at BELLE. The aim of this overview is to provide theoretical ingredients necessary to extract the Collins effect…
We compute the contribution from the twist-3 fragmentation function for light hadron production in collisions between transversely and longitudinally polarized protons, i.e., $p^\uparrow \vec{p} \to h\,X$, which can cause a double-spin…
We review the present understanding of the nucleon transversity distribution and Collins fragmentation function, based on Ref.\cite{Efremov:2006qm}, and discuss how Drell-Yan experiments will improve it.
The Drell-Yan $K$-factors for transversely polarised hadrons are examined. Since transverse spin is peculiar in having no DIS reference point, the effects of higher-order corrections on DY asymmetries are examined via a DIS definition for…
The probabilistic model of parton distributions, previously developed by one of the authors, is generalized to include the transversity distribution. When interference effects are attributed to quark level only, the intrinsic quark motion…
We present the first extraction of the transversity distribution based on the global analysis of pion-pair production in deep-inelastic scattering and in proton-proton collisions with one transversely polarized proton. The extraction relies…