Charmed Hadron Production in Polarized pp Reactions as a Probe of Polarized Gluons in the Proton

To probe the behavior of polarized gluons in the proton, we propose the charmed hadron, such as Lambda_c and D^*, production in the forthcoming RHIC experiments. We found that the spin correlation between the target proton and the produced Lambda_c baryon might be a good signal for testing models of the polarized gluon distribution in the proton.Comment: 1+5 pages, 4 figures, Contributed to 16th International Conference on Particles and Nuclei (PANIC 02), Osaka, Japan, 30 Sep - 4 Oct 200

Full analysis of general non-standard tbW couplings

Possible non-standard couplings which could contribute to the t -> b W process are studied based on the effective-Lagrangian approach. The corresponding effective Lagrangian consists of four kinds of dimension-6 effective operators, each of which has an independent coupling constant. In this analysis, all those couplings are treated as complex numbers and constraints on them are estimated by using recent experimental data from the LHC. We point out that the resultant constraints on those couplings are still not that strong because contributions from some couplings can work oppositely with each other.Comment: One comment and two related references added. Final version to appear in Phys.Lett.

Probing Polarized Gluon Distributions through Charmed Hadron Production in Polarized pp Collisions at BNL--RHIC Energy

In order to extract information about behavior of polarized gluons in the nucleon, charmed hadron productions, i.e. D* meson and Lambda_c baryon productions, are studied in polarized pp reactions at BNL-RHIC energy. For these processes, the spin correlation asymmetry D_{LL} between the target proton and the produced charmed hadron, and its statistical sensitivity delta D_{LL} are calculated. From analyses on these processes, we found that the pseudo-rapidity distribution of D_{LL} in the limited transverse momentum region is quite effective for distinguishing the model of polarized gluons as well as the model of spin-dependent fragmentation functions.Comment: 1+14 pages, 14 figures, added references and comments, To appear in Int. Journal of Modern Phys.

Final charged-lepton angular distribution and possible anomalous top-quark couplings in p p -> t tbar X -> l^+ X'

Possible anomalous (or nonstandard) top-quark interactions with the gluon and those with the W boson induced by SU(3) x SU(2) x U(1) gauge-invariant dimension-6 effective operators are studied in p p -> t tbar X -> l^+ X' (l=e or mu) at the Large Hadron Collider (LHC). The final charged-lepton (l^+) angular distribution is first computed for nonvanishing nonstandard top-gluon and top-W couplings with a cut on its transverse momentum. The optimal-observable procedure is then applied to this distribution in order to estimate the expected statistical uncertainties in measurements of those couplings that contribute to this process in the leading order.Comment: latex_2e, 14 pages, 4 eps figure

Charmed Hadron Production in Polarized pp Collisions

To extract information about polarized gluons in the proton, production of charmed hadrons, in particular, \Lambda_c^+ baryon in pp collisions was studied. We calculated the transverse momentum distribution and the pseudo-rapidity distribution of the spin correlation asymmetry A_{LL} between the initial proton and the produced \Lambda_c^+. Those statistical sensitivities were also calculated under the condition of RHIC experiment. We found that the pseudo-rapidity distribution of A_{LL} is promising for testing the model of polarized gluons in the proton and also the spin-dependent fragmentation model of a charm quark decaying into \Lambda_c^+ baryon.Comment: 1+6 pages, Latex2e, 4 eps figures, Talk given at SPIN 2002, Brookhaven National Laboratory, September 9-13, 2002, To appear in the Proceeding

Exploring anomalous top interactions via the final lepton in ttbar productions/decays at hadron colliders

We study momentum distributions of the final-state charged lepton in ppbar/pp --> ttbar --> l^+ X (l=e or mu) at hadron colliders, i.e., Tevatron and Large Hadron Collider (LHC) in order to explore possible new-physics effects in the top-quark sector. Assuming general model-independent ttbar g + ttbar gg and tbW interactions beyond the standard model, we first derive analytical formulas for the corresponding parton-parton processes. We then compute the lepton angular, energy and transverse-momentum distributions in ppbar/pp collisions to clarify how they are affected by those anomalous couplings.Comment: Journal information added. Title slightly changed in the published version (top interaction --> top-quark interaction). One typo in eqs.(15)-(19) corrected (dE_l c_l --> dE_l dc_l

Local finance-growth nexus: Does bank ownership matter?

This paper examines the effects of the ownership form of banks on the finance-growth nexus in Japan. If the cooperative ownership of banks has comparative advantages in local financial development, the failure of a cooperative bank should be more harmful than that of a commercial bank. The evidence in this paper, however, provokes skepticism to this view, suggesting less efficient operation of some cooperative banks in local communities probably due to weak mechanisms for management discipline.Banking crisis, Cooperative bank, Bank ownership, Financial development, Local growth, Japan