scholarly journals Incorporation of Threshold Phenomena in Three-body Coulomb Continuum Wavefunctions

1996 ◽  
Vol 49 (6) ◽  
pp. 1095 ◽  
Author(s):  
Jamal Berakdar
Keyword(s):  
Spin Asymmetry ◽  
Excess Energy ◽  
Absolute Value ◽  
Threshold Phenomena ◽  
Cusp Conditions ◽  
Wannier Threshold ◽  
Coulomb Boundary Conditions ◽  
Three Body ◽  
Energy Sharing ◽  
First Time

In this work a three-body Coulomb wavefunction for the description of two continuum electrons moving in the field of a nucleus is constructed such that the Wannier threshold law for double escape is reproduced and the asymptotic Coulomb boundary conditions as well as the Kato cusp conditions are satisfied. It is shown that the absolute value of the total cross section, as well as the spin asymmetry, are well described by the present approach. Further, the excess-energy sharing between the two escaping electrons is calculated and analysed in light of the Wannier theory predictions. This is the first time an analytical three-body wavefunction is presented which is asymptotically exact and capable of describing threshold phenomena.

Who Did the Audit? Audit Quality and Disclosures of Other Audit Participants in PCAOB Filings

2014 ◽  
Vol 90 (5) ◽  
pp. 1939-1967 ◽  
Author(s):  
Carol Callaway Dee ◽  
Ayalew Lulseged ◽  
Tianming Zhang
Keyword(s):  
Audit Quality ◽  
Market Reaction ◽  
Audit Fees ◽  
Discretionary Accruals ◽  
Multivariate Model ◽  
Significant Decline ◽  
Earnings Response Coefficients ◽  
Absolute Value ◽  
Earnings Response ◽  
First Time

ABSTRACT We empirically test whether audit quality is affected when part of an SEC issuer's audit is outsourced to auditors other than the principal auditor (“participating auditors”). We find a significantly negative market reaction and a significant decline in earnings response coefficients (ERCs) for experimental issuers disclosed for the first time as having participating auditors involved in their audits. However, we find no market reaction and no decline in ERCs for a matching sample of issuers that are not disclosed as using participating auditors, nor for issuers disclosed for the second or third time as using participating auditors. We also find actual audit quality as measured by absolute value of performance-matched discretionary accruals is lower for the experimental issuers, although we find no difference in audit fees paid by the experimental and matching issuers in a multivariate model. Our findings suggest that the PCAOB's proposed rule requiring disclosure of the use of other auditors in addition to the principal auditor would provide information useful to investors in assessing audit quality for SEC issuers.

Detection and Quantification of 7-Hydroxydehydroepiandrosterone Epimers in Three Body Fluids

2002 ◽  
Vol 67 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Richard Hampl ◽  
Martin Hill ◽  
Luboslav Stárka
Keyword(s):  
Healthy Subjects ◽  
Serum Levels ◽  
Body Fluids ◽  
Gas Chromatography Mass Spectrometry ◽  
Specific Radioimmunoassay ◽  
Order Of Magnitude ◽  
Three Body ◽  
First Time ◽  
Nanomolar Range ◽  
Detection And Quantification

3β,7α-Dihydroxyandrost-5-en-17-one (1) (7α-OH-DHEA) and its 7β-hydroxy epimer 2 (7β-OH-DHEA) - 7α- and 7β-hydroxydehydroepiandrosterone - were detected and quantified in three human body fluids: in blood serum, saliva and ejaculate. Specific radioimmunoassay and gas chromatography-mass spectrometry have been used. For the first time the data on changes of these dehydroepiandrosterone metabolites are reported for a representative group of healthy subjects of both sexes (172 females and 217 males) during the life span. The serum levels of both 7-hydroxydehydroepiandrosterone epimers in serum and also in semen were in the low nanomolar range, while concentrations by one order of magnitude lower were found in saliva, but still within the detection limit. The results will serve as a basis for comparative studies of 7-hydroxydehydroepiandrosterone levels under various pathophysiological conditions, with a particular respect to autoimmune disorders.

