Resonance charge transfer between H(1s) and H + calculated by means of an approximation based on an expansion in atomic eigenfunctions

1961 ◽  
Vol 264 (1319) ◽  
pp. 547-557 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
High Energy ◽  
Wave Functions ◽  
Final States ◽  
Energy Limit ◽  
Full Account ◽  
The Cross ◽  
Resonance Charge

An expression for the cross-section describing electron capture by protons in atomic hydrogen is derived from an expansion based on atomic wave functions. Full account is taken of momentum transfer and of the non-orthogonality of the wave functions of the initial and final states by the method due to Bates. The cross-sections have been computed for proton energies from 100 to 1 MeV. In the low energy limit, the results agree with the p.s.s. calculations of Dalgarno & Yadav and in the high energy limit with the calculations of Brinkm an & Kramers.

Electron capture by fast protons and α-particles in hydrogen

1963 ◽  
Vol 272 (1351) ◽  
pp. 542-556 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Wave Functions ◽  
Final States ◽  
Resonance Case ◽  
Ion Energies ◽  
The Cross ◽  
Proper Allowance ◽  
Fast Protons ◽  
Α Particles

Cross-sections are calculated for the accidental resonance reaction, He 2+ + H(ls) -> He + (2s or 2p) + H + , and the non-resonance reaction, H + + H (ls)-> H(2s or 2p) + H + by means of the method due to Bates in which account is taken of the non-orthogonality of the wave functions describing the initial and final states. Proper allowance is made for the effects of distortion and of momentum transfer. The calculations are carried out for incident ion energies in the range 25 to 800 keV. In the accidental resonance case, the cross-section is small at low velocities of relative motion, and tends rapidly towards zero as the velocity is decreased in accordance with the prediction of Bates & Lynn. In all processes investigated the effect of distortion is considerable. Using the results of McCarroll & McElroy and of McCarroll for capture into the ground states of He + and H, the cross-sections for capture into all states are estimated. Comparisons are made with the experimental data of Fite, Smith & Stebbings for the incident alpha particle case and with that of Fite, Stebbings, Hummer & Brackman for the incident proton case. The highest energy for which cross-sections are measured in either case is however only 40 keV.

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.

Inelastic cross sections of nucleons and π mesons in carbon and lead near 100 GeV

1968 ◽  
Vol 46 (10) ◽  
pp. S694-S696 ◽  
Author(s):  
A. V. Alakoz ◽  
V. N. Bolotov ◽  
M. I. Devishev ◽  
L. F. Klimanova ◽  
A. P. Shmeleva
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Cosmic Ray ◽  
High Energy ◽  
Active Particle ◽  
Particle Interactions ◽  
Active Particles ◽  
The Cross

An experiment to measure the cross section for high-energy cosmic-ray neutrons and charged nuclear-active particle interactions with Pb and C nuclei has been carried out at an altitude of 2 000 m. Large spark chambers were used in a detector which selected neutrons and charged nuclear-active particles in the region of 100 GeV. The results are σπ(nPb) = (1.65 ± 0.17) barn, σπ(nC) = (0.204 ± 0.02) barn, σπ(πPb) = (1.53 ± 0.17) barn, σπ(πC) = (0.168 ± 0.017) barn.

scholarly journals Investigating Scalar Unparticle Production at Collisions with Polarized Beams in Unparticle Physics

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Le Nhu Thuc ◽  
Dao Thi Le Thuy
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Z Boson ◽  
Collision Energy ◽  
High Energy ◽  
Polarized Beams ◽  
Boson Exchange ◽  
The Cross ◽  
Muon Colliders ◽  
Energy Frontier

Scalar unparticle production in the process is studied from unparticle physics perspective. We have calculated and evaluated the cross sections for muon and Z boson exchange when the  beams are initially polarized. Numerical calculations show that the cross section of collisions depends strongly on the polarized condition of the initial beams and the collision energy . The results are plotted in the energy reach available at the present accelerators and the future high energy frontier muon colliders as shown in the scheme by Muon Accelerator Program (MAP) and other different colliders.

scholarly journals EMPIRICAL FORMALISM FOR PROJECTILE FRAGMENTATION AND PRODUCTION OF NEW NEUTRON-RICH NUCLEI WITH RIBS

1998 ◽  
Vol 13 (33) ◽  
pp. 2665-2678 ◽  
Author(s):  
DEBASIS BHOWMICK ◽  
ALOK CHAKRABARTI ◽  
D. N. BASU ◽  
PREMOMOY GHOSH ◽  
RANJANA GOSWAMI
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Ion Beam ◽  
Production Cross ◽  
High Energy ◽  
Exotic Nuclei ◽  
Radioactive Beams ◽  
Fragment Separator ◽  
Projectile Fragment ◽  
The Cross

The projectile fragment separator type radioactive ion beam (RIB) facilities, being developed in different laboratories, provide the scope for producing many new exotic nuclei through fragmentation of high energy radioactive ion (RI) beams. A new empirical parametrization for the estimation of cross-sections of projectile fragments has been prescribed for studying the advantages and limitations of high energy RI beams for the production of new exotic nuclei. The parametrization reproduces the experimental data for the production of fragments from neutron-rich projectiles accurately in contrast to the existing parametrization which tends to overestimate the cross-section of neutron-rich fragments in most cases. The modified formalism has been used to compute the cross-sections of neutron-rich species produced by fragmentation of radioactive projectiles (RIBs). It has been found that, given any limit of production cross-section, the exoticity of the fragment increases rather slowly and shows a saturation tendency as the projectile is made more and more exotic. This essentially limits, to an extent, the utility of very neutron-rich radioactive beams vis-a-vis production of new neutron-rich exotic species.

