Flavor Dependence of T-odd PDFs

Abstract

The flavor dependence of the naive time reversal odd (``T-odd'') parton distributions for $u$- and $d$-quarks are explored in the spectator model. The flavor dependence of $h_{1}^{\perp}$ is of significance for the analysis of the azimuthal $\cos(2φ)$ asymmetries in unpolarized SIDIS and DY-processes, as well as for the overall physical understanding of the distribution of transversely polarized quarks in unpolarized nucleons. As a by-product of the formalism, we calculate the chiral-odd but ``T-even'' function $h_{1L}^{\perp}$ which enables us to present a prediction for the single spin asymmetry $A_{UL}^{\sin(2φ)}$ for a longitudinally polarized target in SIDIS.

Figures (4)

• Figure 1: Different vertices for the axial-vector diquark and contribution of the gauge link in the one-gluon approximation.
• Figure 2: The unpolarized up and down quark distributions functions (left) versus $x$ compared to the low scale parameterization of GRV Gluck:1998xa. The half moment of the Sivers function (center-left) and Boer-Mulders function (center-right) and the unpolarized up and down quark distributions ($\kappa=1.0$). The half-moment (left) and first moments (right) of the Boer-Mulders and Sivers functions versus $x$ fitted to extractions from data were presented in Ref. Anselmino:2005an
• Figure 3: The $\cos2\phi$ asymmetry for and $\pi^{\pm}$ as a function of $P_{T}$ at JLAB $12\textrm{GeV}$ and HERMES (center) kinematics. Right: $\cos2\phi$ asymmetry for $\pi^{\pm}$ as a function of $x$ at JLAB $12\textrm{GeV}$ and HERMES kinematics.
• Figure 4: Left Panel: The half-moment of $xh_{1L}^{\perp(1/2)}$ versus $x$ compared to the unpolarized up and down quark distribution functions. Right Panel: The $\sin2\phi$ asymmetry for $\pi^{+}$ and $\pi^{-}$ as a function of $x$ at JLAB $12\textrm{GeV}$ kinematics.