Plastic deformation of niobium

Imperial Users onl

K0ΛK^0\Lambda Photoproduction with Nucleon Resonances

We investigate the reaction mechanism of $K^0 \Lambda$ photoproduction off the neutron target, i.e., $\gamma n \to K^0 \Lambda$, in the range of $W\approx 1.6-2.2$ GeV. We employ an effective Lagrangian method at the tree-level Born approximation combining with a Regge approach. As a background, the $K^*$-Reggeon trajectory is taken into account in the $t$ channel and $\Lambda$ and $\Sigma$ hyperons in the $u$-channel Feynman diagram. In addition, the role of various nucleon resonances listed in the Particle Data Group (PDG) is carefully scrutinized in the $s$ channel where the resonance parameters are extracted from the experimental data and constituent quark model. We present our numerical results of the total and differential cross sections and compare them with the recent CLAS data. The effect of the narrow nucleon resonance $N(1685,1/2^+)$ on cross sections is studied in detail and it turns out that its existence is essential in $K^0 \Lambda$ photoproduction to reproduce the CLAS data.Comment: 4 pages, 3 figures, Proceedings of "8th International Conference on Quarks and Nuclear Physics (QNP2018)", November 13-17, 2018, Tsukuba, Japa

East Asia's dynamic development model and the Republic of Korea's experiences

No region has been more dynamic in recent years than East Asia. Despite its successful economic development, evaluations of the East Asian development model have often been capricious, shifting from"miracle"to"cronyism."How can we explain East Asia's ups and downs consistently? To respond to this challenge, it is necessary to study the progress of East Asian development and to trace the influence of Asian cultural values. This study mainly focuses on cultural aspects of economic progress and analyzes East Asia's philosophical and historical backgrounds to explain the dynamic process. East Asians believe that balance between opposite but complementary forces, Yin and Yang, will ensure social stability and progress. Through repeated rebalancing to maintain harmony, the society comes to maturity. In traditional East Asian societies, a balance was maintained between Confucianism (Yang) and Taoism, Buddhism, and other philosophies (Yin). In modern societies, the challenge is to balance traditional systems (Yang) and Western style capitalism (Yin). This East Asian development model explains the Republic of Korea's rise, fall, and recovery. Korea was a poor country until the early 1960s, during the time when spiritualism (Yang) dominated. From the 1960s through the 1980s, Korea achieved rapid growth by finding a new balance and moving toward materialism (Yin) from spiritualism (Yang). But the failure to maintain a harmonious balance between cooperative systems and collectivism (Yang) and individualism (Yin) led to major weaknesses in labor and financial markets that contributed significantly to the financial crisis in 1997. As Korea arrived at a new balance by instituting reform programs, the venture-oriented information and communication technology (ICT) industry blossomed and led to a rapid economic recovery. Since 2000, domestic financial scandals and political corruption have emerged as new social issues. Korea's next challenge is to find a new harmonization between morality (Yang) and legal frameworks (Yin).Environmental Economics&Policies,Public Health Promotion,Ethics&Belief Systems,Earth Sciences&GIS,Decentralization,Earth Sciences&GIS,Ethics&Belief Systems,Economic Theory&Research,Environmental Economics&Policies,Health Economics&Finance

Heavy pentaquark states Pc(4380)P_c(4380) and Pc(4450)P_c(4450) in the J/ψJ/\psi production induced by pion beams off the nucleon

In this study, we investigate the $J/\psi$ production induced by pion beams off the nucleon, particularly the heavy pentaquarks $P_c(4380)$ and $P_c(4450)$ in intermediate states, based on a hybridized Regge model. The process involving $\rho$ and $\pi$ meson exchange in the $t$ channel is considered as background, and the heavy pentaquark exchange is included in the $s$ channel. The coupling constants such as the $\rho NN$ and $\pi NN$ vertices are taken from the $NN$ potentials, whereas those for the $J/\psi\rho\pi$ and $J/\psi\pi\pi$ vertices are determined by using experimental data based on the branching ratios. In order to estimate the $P_c(4380)$ and $P_c(4450)$ coupling constants, we use the experimental upper limit on the total cross section as a guide for the $\pi N\to J/\psi N$ reaction. The background total cross section is the order of $10^{-4}-10^{-3}$ nb. In the vicinity of the heavy pentaquark masses, the total cross section reaches about $1$ nb.Comment: 13 pages, 6 figures. To be published in Phys. Lets.

Electrical Investigation of the Oblique Hanle Effect in Ferromagnet/Oxide/Semiconductor Contacts

We have investigated the electrical Hanle effect with magnetic fields applied at an oblique angle ({\theta}) to the spin direction (the oblique Hanle effect, OHE) in CoFe/MgO/semiconductor (SC) contacts by employing a three-terminal measurement scheme. The electrical oblique Hanle signals obtained in CoFe/MgO/Si and CoFe/MgO/Ge contacts show clearly different line shapes depending on the spin lifetime of the host SC. Notably, at moderate magnetic fields, the asymptotic values of the oblique Hanle signals (in both contacts) are consistently reduced by a factor of cos^2({\theta}) irrespective of the bias current and temperature. These results are in good agreement with predictions of the spin precession and relaxation model for the electrical oblique Hanle effect. At high magnetic fields where the magnetization of CoFe is significantly tilted from the film plane to the magnetic field direction, we find that the observed angular dependence of voltage signals in the CoFe/MgO/Si and CoFe/MgO/Ge contacts are well explained by the OHE, considering the misalignment angle between the external magnetic field and the magnetization of CoFe.Comment: 19 pages, 8 figure