Polarized s-quark Distribution in Charmed Hadron Leptoproduction

In order to extract the polarized strange quark density in proton, we studied the semi-inclusive $\Lambda_c$/$\bar{\Lambda}_c$ leptoproduction in charged current DIS at THERA energies. We indicate that measurements of the spin correlation between the incident proton and the produced $\Lambda_c$/$\bar{\Lambda}_c$ baryon gives us information about the polarized strange quark distribution.Comment: 6 pages including 2 figures. Talk given at SPIN2001 (The 3rd Circum-Pan-Pacific Symposium on "High Energy Spin Physics"), Beijing, China, Oct. 200

Lambda_c^+ production in polarized pp scattering and polarized gluon distribution

To extract information about the polarized gluon distribution, \dg, in the nucleons, we propose Lambda_c^+ productions in polarized pp scattering, p + \vec{p} \to \vec{Lambda_c^+} + X, which will be observed at RHIC experiment starting soon. For this process, we have calculated the spin correlation differential cross section, d\Delta \sigma/d\pt, and the spin correlation asymmetry defined by \A_ll \equiv [ d \Delta \sigma / d \pt ] / [ d \sigma / d\pt ]. We have found that the \A_ll is sensitive to the polarized gluon distribution in the nucleon and thus the process is promising for testing \Delta G(x,Q^2).Comment: 10 pages, LaTex2e, 6 figures.(V2: typos fixed. Conclusions unchanged

Is the Z^+(4430) a radially excited state of D_s?

We present the interpretation that the recently discovered Z^+(4430) by the Belle Collaboration can be a radial excitation of the cs-bar state. We give an explicit cs-bar candidate for this state by calculating the mass value in our semirelativistic quark potential model and also give a natural interpretation on the reason why the decay mode Z-> J/\psi \pi^+ has not yet been seen while Z-> \psi' \pi can be seen.Comment: 6 pages, 4 figure