Charge and state population in dilute plasmas from beam-foil spectroscopy

2008 ◽  
Vol 86 (2) ◽  
pp. 331-350 ◽  
Author(s):  
C T Chantler
Keyword(s):  
Radiative Decay ◽  
Precision Measurements ◽  
Spectral Emission ◽  
State Evolution ◽  
Relativistic Regime ◽  
Foil Target ◽  
First Time ◽  
Production Mechanisms ◽  
Theoretical Results ◽  
Beam Foil

Beam-foil spectroscopy has a long history for determining charge state evolution, radiative decay lifetimes, spectral widths, and satellite structure. Many theoretical results predict a range of populations and state dependencies, but high resolution or a very large bandpass is normally required to test or investigate these. The current investigation has tested some key assumptions and models as applied to this relativistic regime, particularly for few-electron iron resonances and satellites. We conclude that there are two specific production mechanisms, one inside the target to low-n levels and one dominated by capture mechanisms at the exit of the foil, with particularly significant Rydberg cascades. Several systematics in high-precision measurements of these systems are discussed and quantified for the first time. The 2s–1s and 4f–2p satellites are explicitly investigated, and a dominant systematic is uncovered that is due to the variable location of spectral emission, downstream of the beam-foil target. PACS Nos.: 32.70.Jz, 34.10.+x, 52.20.Hv, 34.60.+z

scholarly journals b→sγ AND ε1 CONSTRAINTS ON SUPERGRAVITY MODELS

1996 ◽  
Vol 11 (23) ◽  
pp. 1877-1885 ◽  
Author(s):  
GYE T. PARK
Keyword(s):  
Supergravity Models ◽  
Top Quark ◽  
Radiative Decay ◽  
Previous Analysis ◽  
Precision Measurements ◽  
Scale Model ◽  
Quark Masses ◽  
Flavor Changing ◽  
The One ◽  
First Time

In the light of the top quark discovered very recently by CDF, we investigate the possibility of narrowing down the allowed top quark masses by combining for the first time only two strongest constraints present in the no-scale SU (5)× U (1) supergravity model, namely, the ones from the flavor-changing radiative decay b→sγ and the precision measurements at LEP in the form of ε1. It turns out that even without including the most devastating constraint from [Formula: see text] measurement at LEP in the form of Rb directly or εb indirectly, the combined constraint from b→sγ and ε1 alone in fact excludes mt(mt)≳180 GeV altogether in the no-scale model, providing a constraint on mt near the upper end of the CDF values. The resulting upper bound on mt is stronger and 5 GeV lower than the one from combining ε1 and εb constraints and also combining b→sγ and εb constraints in the previous analysis.

Remarks about factors shaping the heliosphere

2018 ◽  
Vol 92 (3) ◽  
pp. 329-335
Author(s):  
Romana Ratkiewicz ◽  
Wojciech Konior ◽  
Jan Kotlarz
Keyword(s):  
Status Report ◽  
Physical Processes ◽  
Content Type ◽  
General Review ◽  
New Information ◽  
Conceptual Paper ◽  
First Time ◽  
Practical Implications ◽  
Theoretical Results

Purpose The purpose of the paper is to give a brief description of the new topic introduced for the first time at the EASN Conferences. Design/methodology/approach The topic concerns the heliosphere, the nearest surrounding of the Sun and thus the nearest vicinity of the Earth. The heliosphere is created due to the interaction between the solar wind and the local interstellar medium. Findings This paper does not include any new information about the heliosphere and only introduces a new topic to this journal. It is briefly shown how heliospheric structures are formed, what factors affect a shape of the heliosphere, what measurements are made by Ulysses, Voyager and IBEX space missions (important for the heliosphere modeling) and how obtained data are used to validate theoretical results. Practical implications To categorize the paper under one of these classifications, research paper, viewpoint, technical paper, conceptual paper, case study, literature review or general review, the authors chose a paper type, general review, as the closest category to this paper. However, it is not a purpose of this paper to provide an extensive review of the community efforts to investigate the physical processes in the vicinity of the heliosphere interface. This is mostly a status report. Originality/value As the new topic in this journal, the article introduces in detail only a small number of aspects connected with heliosphere models. Interplanetary and interstellar magnetic field structures are primarily described. Other factors are only mentioned.

