相关论文: Semi-inclusive Pion Production and the d/u Ratio
We calculate azimuthal asymmetries and the Callan-Gross $R$-ratio for semi-exclusive pion production in deep inelastic scattering taking into account higher twist effects. Our results are qualitatively different from the QCD-improved parton…
Semi-inclusive electron scattering provides a powerful tool with which to study the spin and flavor distributions in the proton. Greater kinematic coverage at the proposed Electron-Polarized Ion Collider facility will enable the valence d/u…
A large set of cross sections for semi-inclusive electroproduction of charged pions ($\pi^\pm$) from both proton and deuteron targets was measured. The data are in the deep-inelastic scattering region with invariant mass squared $W^2$ > 4…
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…
The concept of parton fragmentation in QCD hard scattering phenomenology as well as NLO pQCD analysis of fragmentation functions are outlined. Hadroproduction of pions of a few GeV pT is discussed through the example of recent measurements…
We show that measurements of semi-inclusive $\pi^\pm$ asymmetries on $p$ and $n$ with polarized and unpolarized target and beams allow, without any knowledge of the polarized parton densities 1) to test independent fragmentation and SU(2)…
We discuss how to extract the polarized parton densities and fragmentation functions in a model independent way from SIDIS, and present results for D_{u,d,s}^{\pi^+}.
Recent analysis of proton and deuteron deep-inelastic scattering data have suggested that the extracted d/u quark distribution ratio at large x may be significantly larger than previously believed, if the data are corrected for nuclear…
At the energies of present and future electron accelerators designed to study the structure of hadrons, there is a regime where hard pion electroproduction proceeds by a perturbatively calculable process in QCD. The process is not the…
An explicit pionic component of the nucleon may be identified by measuring polarized $\Delta^{++}$ fragments produced in deep-inelastic scattering off polarized protons. The pion-exchange model predicts highly correlated polarizations of…
By combining recent HERMES data on semi-inclusive DIS $\pi^\pm$-production with the singlet fragmentation function $D_\Sigma^{\pi^+}$, which is well determined from $e^+e^-$ data, we are able to extract, for the first time, the flavoured…
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…
We present an extraction of the valence transversity parton distributions based on an analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets. Recently released data for proton and deuteron targets…
We explore quark-hadron duality in semi-inclusive pion electroproduction on proton and neutron targets. Using the spin-flavor symmetric quark model, we compute ratios of pi+ and pi- cross sections for both unpolarized and polarized…
We extend the analysis of two-hadron fragmentation functions to the subleading twist, discussing also the issue of color gauge invariance. Our results can be used anywhere two unpolarized hadrons are semi-inclusively produced in the same…
We suggest a method of determination of the pion structure function down to x \simeq 10^{-4} based on semi-exclusive deep inelastic scattering off protons. The idea is to exploit the nonperturbative \pi N$ and \pi\Delta Fock components of…
We explore further applications of the twist-two quark interference fragmentation functions introduced earlier. We show that semi-inclusive production of two pions in the current fragmentation region in deep inelastic scattering of a…
We investigate the properties of interference fragmentation functions arising from the emission of two leading hadrons inside the same jet for inclusive lepton-nucleon deep-inelastic scattering. Using an extended spectator model for the…
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…
We propose a new formula for extracting the polarized gluon distribution $\Delta g$ in the proton from the large--$p_T$ light hadron pair production in deep inelastic semi-inclusive reactions. Though the process dominantly occurs via…