Recent results on PHENIX longitudinal asymmetry measurements

The spin structure of proton has been a long-standing open question for the last decades. Polarized DIS and SIDIS experiments have been the Explorer of the field and providing us the knowledge the part of substructure of the proton spin by its subcomponents. In contrast to well-measured valence quark contribution to the proton spin, polarization of gluons and sea quarks still remain with a large uncertainty. PHENIX experiment has been providing various asymmetry data to introduce new constraints to the proton spin structure, particularly gluon and sea quark polarization in proton spin using the world highest-energy polarized protonproton collider, RHIC. In this report, the latest gluon polarization measurements in PHENIX through various observables are presented. Also preliminary results of W-boson production to measure the sea quark polarization in both central and forward rapidity are presented

Polarization Enhancement of terahertz radiation generated by intrinsic Josephson junctions in a truncated edge square Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} mesa

In this study, we investigated the terahertz radiation from a truncated edge square mesa structure made from a superconducting Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} . Using a commercial software, the polarization characteristics were determined, and introduced, while accounting for the skin effect. The axial ratio was enhanced in the simulation by performing a parametric study on the design.Comment: Proceedings of the 28th International Symposium on Superconductivity, ISS 2015, November 16-18, 2015, Tokyo, Japa

Gluon propagators and center vortices in gluon plasma

We study electric and magnetic components of the gluon propagators in quark-gluon plasma in terms of center vortices by using a quenched simulation of SU(2) lattice theory. In the Landau gauge, the magnetic components of the propagators are strongly affected in the infrared region by removal of the center vortices, while the electric components are almost unchanged by this procedure. In the Coulomb gauge, the time-time correlators, including an instantaneous interaction, also have an essential contribution from the center vortices. As a result, one finds that magnetic degrees of freedom in the infrared region couple strongly to the center vortices in the deconfinement phase.Comment: 12 pages, 11 figure

An optimal maintenance time of automatic monitoring system of ATM with two kinds of breakdowns

AbstractAll automatic teller machines (ATMs) in a bank operate unmanned on weekends and holidays, and an automatic monitoring system continuously watches the operation of ATMs through the telecommunication network. There are two kinds of troubles according to the installed places of ATMs. One is the trouble which occurs inside the branch of a bank where ATMs operate manned except on weekends and holidays, and the other is the one which occurs outside the branch where ATMs always operate unmanned. Two kinds of breakdowns are introduced, and the expected cost for an unmanned operation period is obtained. A maintenance policy which minimizes the expected cost is analytically derived. Finally, a numerical example is given and some useful discussions are made