Analysis of the strong coupling constant GDs∗DsϕG_{D_{s}^{*}D_{s}\phi} and the decay width of Ds∗→DsγD_{s}^{*}\rightarrow D_{s}\gamma with QCD sum rules

In this article, we calculate the form factors and the coupling constant of the vertex $D_{s}^{*}D_{s}\phi$ using the three-point QCD sum rules. We consider the contributions of the vacuum condensates up to dimension $7$ in the operator product expansion(OPE). And all possible off-shell cases are considered, $\phi$, $D_{s}$ and $D_{s}^{*}$, resulting in three different form factors. Then we fit the form factors into analytical functions and extrapolate them into time-like regions, which giving the coupling constant for the process. Our analysis indicates that the coupling constant for this vertex is $G_{Ds*Ds\phi}=4.12\pm0.70 GeV^{-1}$. The results of this work are very useful in the other phenomenological analysis. As an application, we calculate the coupling constant for the decay channel $D_{s}^{*}\rightarrow D_{s}\gamma$ and analyze the width of this decay with the assumption of the vector meson dominance of the intermediate $\phi(1020)$. Our final result about the decay width of this decay channel is $\Gamma=0.59\pm0.15keV$.Comment: arXiv admin note: text overlap with arXiv:1501.03088 by other author

Magnetoresistance of atomic-scale electromigrated nickel nanocontacts

We report measurements of the electron transport through atomic-scale constrictions and tunnel junctions between ferromagnetic electrodes. Structures are fabricated using a combination of e-beam lithography and controlled electromigration. Sample geometries are chosen to allow independent control of electrode bulk magnetizations. As junction size is decreased to the single channel limit, conventional anisotropic magnetoresistance (AMR) increases in magnitude, approaching the size expected for tunneling magnetoresistance (TMR) upon tunnel junction formation. Significant mesoscopic variations are seen in the magnitude and sign of the magnetoresistance, and no evidence is found of large ballistic magnetoresistance effects.Comment: 3 pages, 3 figure

Transport Properties in the "Strange Metal Phase" of High Tc Cuprates: Spin-Charge Gauge Theory Versus Experiments

The SU(2)xU(1) Chern-Simons spin-charge gauge approach developed earlier to describe the transport properties of the cuprate superconductors in the ``pseudogap'' regime, in particular, the metal-insulator crossover of the in-plane resistivity, is generalized to the ``strange metal'' phase at higher temperature/doping. The short-range antiferromagnetic order and the gauge field fluctuations, which were the key ingredients in the theory for the pseudogap phase, also play an important role in the present case. The main difference between these two phases is caused by the existence of an underlying statistical $\pi$-flux lattice for charge carriers in the former case, whereas the background flux is absent in the latter case. The Fermi surface then changes from small ``arcs'' in the pseudogap to a rather large closed line in the strange metal phase. As a consequence the celebrated linear in T dependence of the in-plane and out-of-plane resistivity is shown explicitly to recover. The doping concentration and temperature dependence of theoretically calculated in-plane and out-of-plane resistivity, spin-relaxation rate and AC conductivity are compared with experimental data, showing good agreement.Comment: 14 pages, 5 .eps figures, submitted to Phys. Rev. B, revised version submitted on 24 Oc

Fractional exclusion and braid statistics in one dimension: a study via dimensional reduction of Chern-Simons theory

The relation between braid and exclusion statistics is examined in one-dimensional systems, within the framework of Chern-Simons statistical transmutation in gauge invariant form with an appropriate dimensional reduction. If the matter action is anomalous, as for chiral fermions, a relation between braid and exclusion statistics can be established explicitly for both mutual and nonmutual cases. However, if it is not anomalous, the exclusion statistics of emergent low energy excitations is not necessarily connected to the braid statistics of the physical charged fields of the system. Finally, we also discuss the bosonization of one-dimensional anyonic systems through T-duality.Comment: 19 pages, fix typo

On the Relation of Hard X-ray Peak Flux and Outburst Waiting Time in the Black Hole Transient GX 339-4

Aims. In this work we re-investigated the empirical relation between the hard X-ray peak flux and the outburst waiting time found previously in the black hole transient GX 339-4. We tested the relation using the observed hard X-ray peak flux of the 2007 outburst of GX 339-4, clarified issues about faint flares, and estimated the lower limit of hard X-ray peak flux for the next outburst. Methods. We included Swift/BAT data obtained in the past four years. Together with the CGRO/BATSE and RXTE/HEXTE light curves, the observations used in this work cover a period of 18 years. Results. The observation of the 2007 outburst confirms the empirical relation discovered before. This strengthens the apparent link between the mass in the accretion disk and the peak luminosity of the brightest hard state that the black hole transient can reach. We also show that faint flares with peak fluxes smaller than about 0.12 crab do not affect the empirical relation. We predict that the hard X-ray peak flux of the next outburst should be larger than 0.65 crab, which will make it at least the second brightest in the hard X-ray since 1991.Comment: 4 pages, 3 figures, accepted by A&