Note on radiationless transitions involving three-body collisions

1936 ◽  
Vol 32 (3) ◽  
pp. 482-485 ◽  
Author(s):  
R. A. Smith
Keyword(s):  
Continuous Spectrum ◽  
Negative Ions ◽  
Bound State ◽  
Excess Energy ◽  
Negative Ion ◽  
Positive Ions ◽  
Continuous State ◽  
Direct Formation ◽  
Three Body ◽  
Positive Ion

When an electron makes a transition from a continuous state to a bound state, for example in the case of neutralization of a positive ion or formation of a negative ion, its excess energy must be disposed of in some way. It is usually given off as radiation. In the case of neutralization of positive ions the radiation forms the well-known continuous spectrum. No such spectrum due to the direct formation of negative ions has, however, been observed. This process has been fully discussed in a recent paper by Massey and Smith. It is shown that in this case the spectrum would be difficult to observe.

Axial Impact Buckling of a Column With Random Initial Imperfections

1978 ◽  
Vol 45 (2) ◽  
pp. 361-365 ◽  
Author(s):  
I. Elishakoff
Keyword(s):  
Critical Time ◽  
Initial Imperfection ◽  
Random Variable ◽  
Axial Impact ◽  
Absolute Value ◽  
Initial Imperfections ◽  
Total Displacement ◽  
Probabilistic Setting ◽  
Probabilistic Nature ◽  
First Time

Axial impact buckling of perfectly elastic bars with initial imperfections is considered in a probabilistic setting. It is assumed that the initial imperfection function involved a single parameter, which in turn is a continuous random variable with given probability distribution function. The structure is said to buckle if the absolute value of the total displacement exceeds a prescribed value. The probabilistic nature of the random, critical time when such a failure occurs for the first time, is studied.

Resonance, Chaos and Stability in the General Three-Body Problem

2007 ◽  
Vol 3 (S246) ◽  
pp. 199-208 ◽  
Author(s):  
R. A. Mardling
Keyword(s):  
Chaos Theory ◽  
Clusters Of Galaxies ◽  
Three Body Problem ◽  
Orbital Elements ◽  
Resonance Overlap ◽  
Practical Algorithm ◽  
The Stability ◽  
Three Body ◽  
First Time ◽  
Analytical Expressions

AbstractThree-body stability is fundamental to astrophysical processes on all length and mass scales from planetary systems to clusters of galaxies, so it is vital we have a deep and thorough understanding of this centuries-old problem. Here we summarize an analytical method for determining the stability of arbitrary three-body hierarchies which makes use of the chaos theory concept of resonance overlap. For the first time the dependence on all orbital elements and masses can be given explicitly via simple analytical expressions which contain no empirical parameters. For clarity and brevity, analysis in this paper is restricted to coplanar systems including a description of a practical algorithm for use in N-body and other applications. A Fortran routine for arbitrarily inclined systems is available from the author, and animations of stable and unstable systems are available at www.maths.monash.edu.au/~ro/Capri.

Polarizabilities and other properties of the tdµ molecular ion

2001 ◽  
Vol 79 (9) ◽  
pp. 1149-1158
Author(s):  
A K Bhatia ◽  
R J Drachman
Keyword(s):  
Energy Levels ◽  
Molecular Ions ◽  
Muon Catalyzed Fusion ◽  
Oppenheimer Approximation ◽  
Good Energy ◽  
Cusp Conditions ◽  
Fermi Contact ◽  
Muonic System ◽  
Three Body ◽  
Contact Parameters

