Hyperon Polarization from Unpolarized pp and ep Collisions

Cross section formulas for the $\Lambda$ polarization in $pp\to\Lambda^\uparrow(\ell_T)X$ and $ep\to\Lambda^\uparrow(\ell_T)X$ are derived and its characteristic features are discussed.Comment: 5 pages in LaTex. Talk presented at SPIN'02 held at BNL from Sep. 9 to 14, 200

Novel Master Formula for Twist-3 Soft-Gluon-Pole Mechanism to Single Transverse-Spin Asymmetry

We prove that twist-3 soft-gluon-pole (SGP) cross section for single spin asymmetries is determined by a certain ``primordial'' twist-2 cross section up to kinematic and color factors in the leading order perturbative QCD. This unveils universal structure behind the SGP cross sections in a variety of hard processes, and also the special role of the scale invariance in the corresponding primordial cross section, which leads to remarkable simplification of the SGP cross sections for the production of massless particle, such as those for pion production p^\uparrow p \to \pi X and direct-photon production p^\uparrow p \to \gamma X.Comment: 4 pages, 4 eps figures. To appear in the proceedings of 15th International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2007), Munich, Germany, 16-20 Apr 200

Probing multigluon correlations through single spin asymmetries in pp collisions

We study the single spin asymmetries for the $D$-meson production, Drell-Yan lepton-pair production and the direct-photon production in the $pp$ collision induced by the twist-3 three-gluon correlation functions in the transversely polarized nucleon. We present a corresponding polarized cross section formula in the leading-order with respect to the QCD coupling and a model calculation for the asymmetries, illustrating the sensitivity to the form of the correlation functions.Comment: Proceedings of the talk presented at the 8th Circum-Pan-Pacific Symposium on High Energy Spin Physics: PacSPIN2011, Cairns, Australia, June 20-24, 2011. 6 pages, 3 figure

Q2Q^2 evolution of chiral-odd twist-3 distribution e(x,Q2)e(x,Q^2)

We study the $Q^2$ dependence of the chiral-odd twist-3 distribution $e(x,Q^2)$.The anomalous dimension matrix for the corresponding twist-3 operators is calculated in the one-loop level. This study completes the calculation of the anomalous dimension matrices for all the twist-3 distributions together with the known results for the other twist-3 distributions $g_2(x,Q^2)$ and $h_L(x,Q^2)$. We also have confirmed that in the large $N_c$ limit the $Q^2$-evolution of $e(x,Q^2)$ is wholely governed by the lowest eigenvalue of the anomalous dimension matrix which takes a very simple analytic form as in the case of $g_2$ and $h_L$.Comment: 16 pages LaTeX, 4 postscript figure