The determination of band masses and deformation potentials in white tin from an orthogonalized plane wave pseudopotential model

1980 ◽  
Vol 58 (7) ◽  
pp. 1040-1045 ◽  
Author(s):  
D. K. Mak
Keyword(s):  
Form Factor ◽  
Plane Wave ◽  
Fermi Surface ◽  
Energy Dependence ◽  
Form Factors

A method for calculating band masses, using an orthogonalized plane wave (OPW) formalism and taking into account the energy dependence of the pseudopotential form factors, is derived. This is applied to white tin; the results prove to be sensitive only to the energy dependence of the lowest form factor. Deformation potentials for various orbits have been calculated; they are found to be quite anisotropic over the Fermi surface.

scholarly journals U(1) symmetry resolved entanglement in free 1+1 dimensional field theories via form factor bootstrap

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Dávid X. Horváth ◽  
Luca Capizzi ◽  
Pasquale Calabrese
Keyword(s):  
Form Factor ◽  
Branch Point ◽  
Complete Solution ◽  
Form Factors ◽  
Vacuum Expectation ◽  
Field Theories ◽  
The Novel ◽  
Bootstrap Approach ◽  
Twist Fields

Abstract We generalise the form factor bootstrap approach to integrable field theories with U(1) symmetry to derive matrix elements of composite branch-point twist fields associated with symmetry resolved entanglement entropies. The bootstrap equations are solved for the free massive Dirac and complex boson theories, which are the simplest theories with U(1) symmetry. We present the exact and complete solution for the bootstrap, including vacuum expectation values and form factors involving any type and arbitrarily number of particles. The non-trivial solutions are carefully cross-checked by performing various limits and by the application of the ∆-theorem. An alternative and compact determination of the novel form factors is also presented. Based on the form factors of the U(1) composite branch-point twist fields, we re-derive earlier results showing entanglement equipartition for an interval in the ground state of the two models.

Automated Determination of Spur Gear Form Factors

1999 ◽  
Author(s):  
Thomas M. Overman ◽  
Terry E. Shoup
Keyword(s):  
Form Factor ◽  
Form Factors ◽  
Spur Gear ◽  
Spur Gears ◽  
Not Given ◽  
Microsoft Excel ◽  
Gear Teeth ◽  
Automated Determination

Abstract This paper presents a method for determining the form factor (J) and other form factors, which eliminates the need for manual table lookups to AGMA 908-B89 when designing spur gears. It provides an implementation of the algorithms presented in that earlier paper, in an easy-to-use spreadsheet module in Microsoft Excel 97. The implementation also allows form factor calculation for gear teeth combinations not given in the tables of 908-B89, thus eliminating the work of interpolating or extrapolating the tables in that earlier paper.

scholarly journals DISPERSION THEORY METHODS FOR TRANSITION FORM FACTORS

2014 ◽  
Vol 35 ◽  
pp. 1460461
Author(s):  
SEBASTIAN P. SCHNEIDER
Keyword(s):  
Form Factor ◽  
Form Factors ◽  
Transition Form ◽  
Dispersion Theory ◽  
Stepping Stones ◽  
Independent Determination ◽  
Model Independent ◽  
Scattering Contribution ◽  
Theoretical Analyses

Dispersion-theoretical analyses of transition form factors are stepping stones to a model-independent determination of the light-by-light scattering contribution to (g - 2)μ. We extend a calculation of the conversion decays of the lightest isoscalar vector mesons, ω/ϕ → π0ℓ+ℓ-, that builds on a previous dispersive analysis of the ω/ϕ → 3π partial-wave amplitudes and the pion vector form factor as its sole ingredients. We construct a good parametrization of e+e- → 3π that, together with information on the anomalous process γπ → ππ, allows us to obtain a description of the π0 transition form factor measured in e+e- → π0γ.

scholarly journals Verification and Validation of CFD Based Form Factors as a Combined CFD/EFD Method

2021 ◽  
Vol 9 (1) ◽  
pp. 75
Author(s):  
Kadir Burak Korkmaz ◽  
Sofia Werner ◽  
Rickard Bensow
Keyword(s):  
Form Factor ◽  
Best Practice ◽  
Prediction Method ◽  
Form Factors ◽  
Full Scale ◽  
Verification And Validation ◽  
Determination Method ◽  
Power Prediction ◽  
Quality Assurance Procedure

Predicting the propulsive power of ships with high accuracy still remains a challenge. Well established practices in the 1978 ITTC Power Prediction method have been questioned such as the form factor approach and its determination method. This paper investigates the possibility to improve the power predictions by the introduction of a combined CFD/EFD Method where the experimental determination of form factor is replaced by double body RANS computations. Following the Quality Assurance Procedure proposed by ITTC, a best practice guideline has been derived for the CFD based form factor determination method by applying systematic variations to the CFD set-ups. Following the verification and validation of the CFD based form factor method in model scale, the full scale speed-power-rpm relations between large number of speed trials and full scale predictions using the CFD based form factors in combination with ITTC-57 line and numerical friction lines are investigated. It is observed that the usage of CFD based form factors improves the predictions in general and no deterioration is noted within the limits of this study. Therefore, the combination of EFD and CFD is expected to provide immediate improvements to the 1978 ITTC Performance Prediction Method.

