Search results for "TRANSFORMATION"

Systematic study of octet-baryon electromagnetic form factors in covariant chiral perturbation theory

2017

We perform a complete and systematic calculation of the octet-baryon form factors within the fully covariant approach of SU(3) chiral perturbation theory at O(p^3). We use the extended on-mass shell renormalization scheme, and include explicitly the vector mesons and the spin-3/2 decuplet intermediate states. Comparing these predictions with data including magnetic moments, charges, and magnetic radii, we determine the unknown low-energy constants, and give predictions for yet unmeasured observables, such as the magnetic moment of the Sigma^0, and the charge and magnetic radii of the hyperons.

Improved description of the pion-nucleon scattering phenomenology in covariant baryon chiral perturbation theory

2014

We highlight some of the recent advances in the application of chiral effective field theory (chiral EFT) with baryons to the $\pi N$ scattering process. We recall some problems that cast doubt on the applicability of chiral EFT to $\pi N$ and show how the relativistic formalism, once the $\Delta(1232)$-resonance is included as an explicit degree of freedom, solves these issues. Finally it is shown how this approach can be used to extract the $\sigma$-terms from phenomenological information.

Exact analytic expressions for electromagnetic propagation in a finite one-dimensional periodic multilayer

2004

Translation Matrix Formalism has been used to find an exact analytic solution for light propagation in a finite one-dimensional (1-D) periodic stratified structure. This modal approach allows to derive a closed formula for the electric field in every point of the structure, by simply imposing a convenient form for the boundary conditions. As an example it is also shown how to extend this result to gratings featuring defects.

Dynamics of the labyrinthine patterns at the diffuse phase boundaries

2001

The phase diagram of a magnetic colloid in a Hele-Shaw cell is calculated. As a function of the magnetic field strength, of the concentration and of the layer thickness the magnetic colloid can find itself in a stripe phase, the hexagonal phase or in an unmodulated state. Those results allow to interpret experiments observing the transformation of a labyrinthine pattern into a hexagonal structure. This possibility is confirmed directly by the numerical simulation presented here and showing the transformation of the labyrinthine pattern into the hexagonal structure.

Multifractal electronic wave functions in disordered systems

1992

Abstract To investigate the electronic states in disordered samples we diagonalize very large secular matrices corresponding to the Anderson Hamiltonian. The resulting probability density of single electronic eigenstates in 1-, 2-, and 3-dimensional samples is analysed by means of a box-counting procedure. By linear regression we obtain the Lipschitz-Holder exponents and the corresponding singularity spectrum, typical for a multifractal set in each case. By means of a Legendre transformation the mass exponents and the generalized dimensions are derived. Consequences for spectroscopic intensities and transport properties are discussed.

Optical solitons in erbium doped fibers with higher order effects

2000

Abstract We consider the coupled system of higher order nonlinear Schrodinger equation and Maxwell–Bloch (HNLS–MB) equations, which governs the nonlinear wave propagation in erbium doped optical waveguides in presence of important higher order effects. We present the Lax pair and using Backlund transformation exact soliton solutions are generated.

On time-resolved approach for phonon assisted interband transitions

2015

Photoexcited dynamics of electrons and holes in two-band dielectric, with special emphasis on back reaction of phonons are developed by combining the quantum electrodynamics and Baker-Campbell-Hausdorff (BCH) canonical transformation. These methods create an explicit time-domain representation of photoinduced processes and contribute in unifying phonon-assisted description of distribution functions of electron and hole quasiparticles for the description of observable effects of photoinduced processes in dielectrics.

Poincaré's role in the Crémieu-Pender controversy over electric convection

1989

Summary In the course of 1901, V. Cremieu published the results of some experiments carried out to test the magnetic effects of electric convection currents. According to Cremieu, his experiments had proved that convection currents had no magnetic effects and consequently they were not equivalent to conduction currents, that is they were not ‘real’ electric currents. These negative results conflicted with those of well-known experiments carried out by other researchers, in particular with Rowland's experiments, and with Maxwell's, Hertz's and Lorentz's theories, which was more shocking. The publication of Cremieu's experiments raised a controversy which involved directly or indirectly some …

SU(3)-breaking corrections to the hyperon vector coupling f1(0) in covariant baryon chiral perturbation theory

2010

Numerical simulation of free dissipative open quantum system and establishment of a formula for π

2020

We transform the system/reservoir coupling model into a one-dimensional semi-infinite discrete chain with nearest neighbor interaction through a unitary transformation, and, simulate the dynamics of free dissipative open quantum system. We investigate the consequences of such modeling, which is observed as finite size effect causing the recurrence of particle from the end of the chain. Afterwards, we determine a formula for π in terms of the matrix operational form, which indicates a robustness of the connection between quantum physics and basic mathematics. peerReviewed