Determination of hyperon properties through the variational method considering the hyperfine interaction

2019 ◽  
Vol 28 (10) ◽  
pp. 1950087 ◽  
Author(s):  
S. M. Moosavi Nejad ◽  
A. Armat
Keyword(s):  
Experimental Data ◽  
Wave Function ◽  
Ground State ◽  
Radiative Decay ◽  
Magnetic Moments ◽  
Wave Functions ◽  
Decay Widths ◽  
Free Parameters ◽  
Theoretical Results

Performing a fit procedure on the hyperon masses, we first determine the free parameters in the Cornell-like hypercentral potential between the constituent quarks of hyperons in their ground state. To this end, using the variational principle, we apply the hyperspherical Hamiltonian including the Cornell-like hypercentral potential and the perturbation potentials due to the spin–spin, spin–isospin and isospin–isospin interactions between constituent quarks. In the following, we compute the hyperon magnetic moments as well as radiative decay widths of spin-3/2 hyperons using the spin-flavor wave function of hyperons. Our analysis shows acceptable consistencies between theoretical results and available experimental data. This leads to reliable wave functions for hyperons at their ground state.

scholarly journals Generalized Inverses Estimations by Means of Iterative Methods with Memory

Mathematics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 2
Author(s):  
Santiago Artidiello ◽  
Alicia Cordero ◽  
Juan R. Torregrosa ◽  
María P. Vassileva
Keyword(s):  
Iterative Methods ◽  
Generalized Inverses ◽  
Drazin Inverse ◽  
Nonsingular Matrix ◽  
Type Method ◽  
The Matrix ◽  
Nonlinear Matrix ◽  
First Time ◽  
With Memory ◽  
Theoretical Results

A secant-type method is designed for approximating the inverse and some generalized inverses of a complex matrix A. For a nonsingular matrix, the proposed method gives us an approximation of the inverse and, when the matrix is singular, an approximation of the Moore–Penrose inverse and Drazin inverse are obtained. The convergence and the order of convergence is presented in each case. Some numerical tests allowed us to confirm the theoretical results and to compare the performance of our method with other known ones. With these results, the iterative methods with memory appear for the first time for estimating the solution of a nonlinear matrix equations.

scholarly journals Big Bang Bifurcations in the Tantalus Oscillator Under Biphasic Perturbations

2019 ◽  
Vol 29 (02) ◽  
pp. 1950023
Author(s):  
Humberto Arce ◽  
Araceli Torres ◽  
Augusto Cabrera ◽  
Martín Alarcón ◽  
Carlos Málaga
Keyword(s):  
Bifurcation Diagram ◽  
Limit Cycle ◽  
Excellent Agreement ◽  
Big Bang ◽  
Wide Range ◽  
Coupling Time ◽  
First Time ◽  
Hydrodynamic Oscillator ◽  
Range Of Values ◽  
Theoretical Results

The Tantalus Oscillator is a nonlinear hydrodynamic oscillator with an attractive limit cycle. In this study, we pursue the construction of a biparametric bifurcation diagram for the Tantalus Oscillator under biphasic perturbations. That is the first time that this kind of diagram is built for this kind of oscillator under biphasic perturbations. Results show that biphasic perturbations have no effect when the coupling time is chosen over a wide range of values. This modifies the bifurcation diagram obtained under monophasic perturbations. Now we have the appearance of periodic increment Big Bang Bifurcations. The theoretical results are in excellent agreement with experimental observations.

An Experimental Study of Torsional Vibration Absorbers

2001 ◽  
Author(s):  
Alan G. Haddow ◽  
Steven W. Shaw
Keyword(s):  
Experimental Study ◽  
Dynamic Behavior ◽  
Systematic Study ◽  
Torsional Vibration ◽  
Theoretical Background ◽  
Controlled Environment ◽  
Vibration Absorbers ◽  
Test Apparatus ◽  
First Time ◽  
Theoretical Results

Abstract This paper presents results from tests completed on a rotor system fitted with pendulum-type torsional vibration absorbers. A review of the associated theoretical background is also given and the experimental and theoretical results are compared and contrasted. An overview of the test apparatus is provided and its unique features are discussed. To the best knowledge of the authors, this is the first time that a systematic study of the dynamic behavior of torsional vibration absorbers has been undertaken in a controlled environment.