Wave functions of the Hylleraas type were used earlier to calculate energy levels of muonic systems. Recently, we found in the case of the molecular ions H2+, D2+, and HD+ that it was necessary to include high powers of the internuclear distance in the Hylleraas functions to localize the nuclear motion when treating the ions as three-body systems without invoking the Born–Oppenheimer approximation. We tried the same approach in a muonic system, tdµ– (triton, deuteron, and muon). Improved convergence was obtained for J = 0 and 1 states for shorter expansions when we used this type of generalized Hylleraas function, but as the expansion length increased the high powers were no longer useful. We obtained good energy values for the two lowest J = 0 and 1 states and compared them with the best earlier calculations. Expectation values were obtained for various operators, the Fermi contact parameters, and the permanent quadrupole moment. The cusp conditions were also calculated. The polarizability of the ground state was then calculated using second-order perturbation theory with intermediate J = 1 pseudostates. (It should be possible to measure the polarizability by observing Rydberg states of atoms with tdµ– acting as the nucleus.) In addition, the initial sticking probability (an essential quantity in the analysis of muon catalyzed fusion) was calculated and compared with earlier results. PACS Nos.: 30.00, 36.10-k, 02.70-c

scholarly journals Helium-like ions in d-dimensions: analyticity and generalized ground state Majorana solutions

2021 ◽  
Author(s):  
Adrian Mauricio Escobar ◽  
Horacio Olivares-Pilón ◽  
Norberto Aquino ◽  
Salvador Antonio Cruz-Jimenez
Keyword(s):  
Ground State Energy ◽  
Ground State ◽  
State Energy ◽  
Dimensional Space ◽  
Algebraic Function ◽  
Approximate Solutions ◽  
Algebraic Expression ◽  
Three Body ◽  
First Time ◽  
Analytical Expressions

Abstract Non-relativistic Helium-like ions (−e, −e, Ze) with static nucleus in a d−dimensional space (d > 1) are considered. Assuming r−1Coulomb interactions, a 2-parametric correlated Hylleraas-type trial function is used to calculate the ground state energy of the system in the domain Z ≤ 10. For odd d = 3, 5, the variational energy is given by a rational algebraic function of the variational parameters whilst for even d = 2, 4 it is shown for the first time that it corresponds to a more complicated non-algebraic expression. This twofold analyticity will hold for any d. It allows us to construct reasonably accurate approximate solutions for the ground state energy E0(Z, d) in the form of compact analytical expressions. We call them generalized Majorana solutions. They reproduce the first leading terms in the celebrated 1Z expansion, and serve as generating functions for certain correlation-dependent properties. The (first) critical charge Zc vs d and the Shannon entropy S(d)r vs Z are also calculated within the present variational approach. In the light of these results, for the physically important case d = 3 a more general 3-parametric correlated Hylleraas-type trial is used to compute the finite mass effects in the Majorana solution for a three-body Coulomb system with arbitrary charges and masses. It admits a straightforward generalization to any d as well. Concrete results for the systems e− e− e+, H+2 and H− are indicated explicitly. Our variational analytical results are in excellent agreement with the exact numerical values reported in the literature.

scholarly journals Revisiting the supersymmetric Pati–Salam models from intersecting D6-branes

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Tianjun Li ◽  
Adeel Mansha ◽  
Rui Sun
Keyword(s):  
Model Building ◽  
Gauge Coupling ◽  
Type Ii ◽  
Absolute Value ◽  
Hidden Sector ◽  
Gauge Symmetries ◽  
The Standard Model ◽  
New Models ◽  
Time Construct ◽  
First Time

