Probing the deuteron structure at small NN distances by antiproton-deuteron annihilation

The production of pions by antiproton-deuteron annihilation at rest is analyzed. Assuming the possible existence of two delta-isobars in a deuteron some enhancement in the distribution over the invariant mass of two negative charged pions is predicted.Comment: 12 pages, Latex and Postscrip

An evolution equation as the WKB correction in long-time asymptotics of Schrodinger dynamics

We consider 3d Schrodinger operator with long-range potential that has short-range radial derivative. The long-time asymptotics of non-stationary problem is studied and existence of modified wave operators is proved. It turns out, the standard WKB correction should be replaced by the solution to certain evolution equation.Comment: This is a preprint of an article whose final and definitive form has been published in Comm. Partial Differential Equations, available online at http://www.informaworld.co

Biased diffusion in a piecewise linear random potential

We study the biased diffusion of particles moving in one direction under the action of a constant force in the presence of a piecewise linear random potential. Using the overdamped equation of motion, we represent the first and second moments of the particle position as inverse Laplace transforms. By applying to these transforms the ordinary and the modified Tauberian theorem, we determine the short- and long-time behavior of the mean-square displacement of particles. Our results show that while at short times the biased diffusion is always ballistic, at long times it can be either normal or anomalous. We formulate the conditions for normal and anomalous behavior and derive the laws of biased diffusion in both these cases.Comment: 11 pages, 3 figure

Coulomb's law modification in nonlinear and in noncommutative electrodynamics

We study the lowest-order modifications of the static potential for Born-Infeld electrodynamics and for the $\theta$-expanded version of the noncommutative U(1) gauge theory, within the framework of the gauge-invariant but path-dependent variables formalism. The calculation shows a long-range correction ($1/r^5$-type) to the Coulomb potential in Born-Infeld electrodynamics. However, the Coulomb nature of the potential (to order $e^2$) is preserved in noncommutative electrodynamics.Comment: 14 pages, 1 figur

Analytically solvable model of a driven system with quenched dichotomous disorder

We perform a time-dependent study of the driven dynamics of overdamped particles which are placed in a one-dimensional, piecewise linear random potential. This set-up of spatially quenched disorder then exerts a dichotomous varying random force on the particles. We derive the path integral representation of the resulting probability density function for the position of the particles and transform this quantity of interest into the form of a Fourier integral. In doing so, the evolution of the probability density can be investigated analytically for finite times. It is demonstrated that the probability density contains both a $\delta$-singular contribution and a regular part. While the former part plays a dominant role at short times, the latter rules the behavior at large evolution times. The slow approach of the probability density to a limiting Gaussian form as time tends to infinity is elucidated in detail.Comment: 18 pages, 5 figure

The arions generation by magnetodipole waves of pulsars and magnetars in a constant magnetic field

The influence of the gravitational fields of pulsars and magnetars on the arion emission during the propagation of magnetodipole waves in a constant magnetic field has been evaluated. The solution of the equation was obtained and the flux of arions emitted by magnetodipole waves during their propagation in a constant magnetic field was found. It is shown that the amplitude of the born arion wave at a distance from the source of magnetodipole radiation of a pulsar or magnetar $(r\to\infty)$ in the considered case tends to a constant value. The intensity of the arion emission in the solid angle element and the amount of arion energy $\overline{I}$, emitted in all directions per unit time grow quadratically with increasing distance, traveled by the magnetodipole radiation of a pulsar or magnetar in a constant magnetic field. Such growth of the energy of the born arion wave is due to the fact that in the considered problem constant magnetic field is defined in the whole space. In reality, the galactic and intergalactic magnetic fields can be represented in this form only in regions of space of finite dimensions, outside of which the force lines of their induction vector are curved. Therefore, it is possible to apply these results only in a region of space for which $r\leq L_{coh}<\infty$, where $L_{coh}$ is the coherence length, the distance at which the force lines of the induction vector can be considered as straight lines. An estimate for the value of the coupling constant of photons with arions is obtained

Arrival time distribution for a driven system containing quenched dichotomous disorder

We study the arrival time distribution of overdamped particles driven by a constant force in a piecewise linear random potential which generates the dichotomous random force. Our approach is based on the path integral representation of the probability density of the arrival time. We explicitly calculate the path integral for a special case of dichotomous disorder and use the corresponding characteristic function to derive prominent properties of the arrival time probability density. Specifically, we establish the scaling properties of the central moments, analyze the behavior of the probability density for short, long, and intermediate distances. In order to quantify the deviation of the arrival time distribution from a Gaussian shape, we evaluate the skewness and the kurtosis.Comment: 18 pages, 5 figure

Magnetization of nanoparticle systems in a rotating magnetic field

The investigation of a sizable thermal enhancement of magnetization is put forward for uniaxial ferromagnetic nanoparticles that are placed in a rotating magnetic field. We elucidate the nature of this phenomenon and evaluate the resonant frequency dependence of the induced magnetization. Moreover, we reveal the role of magnetic dipolar interactions, point out potential applications and reason the feasibility of an experimental observation of this effect.Comment: 10 pages, 2 figure

On the theory of the vortex state in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase

We demonstrate that the vortex state in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase may be very different depending on the field orientation relative to the crystalline axes. We calculate numerically the upper critical field near the tricritical point taking into account the modulation of the order parameter along the magnetic field as well as the higher Landau levels. For s-wave superconductors with the anisotropy described by an elliptical Fermi surface we propose a general scheme of the analysis of the angular dependence of upper critical field at all temperatures on the basis of the exact solution for the order parameter. Our results show that the transitions (with tilting magnetic field) between different types of mixed states may be a salient feature of the FFLO phase. Moreover we discuss the reasons for the first-order phase transition into the FFLO state in the case of CeCoIn5 compound.Comment: 7 figure

Analyticity and uniform stability in the inverse spectral problem for Dirac operators

We prove that the inverse spectral mapping reconstructing the square integrable potentials on [0,1] of Dirac operators in the AKNS form from their spectral data (two spectra or one spectrum and the corresponding norming constants) is analytic and uniformly stable in a certain sense.Comment: 19 page