Relativistic effects in the photoionization of hydrogenic ions

1983 ◽  
Vol 61 (2) ◽  
pp. 198-204 ◽  
Author(s):  
S. P. Goldman ◽  
G. W. F. Drake
Keyword(s):  
Cross Sections ◽  
Energy Region ◽  
Neutral Hydrogen ◽  
Relativistic Effects ◽  
High Energy ◽  
Basis Set ◽  
High Energy Region ◽  
High Energies ◽  
Hydrogenic Ions ◽  
Good Agreement

Accurate relativistic calculations of the oscillator strength densities and photoeffect cross sections for neutral hydrogen and hydrogenic lead (Z = 82) are performed up to the high energy region. Relativistically induced Cooper minima are found in the partial wave contributions at high energies. The results are in good agreement with calculations in which the scattering continuum is represented by a discrete relativistic variational basis set.

The K -shell ionization of atoms by high-energy electrons

1958 ◽  
Vol 247 (1251) ◽  
pp. 550-556 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Born Approximation ◽  
Marked Improvement ◽  
Relativistic Effects ◽  
High Energy ◽  
High Energies ◽  
High Energy Electrons ◽  
Shell Ionization ◽  
Good Agreement

An expression for the cross-section for K -shell ionization of atoms by electrons is obtained by using Moller’s relativistic modification of the Born approximation. Results are presented for the elements with atomic numbers less than 30. For nickel the calculated cross-sections are in good agreement with those measured by Kirkpatrick and his collaborators, a marked improvement due to the allowance for relativistic effects being found at high energies of impact. The normalization of the wave function of the ejected electron is discussed in the appendix.

scholarly journals A lower bound for elastic cross-sections in the high-energy region

1963 ◽  
Vol 29 (5) ◽  
pp. 993-996 ◽  
Author(s):  
A. Martin
Keyword(s):  
Lower Bound ◽  
Cross Sections ◽  
Energy Region ◽  
High Energy ◽  
High Energy Region

scholarly journals Analysis of Shielding Performance of Radiation-Shielding Materials According to Particle Size and Clustering Effects

2021 ◽  
Vol 11 (9) ◽  
pp. 4010
Author(s):  
Seon-Chil Kim
Keyword(s):  
Particle Size ◽  
Polymer Material ◽  
Energy Region ◽  
High Energy ◽  
Radiation Shielding ◽  
High Energy Region ◽  
Particle Structure ◽  
Effect Of Particle Size ◽  
Extensive Body ◽  
Shielding Material

In the field of medical radiation shielding, there is an extensive body of research on process technologies for ecofriendly shielding materials that could replace lead. In particular, the particle size and arrangement of the shielding material when blended with a polymer material affect shielding performance. In this study, we observed how the particle size of the shielding material affects shielding performance. Performance and particle structure were observed for every shielding sheet, which were fabricated by mixing microparticles and nanoparticles with a polymer material using the same process. We observed that the smaller the particle size was, the higher both the clustering and shielding effects in the high-energy region. Thus, shielding performance can be improved. In the low-dose region, the effect of particle size on shielding performance was insignificant. Moreover, the shielding sheet in which nanoparticles and microsized particles were mixed showed similar performance to that of the shielding sheet containing only microsized particles. Findings indicate that, when fabricating a shielding sheet using a polymer material, the smaller the particles in the high-energy region are, the better the shielding performance is. However, in the low-energy region, the effect of the particles is insignificant.

scholarly journals π--PInteraction in High Energy Region

1957 ◽  
Vol 18 (3) ◽  
pp. 264-268 ◽  
Author(s):  
Daisuke Ito ◽  
Tetsuro Kobayashi ◽  
Miwae Yamazaki ◽  
Shigeo Minami
Keyword(s):  
Energy Region ◽  
High Energy ◽  
High Energy Region

3.3.6.4 The high-energy region

2005 ◽  
pp. 306-309
Author(s):  
A. Fasso ◽  
K. Göbel ◽  
M. Höfert ◽  
J. Ranft ◽  
G. Stevenson
Keyword(s):  
Energy Region ◽  
High Energy ◽  
High Energy Region

scholarly journals HADRON PRODUCTION IN NEUTRINO–NUCLEON INTERACTIONS AT HIGH ENERGIES

2003 ◽  
Vol 18 (04) ◽  
pp. 673-683
Author(s):  
M. T. HUSSEIN ◽  
N. M. HASSAN ◽  
W. ELHARBI
Keyword(s):  
Cross Sections ◽  
Particle Production ◽  
High Energy ◽  
Neutrino Energy ◽  
Wave Functions ◽  
Variation Method ◽  
Hypothetical Model ◽  
High Energies ◽  
Color Field

The multi-particle productions in neutrino–nucleon collisions at high energy are investigated through the analysis of the data of the experiment CERN-WA-025 at neutrino energy less than 260 GeV and the experiments FNAL-616 and FNAL-701 at energy range 120–250 GeV. The general features of these experiments are used as base to build a hypothetical model that views the reaction through a Feynman diagram of two vertices. The first of which concerns the weak interaction between the neutrino and the quark constituents of the nucleon. At the second vertex, a strong color field is assumed to play the role of particle production, which depend on the momentum transferred from the first vertex. The wave functions of the nucleon constituent quarks are determined using the variation method and relevant boundary conditions are applied to calculate the deep inelastic cross sections of the virtual diagram.

Charge transfer in collisions of atomic hydrogen withN7+ions in the high-energy region

1987 ◽  
Vol 36 (4) ◽  
pp. 1656-1662 ◽  
Author(s):  
G. C. Saha ◽  
Shyamal Datta ◽  
S. C. Mukherjee
Keyword(s):  
Charge Transfer ◽  
Atomic Hydrogen ◽  
Energy Region ◽  
High Energy ◽  
High Energy Region

scholarly journals THE PROCESSES $gg\to\tilde\chi^+_i\tilde\chi^-_j$, $\tilde\chi^0_i\tilde\chi^0_j$ AT HIGH ENERGIES

2011 ◽  
Vol 26 (07n08) ◽  
pp. 1253-1272
Author(s):  
G. J. GOUNARIS ◽  
J. LAYSSAC ◽  
F. M. RENARD
Keyword(s):  
Cross Sections ◽  
High Energy ◽  
High Energies ◽  
Parity Conservation ◽  
Helicity Conservation ◽  
The One

According to the helicity conservation (HCns) theorem, the sum of the helicities should be conserved, in any 2-to-2 processes in MSSM with R-parity conservation, at high energies, i.e. all amplitudes violating this rule must vanish asymptotically. The realization of HCns in [Formula: see text], [Formula: see text] is studied, at the one-loop electroweak order, and simple high energy expressions are derived for the nonvanishing helicity conserving (HC) amplitudes. These are very similar to the corresponding expressions for gg → W+W-, ZZ, γZ, γγ derived before. Asymptotic relations among observable unpolarized cross-sections for many such processes are then obtained, some of which may hold at LHC-type energies.

A new approach for cross section evaluations in the high energy region

2009 ◽  
Vol 267 (11) ◽  
pp. 1882-1890
Author(s):  
Young-Sik Cho ◽  
Young-Ouk Lee ◽  
Guinyun Kim
Keyword(s):  
Cross Section ◽  
Energy Region ◽  
High Energy ◽  
High Energy Region ◽  
New Approach
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