Search results for "character"
showing 10 items of 2956 documents
Tetra and pentaquarks from the molecular perspective
2019
We present results for the analysis of the B+ → J/ψϕK+ which shows the contribution of two resonances, the X(4140) and X(4160) and a cusp at the $D_s^*\bar D_s^*$ threshold tied to the molecular character of the X(4160) resonance. In the second part we present the results for the theoretical approach to the new Ωcstates from the molecular perspective. In both cases we compare with results of the LHCb collaboration.
Dynamics of distorted and undistorted soliton molecules in a mode-locked fiber laser
2019
Recent developments in real-time ultrafast measurement techniques have enabled us to prove experimentally that soliton molecules execute internal motions with some aspects similar to those of a matter molecule. Such an analogy between the dynamics of soliton molecules and the dynamics of matter molecules is based on the assumption that the dissipative solitons constituting a molecule are rigid entities sharing a common profile. Whereas this assumption drastically reduces the number of degrees of freedom, it does not hold true in general and we demonstrate that it overlooks some of the essential dynamical features of the soliton molecule. We present a theoretical study based on the principle…
Limits in the characteristic function description of non-Lindblad-type open quantum systems
2005
In this paper I investigate the usability of the characteristic functions for the description of the dynamics of open quantum systems focussing on non-Lindblad-type master equations. I consider, as an example, a non-Markovian generalized master equation containing a memory kernel which may lead to nonphysical time evolutions characterized by negative values of the density matrix diagonal elements [S.M. Barnett and S. Stenholm, Phys. Rev. A {\bf 64}, 033808 (2001)]. The main result of the paper is to demonstrate that there exist situations in which the symmetrically ordered characteristic function is perfectly well defined while the corresponding density matrix loses positivity. Therefore no…
Characterization of Hong-Ou-Mandel bunched states by quantum homodyne tomography
2014
We experimentally demonstrate quantum homodyne tomography of Hong-Ou-Mandel bunched states, which are created by dynamically adjusting emission timings of two heralded single photons using coupled cavities.
On the Measurements of Numerical Viscosity and Resistivity in Eulerian MHD Codes
2016
We propose a simple ansatz for estimating the value of the numerical resistivity and the numerical viscosity of any Eulerian MHD code. We test this ansatz with the help of simulations of the propagation of (magneto)sonic waves, Alfven waves, and the tearing mode instability using the MHD code Aenus. By comparing the simu- lation results with analytical solutions of the resistive-viscous MHD equations and an empirical ansatz for the growth rate of tearing modes we measure the numerical viscosity and resistivity of Aenus. The comparison shows that the fast-magnetosonic speed and wavelength are the characteristic velocity and length, respectively, of the aforementioned (relatively simple) syst…
Information processing in nuclear magnetic resonance imaging.
1988
An extended image analysis and classification system is presented to discuss the principal composition of the components as well as the methods of its realization in the field of reference based NMR diagnostics and tissue characterization.
Characterization of Current Transformers in the Presence of Harmonic Distortion
2008
The CTs performance under distorted conditions are usually characterized by means of the frequency response test. In this paper a new way to characterize CTs, closer to real operative conditions, is proposed. The harmonic phase angle and ratio errors are measured when the CTs are excited with a nonsinusoidal current composed of a fundamental and one harmonic, with adjustable phase shift. The errors measured using the new approach were found larger than the ones obtained with the frequency response. This suggests that frequency response is not a reliable method to evaluate the CT performance under distorted conditions.
Generalized Buckley–Leverett theory for two-phase flow in porous media
2011
Hysteresis and fluid entrapment pose unresolved problems for the theory of flow in porous media. A generalized macroscopic mixture theory for immiscible two-phase displacement in porous media (Hilfer 2006b Phys. Rev. E 73 016307) has introduced percolating and nonpercolating phases. It is studied here in an analytically tractable hyperbolic limit. In this limit a fractional flow formulation exists, that resembles the traditional theory. The Riemann problem is solved analytically in one dimension by the method of characteristics. Initial and boundary value problems exhibit shocks and rarefaction waves similar to the traditional Buckley-Leverett theory. However, contrary to the traditional th…
On the super-energy radiative gravitational fields
2012
We extend our recent analysis (Ferrando J J and S\'aez J A 2012 Class. Quantum Grav. 29 075012) on the Bel radiative gravitational fields to the super-energy radiative gravitational fields defined by Garc\'{\i}a-Parrado (Class. Quantum Grav. 25 015006). We give an intrinsic characterization of the {\it new radiative fields}, and consider some distinguished classes of both radiative and non radiative fields. Several super-energy inequalities are improved.
A covariant determination of the Weyl canonical frames in Petrov type I spacetimes
1997
A covariant algorithm is given to obtain principal 2-forms, Debever null directions and canonical frames associated with Petrov type I Weyl tensors. The relationship between these Weyl elements is explained, and their explicit expressions depending on Weyl invariants are obtained. These results are used to determine a cosmological observer in type I universes, and their usefulness in spacetime intrinsic characterization is shown.