scholarly journals Pion helicity structure and its consequences for the hard scattering form factor

1996 ◽  
Vol 54 (9) ◽  
pp. 5890-5893 ◽  
Author(s):  
S. W. Wang ◽  
L. S. Kisslinger
Keyword(s):  
Form Factor ◽  
Hard Scattering ◽  
Helicity Structure

scholarly journals Hard scattering amplitude for the higher helicity components of the pion form factor

1997 ◽  
Vol 55 (11) ◽  
pp. 7107-7113 ◽  
Author(s):  
Fu-Guang Cao ◽  
Jun Cao ◽  
Tao Huang ◽  
Bo-Qiang Ma
Keyword(s):  
Form Factor ◽  
Scattering Amplitude ◽  
Pion Form Factor ◽  
Hard Scattering

Hard Scattering Formalism

2018 ◽  
Author(s):  
John Campbell ◽  
Joey Huston ◽  
Frank Krauss
Keyword(s):  
Form Factor ◽  
Cross Sections ◽  
W Boson ◽  
Production Cross ◽  
Distribution Functions ◽  
Hard Scattering ◽  
Parton Distribution Functions ◽  
Sudakov Form Factor ◽  
State Radiation ◽  
Characteristic Features

The hard scattering formalism is introduced, starting from a physical picture based on the idea of equivalent quanta borrowed from QED, and the notion of characteristic times. Contact to the standard QCD treatment is made after discussing the running coupling and the Altarelli–Parisi equations for the evolution of parton distribution functions, both for QED and QCD. This allows a development of a space-time picture for hard interactions in hadron collisions, integrating hard production cross sections, initial and final state radiation, hadronization, and multiple parton scattering. The production of a W boson at leading and next-to leading order in QCD is used to exemplify characteristic features of fixed-order perturbation theory, and the results are used for some first phenomenological considerations. After that, the analytic resummation of the W boson transverse momentum is introduced, giving rise to the notion of a Sudakov form factor. The probabilistic interpretation of the Sudakov form factor is used to discuss patterns in jet production in electron-positron annihilation.

CALCULATION OF SCALAR FORM FACTORS OF NONTOPOLOGICAL SOLITONS

1990 ◽  
Vol 05 (08) ◽  
pp. 1509-1527
Author(s):  
L.S. CELENZA ◽  
A. PANTZIRIS ◽  
C.M. SHAKIN
Keyword(s):  
Wave Function ◽  
Form Factor ◽  
Perturbative Qcd ◽  
Soft Part ◽  
Form Factors ◽  
Bound State ◽  
Mass Scale ◽  
Hard Scattering ◽  
Scalar Form ◽  
The Individual

We study a “toy” model which describes the bound state of two scalar particles. We parameterize the “soft” part of the wave function of the bound state using results obtained in the study of a nontopological soliton model. (This part of the wave function has predominantly lowmomentum components.) We improve this wave function by considering a single “hard” scattering, which we treat in perturbation theory. Thus, we have a model in which the wave function has both “soft” and “hard” parts, in the language used when performing perturbative QCD studies. (The relation of these results to those obtained for electromagnetic form factors in perturbative QCD studies requires further analysis.) We find that the form factor calculated using the “soft” part of the wave function behaves as F(Q2)=F(0)/(1+λ2Q2), where Q2=−q2>0. The individual hard scattering terms yield form factors which have the same form, except for a change of the scale factor, λ. We discuss the approach to the asymptotic form, F(Q2)~Q−2, for the various amplitudes which are summed to obtain the complete form factor. We also discuss the modification of the form factor under a change in mass scale. This modification is relatively simple to study since, in our model, there is only a single dimensionful parameter, κ, which sets the scale for all other dimensional parameters.

