New distributed offline processing scheme at Belle

The offline processing of the data collected by the Belle detector has been recently upgraded to cope with the excellent performance of the KEKB accelerator. The 127/fb of data (120 TB on tape) collected between autumn 2003 and summer 2004 has been processed in 2 months, thanks to the high speed and stability of the new, distributed processing scheme. We present here this new processing scheme and its performance.Comment: 4 pages, 8 figures, uses CHEP2004.cl

Flavor Mixing in the Gauge-Higgs Unification

Gauge-Higgs unification is the fascinating scenario solving the hierarchy problem without supersymmetry. In this scenario, the Standard Model (SM) Higgs doublet is identified with extra component of the gauge field in higher dimensions and its mass becomes finite and stable under quantum corrections due to the higher dimensional gauge symmetry. On the other hand, Yukawa coupling is provided by the gauge coupling, which seems to mean that the flavor mixing and CP violation do not arise at it stands. In this talk, we discuss that the flavor mixing is originated from simultaneously non-diagonalizable bulk and brane mass matrices. Then, this mechanism is applied to various flavor changing neutral current (FCNC) processes via Kaluza-Klein (KK) gauge boson exchange at tree level and constraints for compactification scale are obtained.Comment: 5 pages, prepared for the proceedings of the International Workshop on Grand Unified Theories (GUT2012) held at Yukawa Institute for Theoretical Physics, March 15-17 2012, Kyoto, Japa

Magnetic-field effects on the charge-spin stripe order in La-214 high-Tc cuprates

Magnetic-field effects on the charge-spin stripe order in La-214 high-Tc cuprates have been investigated from measurements of the in-plane electrical-resistivity, Rho_ab_. In La_2-x_Ba_x_CuO_4_ with x=0.10 and La_2-x_Sr_x_CuO_4_ with x=0.115 where the incommensurate charge peaks are weak and unobservable in zero field in elastic neutron-scattering measurements, respectively, the normal-state value of Rho_ab_ at low temperatures markedly increases with increasing field up to 27 T. For La_2-x_Ba_x_CuO_4_ with x=0.11 and Zn-substituted La_2-x_Sr_x_Cu_1-y_Zn_y_O_4_ with x=0.115 and y=0.02 where the charge stripe order is fairly stabilized in zero field, on the other hand, the increase in Rho_ab_ with increasing field is negligibly small. In conclusion, when the charge-spin stripe order is not fully stable in zero field, magnetic field operates to stabilize the charge-spin stripe order. The value of Rho_ab_ increases with increasing field depending on the stability of the charge stripe order.Comment: 4 pages, 2 figures, Proceedings of Yamada Conference LX on Research in High Magnetic Fields (RHMF2006) (Satellite of ICM2006

Magnetic-field effects on the in-plane electrical resistivity in the single-crystal La2−x_{2-x}Bax_xCuO4_4 and La1.6−x_{1.6-x}Nd0.4_{0.4}Srx_xCuO4_4 around x=1/8x=1/8: Relating to the field-induced stripe order

Temperature dependence of the in-plane electrical resistivity, $\rho_{\rm ab}$, in various magnetic fields has been measured in the single-crystal La$_{2-x}$Ba$_x$CuO$_4$ with $x=0.08$, 0.10, 0.11 and La$_{1.6-x}$Nd$_{0.4}$Sr$_x$CuO$_4$ with $x=0.12$. It has been found that the superconducting transition curve shows a so-called fan-shape broadening in magnetic fields for $x=0.08$, while it shifts toward the low-temperature side in parallel with increasing field for $x=0.11$ and 0.12 where the charge-spin stripe order is formed at low temperatures. As for $x=0.10$, the broadening is observed in low fields and it changes to the parallel shift in high fields above 9 T. Moreover, the normal-state value of $\rho_{\rm ab}$ at low temperatures markedly increases with increasing field up to 15 T. It is possible that these pronounced features of $x=0.10$ are understood in terms of the magnetic-field-induced stabilization of the stripe order suggested from the neutron-scattering measurements in the La-214 system. The $\rho_{\rm ab}$ in the normal state at low temperatures has been found to be proportional to ln(1/$T$) for $x=0.10$, 0.11 and 0.12. The ln(1/$T$) dependence of $\rho_{\rm ab}$ is robust even in the stripe-ordered state.Comment: 6 pages, 4 figures, ver. 2 has been accepted for publication in Phys. Rev.

Destruction of chain-superconductivity in YBa_2Cu_4O_8 in a weak magnetic field

We report measurements of the temperature dependent components of the magnetic penetration depth {\lambda}(T) in single crystal samples of YBa_2Cu_4O_8 using a radio frequency tunnel diode oscillator technique. We observe a downturn in {\lambda}(T) at low temperatures for currents flowing along the b and c axes but not along the a axis. The downturn in {\lambda}_b is suppressed by a small dc field of ~0.25 T. This and the zero field anisotropy of {\lambda}(T) likely result from proximity induced superconducting on the CuO chains, however we also discuss the possibility that a significant part of the anisotropy might originate from the CuO2 planes.Comment: 5 page

Stability Analysis of Eutrophication Models

In this paper characteristics of two eutrophication models are investigated with phase plane analysis of the equilibrium states of the system. Possible patterns of the system's behaviour and their relations to ranges of parameters are shown. The results are used to evaluate the effects of disturbances to the system. Finally, the effects of diffusion on the system's behaviour are discussed and some numerical results are presented