scholarly journals Deuteron breakup at zero angle in the Coulomb nuclear field

2019 ◽  
Vol 204 ◽  
pp. 10011
Author(s):  
Igor Sitnik
Keyword(s):  
Cross Section ◽  
High Precision ◽  
Cross Sections ◽  
High Energy Physics ◽  
Nuclear Research ◽  
High Energy ◽  
Deuteron Breakup ◽  
The Cross ◽  
Cross Section Maximum ◽  
Energy Physics

Deuteron breakup cross sections on the C and CH2 targets have been measured up to the proton internal momenta of 0.3 GeV/c. The cross-sections 12C(d, p)X and 1H(d, p)X reactions have been obtained with high precision. The obtained data are compared with previous measurements. The behavior features in the vicinity of the cross section maximum were studied in dependence on the transversal momentum in the region of 0.01 < pt < 0.16 GeV/c. The measurements have been performed at the Veksler Baldin Laboratory of High Energy Physics of the Joint Institute for Nuclear Research.

The application of variational methods to atomic scattering problems II. Impact excitation of the 2s level of atomic hydrogen-distorted wave treatment

1952 ◽  
Vol 212 (1111) ◽  
pp. 521-530 ◽  
Keyword(s):  
Cross Section ◽  
Atomic Hydrogen ◽  
Plane Waves ◽  
Wave Functions ◽  
Impact Excitation ◽  
Wave Method ◽  
Distorted Wave ◽  
Scattering Problems ◽  
The Cross ◽  
Distorted Wave Method

The cross-section for excitation of the 2 S level of atomic hydrogen by electrons is calculated using the distorted wave method with full allowance for exchange. The distorted wave functions used in the calculations are determined by Hulthèn’s variational method. The initial wave functions, representing the motion of an electron in the field of a normal atom with allowance for exchange, are taken to be those calculated by Massey & Moiseiwitsch (1950). The final wave functions, representing the motion of an electron in the field of a hydrogen atom in the 2 S state, have been obtained by a modification of the same method. Exchange effects are found to be less important in determining the forms of these wave functions. The cross-sections obtained are considerably smaller than those calculated by the Born-Oppenheimer method, in which the electron wave functions are undistorted plane waves. This is largely because the symmetrical cross-section, which has the greater weight in determining the mean cross-section, is much greater than the antisymmetrical according to the Born-Oppenheimer method, but the reverse is true if distortion is allowed for. In no case does the distorted wave method give results exceeding the theoretical upper limit, whereas with plane waves this limit is exceeded at certain electron energies by the symmetrical cross-section.

scholarly journals Hadron wave functions in high-energy scattering, form factors and strong decays: The effects of the Lorentz contracted form

2021 ◽  
Vol 36 (37) ◽  
Author(s):  
Yu. A. Simonov
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Lorentz Invariance ◽  
Form Factors ◽  
High Energy ◽  
Wave Functions ◽  
Large Momentum ◽  
Momentum Dependence ◽  
Lorentz Contraction ◽  
Energy Hadron

In this paper, we study the class of the processes, where dynamics depends essentially on the properties of the hadron wave functions involved in the reactions. In this case, the momentum dependence of the form of the wave functions, imposed by the Lorentz invariance and in particular by the Lorentz contraction, can be tested in the experiment and may strongly influence the resulting cross-sections. One example of such observables is given by the hadron form factors in the case when the large [Formula: see text] behavior is mostly frozen, while the Lorentz contraction of the hadron wave functions is taken into account. Another example, considered earlier, is the strong hadron decay with high-energy emission. In this paper, we study the role of the Lorentz contraction in the high-energy hadron–hadron scattering process at large momentum transfer. For the [Formula: see text] and [Formula: see text] scattering at large [Formula: see text], it is shown that at small [Formula: see text], the picture of two exponential slopes in the differential cross-section, explained previously by the author, remains stable, while the backward scattering cross-section is strongly increased by the Lorentz contraction.

Charge transfer in collisions involving symmetric and asymmetric resonance

1962 ◽  
Vol 268 (1335) ◽  
pp. 527-536 ◽  
Keyword(s):  
Charge Transfer ◽  
Energy Dependence ◽  
Cross Sections ◽  
Atomic Hydrogen ◽  
Zero Energy ◽  
Crossed Beams ◽  
The Cross ◽  
Resonance Charge ◽  
Symmetric Resonance

The cross-sections for charge transfer in collisions between atomic hydrogen and O + and He 2+ ions are presented. Unique interest attaches to these processes because they may occur with small or zero energy defect. Theoretical conflict exists regarding the magnitude and energy dependence of the cross-sections for accidental resonance collisions; the present work was prompted by the need for further information. Cross-sections for symmetric resonance charge transfer between protons and atomic hydrogen are also presented for energies down to 20 eV. The experiments were carried out by means of the techniques of modulated crossed beams.

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