The effect of temperature on high-resolution TEM image contrast

1995 ◽  
Vol 53 ◽  
pp. 640-641
Author(s):  
T. Geipel ◽  
W. Mader ◽  
P. Pirouz
Keyword(s):  
Form Factor ◽  
Inelastic Scattering ◽  
Accurate Method ◽  
Waller Factor ◽  
Effect Of Temperature ◽  
Specimen Thickness ◽  
Influence Of Temperature ◽  
Debye Waller Factor ◽  
Influence Of Temperature On ◽  
Atomic Form Factor

Temperature affects both elastic and inelastic scattering of electrons in a crystal. The Debye-Waller factor, B, describes the influence of temperature on the elastic scattering of electrons, whereas the imaginary part of the (complex) atomic form factor, fc = fr + ifi, describes the influence of temperature on the inelastic scattering of electrons (i.e. absorption). In HRTEM simulations, two possible ways to include absorption are: (i) an approximate method in which absorption is described by a phenomenological constant, μ, i.e. fi; - μfr, with the real part of the atomic form factor, fr, obtained from Hartree-Fock calculations, (ii) a more accurate method in which the absorptive components, fi of the atomic form factor are explicitly calculated. In this contribution, the inclusion of both the Debye-Waller factor and absorption on HRTEM images of a (Oll)-oriented GaAs crystal are presented (using the EMS software.Fig. 1 shows the the amplitudes and phases of the dominant 111 beams as a function of the specimen thickness, t, for the cases when μ = 0 (i.e. no absorption, solid line) and μ = 0.1 (with absorption, dashed line).

MAGNETIC FORM FACTOR MEASUREMENTS IN CERIUM HEXABORIDE

1982 ◽  
Vol 43 (C7) ◽  
pp. C7-273-C7-278 ◽  
Author(s):  
P. Burlet ◽  
J. X. Boucherle ◽  
J. Rossat-Mignod ◽  
J. W. Cable ◽  
W. C. Koehler ◽  
...  
Keyword(s):  
Form Factor ◽  
Magnetic Form Factor

FORM FACTOR MEASUREMENTS IN CeTe

1982 ◽  
Vol 43 (C7) ◽  
pp. C7-263-C7-271 ◽  
Author(s):  
J. X. Boucherle ◽  
D. Ravot ◽  
J. Schweizer
Keyword(s):  
Form Factor

FORM FACTOR MEASUREMENT IN FERROMAGNETIC COBALT ORTHOVANADATE

1982 ◽  
Vol 43 (C7) ◽  
pp. C7-253-C7-256
Author(s):  
H. Fuess ◽  
R. Müller ◽  
D. Schwabe ◽  
F. Tasset
Keyword(s):  
Form Factor ◽  
Factor Measurement ◽  
Ferromagnetic Cobalt

Super-Conducting Quantum Interference Device Technique: 3-D Localization of a Short within a Flip Chip Assembly

2001 ◽  
Author(s):  
Kendall Scott Wills ◽  
Omar Diaz de Leon ◽  
Kartik Ramanujachar ◽  
Charles P. Todd
Keyword(s):  
Form Factor ◽  
Failure Analysis ◽  
Time Domain ◽  
Quantum Interference ◽  
Flip Chip ◽  
Time Domain Reflectometry ◽  
Interfacial Region ◽  
Precise Localization ◽  
Super Conducting ◽  
Accuracy Of Measurement

Abstract In the current generations of devices the die and its package are closely integrated to achieve desired performance and form factor. As a result, localization of continuity failures to either the die or the package is a challenging step in failure analysis of such devices. Time Domain Reflectometry [1] (TDR) is used to localize continuity failures. However the accuracy of measurement with TDR is inadequate for effective localization of the failsite. Additionally, this technique does not provide direct 3-Dimenstional information about the location of the defect. Super-conducting Quantum Interference Device (SQUID) Microscope is useful in localizing shorts in packages [2]. SQUID microscope can localize defects to within 5um in the X and Y directions and 35um in the Z direction. This accuracy is valuable in precise localization of the failsite within the die, package or the interfacial region in flipchip assemblies.

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