Tsallis-Statistical Approach to the Specific Heat of LIQUID 4HE: Comparison with Other Results

1997 ◽  
Vol 11 (19) ◽  
pp. 2303-2310 ◽  
Author(s):  
Sergio Curilef ◽  
Andrés R. R. Papa
Keyword(s):  
Experimental Data ◽  
Comparative Analysis ◽  
Quantum Group ◽  
Specific Heat ◽  
High Precision ◽  
Theoretical Approach ◽  
Statistical Approach ◽  
Precision Measurements ◽  
Best Fitting ◽  
Theoretical Results

A theoretical approach within a quantum-group formalism has recently been proposed and successfully compared to Greywall's high precision measurements of the liquid 4 He specific heat. We calculate here the specific heat for 4 He using Tsallis' non-extensive thermostatistics. A comparative analysis reveals that there is a temperature range where our theoretical results yield the best fitting to experimental data.

DETECTION OF RELIC NEUTRINOS FROM THE DECAY OF FOURTH GENERATION NEUTRINOS USING THE NEUTRINO WINDOW ON THE EARTH

1993 ◽  
Vol 08 (16) ◽  
pp. 1461-1468
Author(s):  
WOO-PYO HONG ◽  
DAVID B. CLINE ◽  
YOUNG-DAE JUNG
Keyword(s):  
Decay Width ◽  
Early Universe ◽  
Radiative Decay ◽  
Detection Method ◽  
Neutrino Flux ◽  
Precision Measurements ◽  
Fourth Generation ◽  
The Earth

The recent precision measurements of Z0 decay width of LEP/SLC results may allow the existence of a heavy fourth generation neutrino with mass mν4 above ~45 GeV. The fourth generation neutrinos, by non-radiative decay in the early Universe, may yield a detectable diffuse relic neutrinos (νμ and ντ) on the earth with energies around 10–100 MeV. We discuss a possible detection method of the diffuse relic flux. This relic diffuse neutrino flux, if observed, would strongly support the existence of the fourth generation neutrinos.

A Theoretical Investigation of the Jet-Flap Compressor Cascade in Incompressible Flow

1972 ◽  
Vol 94 (4) ◽  
pp. 249-260
Author(s):  
U. Stark
Keyword(s):  
Incompressible Flow ◽  
Time Pressure ◽  
Inviscid Flow ◽  
Compressor Cascade ◽  
Pressure Distributions ◽  
Simplifying Assumptions ◽  
Stagger Angle ◽  
First Time ◽  
Theoretical Results ◽  
Insight Into

The use of jet flaps gives a new possibility of achieving high turning cascades. In this paper a new theory for unstaggered cascades with jet flaps, developed under simplifying assumptions, is described. With the help of this theory, besides turning angles and lift coefficients, for the first time pressure distributions on, and jet slope distributions behind, the blades were calculated. The effect of stagger angle on the turning angles and lift coefficients is determined with the help of the Schlichting method, using the concept of the equivalent flat plate cascade. Sample calculations illustrate the theory and, at the same time, give an insight into the behavior of cascades with jet flaps in inviscid flow. Results of previously published experiments on cascades with jet flaps, where they fulfill the conditions of the theory, are compared with the theoretical results and demonstrate satisfactory agreement.

Beam–foil spectroscopy of sulfur in the vacuum ultraviolet

1976 ◽  
Vol 54 (7) ◽  
pp. 805-815 ◽  
Author(s):  
D. J. G. Irwin ◽  
A. E. Livingston
Keyword(s):  
Time Resolution ◽  
Vacuum Ultraviolet ◽  
Previous Experiment ◽  
Isoelectronic Sequence ◽  
Resolution Capability ◽  
The Mean ◽  
First Time ◽  
Absorption Oscillator Strength ◽  
Beam Foil

We report mean-life results for 16 terms in S III–S VI, obtained from vacuum ultraviolet transitions in sulfur excited by beam–foil interaction. Ten of the mean lives have been measured for the first time. Many of the mean lives reported here are in the neighborhood of 0.1 ns, beyond the time resolution capability of a previous experiment, as indicated by comparison of results for five of the remaining six terms. For those transitions that are unbranched. we have computed the absorption oscillator strength and we discuss the values in the context of isoelectronic-sequence trends. In an appendix, we discuss the determination of short mean lives and describe the apparatus we have developed to measure them, and its limitations.

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