Superfluid-Mott Insulator Transition of Spin-1 Bosons in an Optical Lattice

We have studied superfluid-Mott insulating transition of spin-1 bosons interacting antiferromagnetically in an optical lattice. We have obtained the zero-temperature phase diagram by a mean-field approximation and have found that the superfluid phase is to be a polar state as a usual trapped spin-1 Bose gas. More interestingly, we have found that the Mott-insulating phase is strongly stabilized only when the number of atoms per site is even.Comment: 9 pages, 1 figur

Spin-charge mixing effects on resonant tunneling in a polarized Luttinger Liquid

We investigate spin-charge mixing effect on resonant tunneling in spin-polarized Tomonaga-Luttinger liquid with double impurities. The mixing arises from Fermi velocity difference between two spin species due to Zeeman effect. Zero bias conductance is calculated as a function of gate voltage $V_{\rm g}$, gate magnetic field $B_{\rm g}$, temperature and magnetic field applied to the system. Mixing effect is shown to cause rotation of the lattice pattern of the conductance peaks in $(V_{\rm g},B_{\rm g})$ plane, which can be observed in experiments. At low temperatures, the contour shapes are classified into three types, reflecting the fact that effective barrier potential is renormalized towards ``perfect reflection'', ``perfect transmission'' and magnetic field induced ``spin-filtering'', respectively.Comment: 10 pages, 4 figures, Sec.I and references largely changed, results for a strong barrier limit added in a new section Sec.I

Bosonic Quartic Couplings at LEP2

We list the set of C and P conserving anomalous quartic vector bosons self-couplings which can be tested at LEP2 through triple vector boson production. We show how this set can be embedded in manifestly SU(2)xU(1) gauge invariant operators exhibiting an SU(2)_c global symmetry. We derive bounds on these various couplings and show the most relevant distributions that can enhance their contribution. We also find that an e+e- collider running at 500 GeV can improve the LEP2 limits by as much as three orders of magnitude.Comment: 21 pages, 7 figure

Discrimination of SUSY breaking models using single-photon processes at future e+e- linear colliders

We examine the single-photon processes in the frame work of supersymmetric models at future e+e- linear colliders. According to the recent experimental achievement, the optimistic polarization degrees for both electron and positron beams are taken into account to enhance the signal-to-noise ratio revealing the observable difference between supersymmetry breaking models. The minimal supergravity model and the minimal SU(5) grand unified model in gaugino mediation have been examined as examples. We see that after several years of accummulating data, the difference of the number of single-photon events between the two models received from the collider would be in excess of three times the statistical error, providing us the possibility to probe which model would be realized in nature. The result is well suitable for the future running of the International Linear Collider.Comment: 14 pages, 4 figures, version to be published in Mod. Phys. Lett.

Numerical simulations of tropical cyclone‐ocean interaction with a high‐resolution coupled model

