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

New Heavy-Light Mesons QqˉQ\bar q

We succeed in reproducing the $\ell=1$ $B$ mesons, $B_1(5720)$, $B_2^*(5745)$, and $B_{s2}^*(5839)$ that are recently reported by D0 and CDF, by using our semirelativistic quark potentila model, which also succeeded in predicting the mass spectra of the narrow $D_{sJ}$ as well as broad $D_0^*(0^+)$ and $D_1'(1^+)$ particles a couple of years ago. Mass of higher excited states ($\ell=1, 2$) of $B$ and $B_s$ mesons, which are not yet observed, is also predicted at the first order in $p/m_b$. We find the corresponding $B_{sJ}$ are below $BK/B^*K$ threshold and should have narrow decay widths contrary to most other predictions. Also already established states ($\ell=0$ and $\ell=1$) of $D$, $D_s$, $B$, and $B_s$ heavy mesons are simultaneously reproduced in good agreement with experimental data within one percent of accuracy. To calculate these $D/D_s$ and $B/B_s$ heavy mesons we use different values of strong coupling $\alpha_s$ which conforms to a notion of running coupling.Comment: 14 pages, 4 figures, references correcte