scholarly journals Magnetic field-free measurements of the total cross sections for positron–neon and positron–argon scattering

2012 ◽  
Vol 388 (7) ◽  
pp. 072001
Author(s):  
K Nagumo ◽  
Y Nitta ◽  
M Hoshino ◽  
J P Sullivan ◽  
H Tanaka ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cross Sections ◽  
Total Cross Sections

Elastic Scattering of Positrons in Neon and Argon and Phase Shift Analysis from 4 eV to Inelastic Thresholds

1974 ◽  
Vol 52 (3) ◽  
pp. 272-277 ◽  
Author(s):  
B. Jaduszliwer ◽  
D. A. L. Paul
Keyword(s):  
Magnetic Field ◽  
Elastic Scattering ◽  
Phase Shift ◽  
Cross Sections ◽  
Phase Shift Analysis ◽  
Wave Number ◽  
Total Cross Sections ◽  
Shift Analysis ◽  
Neon Gas ◽  
Scattering Chamber

The transmission of positrons through neon gas has been studied in the elastic region below the positronium formation threshold at energies from 4 eV to 14 eV, and the same experiment was carried out for argon from 4 eV to 8 eV. By repeating the measurements using three values of magnetic field along the scattering chamber, in the direction of transmission, some sensitivity to individual phase shifts is obtained, and a phase shift analysis has been carried out. The l = 0, 1, and 2 shifts are each parametrized as a two term power expansion in the wave number, while the forms of δ3, δ4 are assumed from theory. The results of the analysis are compared with published theories and indicate the need for more accurate calculations, particularly for argon. The total cross sections deduced for neon are in disagreement with the smaller values measured by Canter, Coleman, Griffith, and Heyland, but the cross sections for argon are in agreement with theirs.

scholarly journals Radion Production in External Electromagnetic Field

2011 ◽  
Vol 21 (3) ◽  
pp. 193
Author(s):  
Phung Van Dong ◽  
Hoang Ngoc Long ◽  
Nguyen Huy Thao ◽  
Dang Van Soa ◽  
Nguyen Thi Hau
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Laboratory Experiment ◽  
Cross Sections ◽  
External Electromagnetic Field ◽  
Total Cross Sections ◽  
The Magnetic Field

A review of Randall-Sundrum model with stressing on radion phenomenology is presented. The radion production in the external electromagnetic field is considered. The total cross sections for the conversions in the presence of the electric field of the flat condenser as well as in the magnetic field of the solenoid are calculated in details. Based on our results a laboratory experiment for production and detection of the light radions may be described.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

Positronium- and positron–H2O total cross sections

2006 ◽  
Vol 39 (6) ◽  
pp. 1337-1344 ◽  
Author(s):  
J Beale ◽  
S Armitage ◽  
G Laricchia
Keyword(s):  
Cross Sections ◽  
Total Cross Sections

Justification of a Simple Ramsauer Model for Neutron Total Cross Sections

1998 ◽  
Vol 130 (3) ◽  
pp. 340-347 ◽  
Author(s):  
S. M. Grimes ◽  
J. D. Anderson ◽  
R. W. Bauer ◽  
V. A. Madsen
Keyword(s):  
Cross Sections ◽  
Total Cross Sections
Sign in / Sign up

Export Citation Format

Share Document