Search results for "RETRIEVAL"
showing 10 items of 1176 documents
H2-He vibrational line-shape parameters: Measurement and semiclassical calculation
1995
High-resolution inverse Raman spectroscopy has been used to obtain the line shifting and line broadening coefficients of H{sub 2} perturbed by He. Measurements have been made for the {ital Q}-branch transitions ({ital J}=0{r_arrow}5) in a density range of 10 to 20 amagat and from 296 to 995 K. Up to 795 K we have directly deduced from the experimental broadening coefficients the inelastic rotational state-to-state and vibrational dephasing rates. At higher temperatures, owing to the larger number of channels of relaxation which occur, the results have been analyzed using a scaling law. The line shift and broadening coefficients exhibit a square root and a linear dependence on temperature, r…
Transverse nonlinear optics in heavy-metal-oxide glass
2008
6 pags. ; 9 figs.
Approximate triangle amplitude for three-body charge exchange processes.
1996
The single-rescattering contribution to the amplitude pertaining to three-body charge exchange reactions (triangle amplitude) contains the off-shell Coulomb {ital T}-matrix {ital T}{sup {ital C}} describing the intermediate-state Coulomb scattering of charged subsystems. For ease of computation, the latter is usually replaced by the potential {ital V}{sup {ital C}} which, however, is unsatisfactory in many cases. An alternative approximation, obtained by {open_quote}{open_quote}renormalizing{close_quote}{close_quote} the {open_quote}{open_quote}triangle{close_quote}{close_quote} contribution with {ital V}{sup {ital C}} instead of {ital T}{sup {ital C}} by a simple analytic expression, is sh…
Scattering from finite-volume energies including higher partial waves and multiple decay channels
2018
A new implementation of estimating the two-to-two $K$-matrix from finite-volume energies based on the Luescher formalism is described. The method includes higher partial waves and multiple decay channels, and the fitting procedure properly includes all covariances and statistical uncertainties. The method is also simpler than previously used procedures. Formulas and software for handling total spins up to $S=2$ and orbital angular momenta up to $L=6$ are presented.
Phase retrieval of a Kolmogorov phase screen from very sparse data using four binary masks
2020
We investigate experimentally the phase retrieval of a Kolmogorov phase screen from very sparse data by modulating its amplitude with four binary masks and compare the retrieved phase screen to the ground truth measured with a surface profiler. Previously, we have shown in simulations that this kind of modulation can be successfully used for the phase retrieval of a Kolmogorov phase screen. After subtracting the ground truth from the retrieved phase screen, the root-mean-square error decreased from 0.14 µm to 0.10 µm. We conclude that a Kolmogorov phase screen can be recovered using simple modulation and very sparse data.
Extensions, expansions, Lie algebra cohomology and enlarged superspaces
2004
After briefly reviewing the methods that allow us to derive consistently new Lie (super)algebras from given ones, we consider enlarged superspaces and superalgebras, their relevance and some possible applications.
Gauge invariance and unstable particles.
1995
A gauge-independent approach to resonant transition amplitudes with nonconserved external currents is presented, which is implemented by the pinch technique. The analytic expressions derived with this method are $U(1)_{em}$ invariant, independent of the choice of the gauge-fixing parameter, and satisfy a number of required theoretical properties, including unitarity. Although special attention is paid to resonant scatterings involving the $\gamma WW$ and $ZWW$ vertices in the minimal Standard Model, our approach can be extended to the top quark or other unstable particles appearing in renormalizable models of new physics.
Search for new physics using QUAERO: A general interface to D0 Event data
2001
We describe Quaero, a method that i) enables the automatic optimization of searches for physics beyond the standard model, and ii) provides a mechanism for making high energy collider data generally available. We apply Quaero to searches for standard model WW, ZZ, and ttbar production, and to searches for these objects produced through a new heavy resonance. Through this interface, we make three data sets collected by the D0 experiment at sqrt(s)=1.8 TeV publicly available.
Isospin triplet A=14: search for states with enhanced radii
2020
Abstract This article is devoted to study of isobar-analogue states 1− in triplet A=14: 14C-14N-14O. Previously signs of neutron halo in the 1−, 6.09 MeV state of 14C were obtained by two independent groups. In this article we propose to study neighbouring nuclei 14N and 14O using the Modified diffraction model (MDM) method and the method of Asymptotic normalization coefficients (ANC). Methods were applied to experimental differential cross sections of 14C(α,α)14C scattering and reactions 13C(3He,d)14N and 14N(3He,t)14O. MDM and ANC gave practically similar within errors radii for the studied 1− states: the 6.09 MeV state in 14C – 2.7±0.1 fm, the 8.06 MeV state in 14N – 2.7 ± 0.1 fm, the 5.…