Search results for "signal processing"
showing 10 items of 2451 documents
Energy- and angle-resolved electron distribution in the photodetachment ofF−
2009
We report calculations of energy- and angle-resolved photoelectron distribution of ${\text{F}}^{\ensuremath{-}}$ irradiated by a linearly strong short infrared pulse, performed by evaluating the photoelectron ejection probability in the framework of a modified Keldysh theory, taking into account the temporal behavior of the pulse and the spatial inhomogeneity of the laser intensity. Results of the calculations are compared with the measurements of the photoelectron angular distribution recently appearing in the literature. The oscillations found in the experimental data are explained in terms of quantum interference effects.
Measurement of the neutrino neutral-current elastic differential cross section on mineral oil atEν∼1 GeV
2010
We report a measurement of the flux-averaged neutral-current elastic differential cross section for neutrinos scattering on mineral oil (CH{sub 2}) as a function of four-momentum transferred squared, Q{sup 2}. It is obtained by measuring the kinematics of recoiling nucleons with kinetic energy greater than 50 MeV which are readily detected in MiniBooNE. This differential cross-section distribution is fit with fixed nucleon form factors apart from an axial mass M{sub A} that provides a best fit for M{sub A}=1.39{+-}0.11 GeV. Using the data from the charged-current neutrino interaction sample, a ratio of neutral-current to charged-current quasielastic cross sections as a function of Q{sup 2} …
Octupolar-Excitation Penning-Trap Mass Spectrometry forQ-Value Measurement of Double-Electron Capture inEr164
2011
The theory of octupolar-excitation ion-cyclotron-resonance mass spectrometry is presented which predicts an increase of up to several orders of magnitude in resolving power under certain conditions. The new method has been applied for a direct Penning-trap mass-ratio determination of the $^{164}\mathrm{Er}\mathrm{\text{\ensuremath{-}}}^{164}\mathrm{Dy}$ mass doublet. $^{164}\mathrm{Er}$ is a candidate for the search for neutrinoless double-electron capture. However, the measured ${Q}_{ϵϵ}$ value of 25.07(12) keV results in a half-life of ${10}^{30}$ years for a 1 eV Majorana-neutrino mass.
Triple magnetopolarons in quantum wells
1997
We derive the equations for eigenstates and eigenenergies of a triple magnetopolaron in quantum-well structures. An iteration procedure for obtaining the wave function and energy including the contributions of diagrams with crossing phonon lines is given. We show that under conditions of exact resonance the middle energy branch of the triply split magnetopolaron state consists of only two out of three bare states. We suggest the experimental verification of this prediction.
Spectroscopic data, spin-orbit functions, and revised analysis of strong perturbative interactions for theA 1Σ+andb 3Πstates of RbCs
2010
The current interest in producing ultracold RbCs molecules by optical excitation from weakly bound Feshbach resonances and stimulated decay to the absolute ground state requires detailed analyses of the intermediate excited states. In this study, we present two sets of experimental Fourier-transform spectroscopic data of the $A{ }^{1}{\ensuremath{\Sigma}}^{+}$-$b{ }^{3}\ensuremath{\Pi}$ complex. The $A$-$b$ mixed vibrational levels are the most likely candidates to be intermediates in the molecular formation. The more recent and more accurate data set is from mixed $A$-$b\ensuremath{\rightarrow}X$ transitions, while the second is derived in large part from $(4){ }^{1}{\ensuremath{\Sigma}}^{…
Nonlinear spectral compression in fibre as a power-limiting device
2017
Spectral compression (SC) by self-phase modulation in optical fibre has been known for a long time and has since been reported for various parameters [1]. In this paper, we analyse the impact of amplitude fluctuations and a degraded optical signal-to-noise ratio (OSNR) of the seed pulses on the SC process by means of extensive nonlinear Schrodinger equation numerical simulation. Remarkably, our results show that the SC is rather stable against these pulse degradation factors, thereby revealing its potential for use in the context of optical regeneration of intensity-modulated signals. We therefore propose an optical scheme combining SC with an optical bandpass filter (OBPF) centred at the c…
Binding of the BDD¯ and BDD systems
2017
We study theoretically the $BD\overline{D}$ and $BDD$ systems to see if they allow for possible bound or resonant states. The three-body interaction is evaluated implementing the fixed center approximation to the Faddeev equations which considers the interaction of a $D$ or $\overline{D}$ particle with the components of a $BD$ cluster, previously proved to form a bound state. We find an $I({J}^{P})=1/2({0}^{\ensuremath{-}})$ bound state for the $BD\overline{D}$ system at an energy around 8925--8985 MeV within uncertainties, which would correspond to a bottom hidden-charm meson. In contrast, for the $BDD$ system, which would be bottom double-charm and hence manifestly exotic, we have found h…
Mechanisms Suppressing Superheavy Element Yields in Cold Fusion Reactions.
2019
Superheavy elements are formed in fusion reactions which are hindered by fast nonequilibrium processes. To quantify these, mass-angle distributions and cross sections have been measured, at beam energies from below-barrier to 25% above, for the reactions of $^{48}\mathrm{Ca}$, $^{50}\mathrm{Ti}$, and $^{54}\mathrm{Cr}$ with $^{208}\mathrm{Pb}$. Moving from $^{48}\mathrm{Ca}$ to $^{54}\mathrm{Cr}$ leads to a drastic fall in the symmetric fission yield, which is reflected in the measured mass-angle distribution by the presence of competing fast nonequilibrium deep inelastic and quasifission processes. These are responsible for reduction of the compound nucleus formation probablity ${P}_{CN}$ …
Modeling of energy transfer from the photon beam at an optical media
2004
Laser beam could be applied to act in optical media, to build different spatial images. The operation could be made direct by copying an image or through a C.D. The successive points could be realized with relatively high speed, like 103-105 points per second. Each point represents practically a machining operation done by the laser beam. In most cases, energy transfer is made not in a plane, but in a volume, and this requires moving the focal point in positions required by the image we want to create. This is a sequentially operation, made point by point following a definite order, but in the same time, because the image is spatially, we have to adapt also other parameters of the optical s…
Quantization as a consequence of the group law
1982
A method of gemetric quantization which solely makes use of the structure of the symmetry group of the dynamical system is proposed; the classical limit is discussed along similar lines. The method is applied to two examples, the free particle and the harmonic oscillator.