The tropical cyclone‐ocean interaction was investigated using a high‐resolution tropical cyclone ocean coupled model. The model design consisted of the NOAA Geophysical Fluid Dynamics Laboratory tropical cyclone prediction model which was coupled with a multilayer primitive equation ocean model. Coupling between the hurricane and the ocean models was carried out by passing into the ocean model the wind stress, heat, and moisture fluxes computed in the hurricane model. The new sea surface temperature (SST) calculated by the ocean model was then used in the tropical cyclone model. A set of idealized numerical experiments were performed in which a tropical cyclone vortex was embedded in both easterly and westerly basic flows of 2.5, 5, and 7.5 m s−1 with a fourth experiment run with no basic flow specified initially. The profile of the tangential wind for Hurricane Gloria at 1200 UTC 22, September 1985 was used as the initial condition of the tropical cyclone for each of the experiments. The model ocean was initially horizontally homogenous and quiescent. To clarify the impact of the ocean response to the hurricane\u27s behavior, analogous experiments were also carried out with the SST kept constant (control cases). The experiments indicated that the cooling of the sea surface induced by the tropical cyclone resulted in a significant impact on the ultimate storm intensity due to the reduction of total heat flux directed into the tropical cyclone above the regions of decreased SST. The sea surface cooling produced by the tropical cyclones was found to be larger when the storms moved slower. In the experiments run without an initial basic flow, the maximum SST anomaly was about −5.6°C with a resulting difference in the minimum sea level pressure and maximum surface winds of 16.4 hPa and −7 m s−1, respectively. In contrast, in the experiments run with the 7.5 m s −1 basic flow, the maximum SST anomalies ranged from about 2.6° to 3.0°C with a difference in the minimum sea level pressure and maximum surface winds of about 7.3 hPa and −2.7 m s−1. The tropical cyclone‐ocean coupling significantly influenced the storm track only for the case with no basic flow and the 2.5 m s−1 easterly flow. In these cases the storm with the ocean interaction turned more to the north and east (no basic flow) or the north (2.5 m s−1 easterly flow) of the experiments with constant SST. In the first case, the storm by 72 hours was located over 70 km to the east‐southeast of the control case. A possible explanation for this track deviation is related to a systematic weakening of the mean tangential flow at all radii of the storm due to the interaction with the ocean and resulting alteration of the beta drift

Josephson π\pi-state in superconductor-Luttinger liquid hybrid systems

Josephson current through a Luttinger liquid (LL) under a magnetic field is theoretically studied. We derive an analytical expression of Josephson current for clean interfaces, by using quasiclassical Green's function and functional bosonization procedure. We show that critical currents can be renormalized by electron-electron interactions at perfect transparency when LL is adiabatically connected with superconductors. We also find that a generation of $\pi$-state, due to spin-dependent energy shift in Andreev bound states (ABS), is prohibited even at zero temperature when the strength of repulsive interactions reaches some critical value. The suppression of $\pi$-state is caused by the low energy fluctuations propagating in LL, and making the Zeeman splitting in ABS blurred.Comment: 5 pages, 4figure

Faixas de suficiência de nutrientes em folhas de soja, em Mato Grosso do Sul e Mato Grosso, definidas pelo uso do método DRIS de diagnose do estado nutricional.

Organizado por Odilon Ferreira Saraiva, César de Castro, Regina Maria Villas Bôas de Campos Leite, Fábio Alvares de Oliveira

Resposta do arroz irrigado a doses de nitrogênio e potássio.

bitstream/item/66203/1/31474.pdfFERTBIO

Combination quantum oscillations in canonical single-band Fermi liquids

Chemical potential oscillations mix individual-band frequencies of the de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) magneto-oscillations in canonical low-dimensional multi-band Fermi liquids. We predict a similar mixing in canonical single-band Fermi liquids, which Fermi-surfaces have two or more extremal cross-sections. Combination harmonics are analysed using a single-band almost two-dimensional energy spectrum. We outline some experimental conditions allowing for resolution of combination harmonics

Cluster models of Lambda-Lambda-6He and Lambda-9Be hypernuclei

Configuration space Faddeev calculations are performed for the binding energy of Lambda-Lambda-6He and Lambda-9Be bound states, here considered as alpha-Lambda-Lambda and alpha-alpha-Lambda clusters respectively, in order to study the dependence of the calculated binding energy on the alpha-Lambda potential input. For Lambda-Lambda-6He, using realistic interactions, the uncertainty in extracting the Lambda-Lambda S=L=0 interaction strength does not exceed 0.1 MeV, which is a fraction of the order of magnitude derived for other theoretical uncertainties. For Lambda-9Be, the dependence of the calculated binding energy on the alpha-Lambda potential is considerably larger, of order 1 MeV. Our results for Lambda-9Be suggest that the odd-state alpha-Lambda interaction is substantially reduced with respect to the even-state component.Comment: 16 pages, including 4 figures, typos corrected, slightly revised, accepted to Nuclear Physics