AbstractEmploying novel random and supervised scanning methods, we systematically revisit the construction of three-family $$N=1$$ N = 1 supersymmetric Pati–Salam models in Type IIA orientifolds on $$\mathbf{T}^6/({\mathbb {Z}}_2\times {\mathbb {Z}}_2)$$ T 6 / ( Z 2 × Z 2 ) with intersecting D6-branes. Arising from the stacks of D6-branes with U(n) gauge symmetries, the Pati–Salam gauge symmetries $$SU(4)_C\times SU(2)_L \times SU(2)_R$$ S U ( 4 ) C × S U ( 2 ) L × S U ( 2 ) R can be broken down to the Standard Model via D-brane splitting as well as D- and F-flatness preserving Higgs mechanism. Also, the hidden sector contains USp(n) branes, which are parallel with the orientifold planes or their $${{\mathbb {Z}}_2}$$ Z 2 images. We find that the Type II T-duality in the previous study is not an equivalent relation in Pati–Salam model building if the model is not invariant under $$SU(2)_L$$ S U ( 2 ) L and $$SU(2)_R$$ S U ( 2 ) R exchange, and provides a way to obtain new models. We systematically construct the new models with three families, which usually do not have gauge coupling unification at the string scale. We for the first time construct the Pati–Salam models with at least one wrapping number whose absolute value reaching 5. In particular, for one large wrapping number equal to 5, we find that one kind of model carries more refined gauge couplings, and thus with more possibilities to have approximate gauge coupling unification.

scholarly journals Two Correlations with Enhancement Near the Proton Gyroradius Scale in Solar Wind Turbulence: Parker Solar Probe (PSP) and Wind Observations

2022 ◽  
Vol 924 (2) ◽  
pp. 92
Author(s):  
G. Q. Zhao ◽  
Y. Lin ◽  
X. Y. Wang ◽  
H. Q. Feng ◽  
D. J. Wu ◽  
...  
Keyword(s):  
Solar Wind ◽  
Magnetic Energy ◽  
Data Sets ◽  
Absolute Value ◽  
Magnetic Energy Density ◽  
Solar Wind Turbulence ◽  
Proton Temperature ◽  
Wind Turbulence ◽  
First Time ◽  
Probe Mission

Abstract Based on the Parker Solar Probe mission, this paper presents the observations of two correlations in solar wind turbulence near the Sun for the first time, demonstrating the clear existence of the following two correlations. One is positive correlation between the proton temperature and turbulent magnetic energy density. The other is negative correlation between the spectral index and magnetic helicity. It is found that the former correlation has a maximum correlation coefficient (CC) at the wavenumber k ρ p ≃ 0.5 (ρ p being the proton thermal gyroradius), and the latter correlation has a maximum absolute value of CC at k ρ p ≃ 1.8. In addition, investigations based on 11 yr of Wind observations reveal that the dimensionless wavenumbers (k ρ p ) corresponding to the maximum (absolute) values of CC remain nearly the same for different data sets. These results tend to suggest that the two correlations enhanced near the proton gyroradius scale would be a common feature of solar wind turbulence.

Broadening and shifting of the Raman Q branch in D2 and D2–He mixtures, II: line shapes, fitting routines, and effects nonlinear in density

1994 ◽  
Vol 72 (11-12) ◽  
pp. 891-896 ◽  
Author(s):  
P. M. Sinclair ◽  
P. Duggan ◽  
J. W. Forsman ◽  
J. R. Drummond ◽  
A. D. May
Keyword(s):  
Molecular Dynamics ◽  
Line Shape ◽  
Preceding Paper ◽  
Binary Collision ◽  
Spectral Profile ◽  
Lorentzian Line ◽  
Line Shapes ◽  
And Shifts ◽  
Three Body ◽  
First Time

In the preceding paper we fitted the experimental profiles using a single Lorentzian line shape and assumed that the width and shift were proportional to the density. Here we discuss nonlinear contributions to widths and shifts and present a different spectral profile and analysis that allows us (i) to determine unbiased, binary collision, impact limit, broadening and shifting coefficients; (ii) to disentangle several effects nonlinear in the density; and, subsequently, (iii) to observe broadening and shifting arising purely from the correlation between perturbers and three-body interactions. This is a new avenue of research in molecular dynamics. In addition, measurements of the broadening of the depolarized part of the Q branch in D2 are reported for the first time.

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