Related papers: Spin dependent fragmentation function at Belle
Predictions for the single transverse spin asymmetry A_N in semi-inclusive DIS processes are given; non negligible values of A_N may arise from spin effects in the fragmentation of a polarized quark into a final hadron with a transverse…
We present a global analysis of Sivers functions, transversity distribution functions, and Collins fragmentation functions within the transverse momentum dependent factorization. This analysis encompasses the latest data from semi-inclusive…
The NJL-jet model is extended to accommodate hadronization of a transversely polarized quark in order to explore the Collins effect within a multihadron emission framework. This is accomplished by calculating the polarized quark spin flip…
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…
We use a new set of Collins functions to update a previous prediction on the azimuthal asymmetries of pion productions in semi-inclusive deep inelastic scattering (SIDIS) process on a transversely polarized nucleon target. We find that the…
Within the LO QCD parton model of Semi Inclusive Deep Inelastic Scattering, $\ell N \to \ell h X$, with unintegrated quark distribution and fragmentation functions, we study the $\bfP_{hT}$ dependence of the double longitudinal-spin…
A new class of fragmentation functions, arising from the interference of different hadron production channels, is analyzed. Their symmetry properties with respect to naive time-reversal transformations allow for the exploration of…
Understanding the origin of transverse single-spin asymmetries is a long-standing challenge in strong interaction physics. Recent precise measurements of the azimuthal distribution of charged pions in jets from STAR have shed new light on…
The correlation between the longitudinal polarization of a fragmenting quark and the transverse momenta of the produced hadrons was predicted over two decades ago. Nevertheless, experimental searches in the electron-positron annihilation…
We study the transverse momentum dependent (TMD) evolution of the Collins azimuthal asymmetries in $e^+e^-$ annihilations and semi-inclusive hadron production in deep inelastic scattering (SIDIS) processes. All the relevant coefficients are…
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…
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…
We study single-spin asymmetries in semi-inclusive deep inelastic scattering with transversely polarized target. Based on the QCD factorization approach, we consider Sivers and Collins contributions to the asymmetries. We fit simple…
The paper calculates the helicity-dependent dihadron fragmentation function (DiFF), by extending the dihadron spectator model and examine the single longitudinal spin asymmetry $A^{\sin(2\phi_h)}_{UL}$ from dihadron in semi-inclusive…
Fragmentation functions represent a key ingredient to address the proton spin structure in semi-inclusive deep-inelastic scattering and proton-proton collisions. They can not be determined from perturbative Quantum Chromodynamics and have…
Within the most recent extension of the quark-jet hadronization framework, we explore the transverse-polarization-dependent dihadron fragmentation functions (DiFFs) $H_1^\sphericalangle$ and $H_1^\perp$ of a quark into $\pi^+\pi^-$ pairs.…
Azimuthal spin asymmetries, both for charged and neutral pion production in semi-inclusive deep inelastic scattering of unpolarized charged lepton beams on longitudinally and transversely polarized nucleon targets, are analyzed and…
The main aim of this paper is a new determination of transverse momentum dependence of unpolarized fragmentation function (TMD FFs) in single inclusive hadron production in electron-positron annihilation (SIA) process. Motivated by the need…
Recently it has been argued that the transverse momentum dependent twist-2 Sivers distribution function does not vanish in QCD. Therefore both, the Collins and Sivers effects, should be considered in order to explain the azimuthal single…
We discuss the properties of fragmentation functions arising from the interference of two leading hadrons produced inside the same jet in the current fragmentation region of a hard process. For the case of semi-inclusive Deep Inelastic…