scholarly journals Quantum Gases of Dipoles, Quadrupoles and Octupoles in Gross–Pitaevskii Formalism with Form Factor

2020 ◽  
Vol 5 (4) ◽  
pp. 61
Author(s):  
Artem A. Alexandrov ◽  
Alina U. Badamshina ◽  
Stanislav L. Ogarkov
Keyword(s):  
Form Factor ◽  
Gaussian Approximation ◽  
Form Factors ◽  
Quantum Gases ◽  
Hydrodynamic Theory ◽  
Bose Gases ◽  
Probe Wave ◽  
Quantum Hydrodynamic ◽  
Bogoliubov Excitations

Here, classical and quantum field theory of dipolar, axisymmetric quadrupolar and octupolar Bose gases is considered within a general approach. Dipole, axisymmetric quadrupole and octupole interaction potentials in the momentum representation are calculated. These results clearly demonstrate attraction and repulsion areas in corresponding gases. Then the Gross–Pitaevskii (GP) equation, which plays a key role in the present paper, is derived from the corresponding functional. The zoology of the form factors appearing in the GP equation is studied in details. The proper classes for the description of spatially non-uniform condensates form factors are chosen. In the Thomas–Fermi approximation a general solution of the GP equation with a quasilocal form factor is obtained. This solution has an interesting form in terms of a double rapidly converging series that universally includes all the interactions considered. Plots of condensate density functions for the exponential-trigonometric form factor are given. For the sake of completeness, in this paper we consider the GP equation with an optical lattice potential in the limit of small condensate densities. This limit does not distinguish between dipolar, quadrupolar and octupolar gases. An important analysis of the condensate stability, in other words the study of condensate excitations, is also performed in this paper. In the Gaussian approximation (from the Gross–Pitaevskii functional), a functional describing the perturbations of the condensate is derived in detail. This problem is an analog of the Bogolubov transformation used in the study of quantum Bose gases in operator formalism. For a probe wave function in the form of a plane wave, a spectrum of (Bogoliubov) excitations was obtained, from which an equation describing the threshold momentum for the emergence of instability was derived. An important result of this paper is the dependence of the threshold on the momentum of a stationary condensate. For completeness of the presentation, the approximating expression in the form of a rapidly converging series is obtained for the corresponding dependence, and plots of the corresponding series for the exponential-trigonometric form factor are given. Finally, in the conclusion a quantum hydrodynamic theory for dipolar, axisymmetric quadrupolar and octupolar gases is briefly presented, giving a clue to the experimental determination of the form factors.

scholarly journals Bs → Kℓv form factors with 2+1 flavors

2018 ◽  
Vol 175 ◽  
pp. 13008 ◽  
Author(s):  
Yuzhi Liu ◽  
Jon A. Bailey ◽  
A. Bazavov ◽  
C. Bernard ◽  
C. M. Bouchard ◽  
...  
Keyword(s):  
Quark Mass ◽  
Strange Quark ◽  
Lattice Spacing ◽  
Light Quark ◽  
Form Factors ◽  
Ckm Matrix ◽  
Strange Quark Mass ◽  
Light Quark Mass ◽  
B Quark

Using the MILC 2+1 flavor asqtad quark action ensembles, we are calculating the form factors f0 and f+ for the semileptonic Bs → Kℓv decay. A total of six ensembles with lattice spacing from ≈ 0.12 to 0.06 fm are being used. At the coarsest and finest lattice spacings, the light quark mass m’l is one-tenth the strange quark mass m’s. At the intermediate lattice spacing, the ratio m’l/m’s ranges from 0.05 to 0.2. The valence b quark is treated using the Sheikholeslami-Wohlert Wilson-clover action with the Fermilab interpretation. The other valence quarks use the asqtad action. When combined with (future) measurements from the LHCb and Belle II experiments, these calculations will provide an alternate determination of the CKM matrix element |Vub|.

The influence of the nuclear and atomic form factors on the muon bremsstrahlung cross section

1968 ◽  
Vol 46 (10) ◽  
pp. S377-S380 ◽  
Author(s):  
A. A. Petrukhin ◽  
V. V. Shestakov
Keyword(s):  
Form Factor ◽  
Cross Section ◽  
Born Approximation ◽  
Form Factors ◽  
Experimental Results ◽  
Simple Analytical Expression ◽  
Nuclear Form Factor ◽  
The Cross ◽  
Atomic Electrons ◽  
Bremsstrahlung Process

The cross section for the muon bremsstrahlung process is calculated as a function of the nuclear form factor in the Born approximation following the Bethe and Heitler theory. The influence of the nuclear form factor is greater than that taken by Christy and Kusaka. The simple analytical expression for the effect of the screening of the atomic electrons is found. The influence of a decrease in the cross section upon the interpretation of some experimental results is estimated.

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