scholarly journals Nucleon form factors at threshold

2019 ◽  
Vol 218 ◽  
pp. 04003
Author(s):  
Alexandr Milstein
Keyword(s):  
Invariant Mass ◽  
Cross Section ◽  
Cross Sections ◽  
Mass Spectra ◽  
Form Factors ◽  
Invariant Mass Spectrum ◽  
Nucleon Form Factors ◽  
The Cross ◽  
Good Agreement ◽  
Invariant Mass Spectra

The pp¯invariant mass spectra in the processes e+e−→ pp¯, e+e−→ nn¯, J/ψ → pp¯ω, J/ψ → pp¯ρ, and J/ψ → pp¯γ close to the pp¯is discussed. The optical potentials for NN¯pair in the superposition of S and D waves (due to tensor forces) at spin unity of the pair, as well as for NN¯pair in the S wave at spin zero of the pair, are proposed. The parameters of the potentials are obtained by fitting the cross sections of NN¯scattering together with the pp¯invariant mass spectra in e+e−→ pp¯annihilation and J/ψ decays. Good agreement with the available experimental data is achieved. Using our potential and the Green’s function approach we also describe the cross section of e+ e−→ 6π and the η’π+ π− invariant mass spectrum in the decay J/ψ → γη’π+π− in the energy region near the NN¯threshold.

scholarly journals Evaluation of the Compton (Incoherent) and Rayleigh (Coherent) Differential Cross Sections of Scattering for Rhodium 103Rh45 and Tantalum181Ta73 by Employing CSC model

2012 ◽  
Vol 9 (3) ◽  
pp. 554-558 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Differential Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Differential Cross ◽  
Form Factors ◽  
Differential Cross Sections ◽  
The Cross

The differential cross section for the Rhodium and Tantalum has been calculated by using the Cross Section Calculations (CSC) in range of energy(1keV-1MeV) . This calculations based on the programming of the Klein-Nashina and Rayleigh Equations. Atomic form factors as well as the coherent functions in Fortran90 language Machine proved very fast an accurate results and the possibility of application of such model to obtain the total coefficient for any elements or compounds.

THE PROCESSES e+e−→W±H∓AND e+e−→H+H−IN SUPERSTRING INSPIRED EXTRA U(1) MODEL

1990 ◽  
Vol 05 (03) ◽  
pp. 501-514 ◽  
Author(s):  
USHA BHATIA ◽  
N.K. SHARMA
Keyword(s):  
Mass Spectrum ◽  
Invariant Mass ◽  
Cross Section ◽  
Polar Angle ◽  
Invariant Mass Spectrum ◽  
Thrust Axis ◽  
The Cross

We investigate the processes e+e−→W±H∓ and e+e−→H+H− in a superstring inspired model having an additional ZE. The cross section at Z2 resonance for e+e−→W±H∓ are considerably large, giving about a thousand events per day at LEP II energy for the planned luminosity. The invariant mass spectrum for l±vl obtained from W± decay is shown to be distinct and could be decisive in the detection of the process. The cross section for the process e+e−→H+H− is relatively small and may provide around five events per day for the envisaged luminosity. The dominant background problem caused by e+e−→W+W− in both processes may be reduced by applying appropriate cuts on the polar angle of the thrust axis.

A new empirical formula for cross-sections of (n,nα) reactions

2020 ◽  
Vol 29 (08) ◽  
pp. 2050062
Author(s):  
Mustafa Yiğit
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Empirical Formula ◽  
Nuclear Reactions ◽  
Measured Cross Section ◽  
Future Studies ◽  
Present Formalism ◽  
The Cross ◽  
Neutron Cross Sections ◽  
Good Agreement

Studies on the cross-sections of (n,n[Formula: see text]) reactions which are energetically possible, about 14 MeV neutrons are quite scarce. In this paper, the cross-sections of (n,n[Formula: see text] nuclear reactions at [Formula: see text]14–15 MeV are analyzed by using a new empirical formula based on the statistical theory. We show that neutron cross-sections are closely related to the [Formula: see text]-value of nuclear reaction, in particular for (n,n[Formula: see text]) channels. Results obtained with this empirical formula show good agreement with the available measured cross-section values. We hope that the estimations on the cross-sections using the present formalism may be helpful in future studies in this field.

scholarly journals Cross Section Ionization By Electron Impact Of Helium Like Ions

2021 ◽  
Author(s):  
Manel Hariz Belgacem ◽  
Elhabib Guedda ◽  
Haikel Jelassi
Keyword(s):  
Electron Impact ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
The Cross ◽  
State 1 ◽  
Unstable States ◽  
Good Agreement

<sub></sub> In this paper we present our calculation of the cross section ionization by electron impact of C V, N VI and O VII. Using the Flexible Atomic Code (FAC), we obtain the cross sections for the ionization of these ions from the ground state 1<sup>1</sup>S, and from the unstable states 2<sup>1</sup>S and 2<sup>3</sup>S. Our results are in good agreement with those based on the Coulomb Born (CB) approximation and the available measurements.

scholarly journals 14.8 MeV Neutron Activation Cross Section Measurements for Ge Isotopes

2009 ◽  
Vol 1 (2) ◽  
pp. 173-181 ◽  
Author(s):  
M. M. Haque ◽  
M. T. Islam ◽  
M. A. Hafiz ◽  
R. U. Miah ◽  
M. S. Uddin
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Gamma Ray ◽  
Reaction Cross ◽  
Activation Cross Section ◽  
Section Data ◽  
Gamma Ray Spectroscopy ◽  
24Na Reaction ◽  
The Cross ◽  
Good Agreement

The cross sections of Ge isotopes were measured with the activation method at 14.8 MeV neutron energy. The quasi-monoenergetic neutron beams were produced via the 3H(d,n)4He reaction at the 150 kV J-25 neutron generator of INST, AERE. The characteristics γ-lines of the product nuclei were measured with a closed end coaxial 17.5 cm2 high purity germanium (HPGe) detector gamma ray spectroscopy. The cross sections were determined with reference to the known 27Al(n,α)24Na reaction. Cross section data are presented for 72Ge(n,p)72Ga, 74Ge(n,α)71mZn and 76Ge(n,2n)75m+gGe reactions. The cross section values obtained for the above reactions were 24.78±1.75 mb, 1.69±0.11 mb and 860±50 mb, respectively. The results obtained were compared with the values reported in literature as well as theoretical calculation performed by the statistical code SINCROS-II. The experimental data were found fairly in good agreement with the calculated and literature data.  Keywords: Activation cross section; Neutron induced reaction; Gamma-ray spectroscopy; 14.8 MeV. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i2.1532  

Many-Electron Correlations in the Photoionization of a Nitrogen Atom

1974 ◽  
Vol 52 (4) ◽  
pp. 349-354 ◽  
Author(s):  
N. A. Cherepkov ◽  
L. V. Chernysheva ◽  
V. Radojević ◽  
I. Pavlin
Keyword(s):  
Nitrogen Atom ◽  
Cross Section ◽  
Cross Sections ◽  
Random Phase Approximation ◽  
Random Phase ◽  
Electron Correlations ◽  
Sum Rule ◽  
Hartree Fock ◽  
The Cross ◽  
Good Agreement

Photoionization cross sections for the outer shell of the nitrogen atom ground state are calculated in the single-particle Hartree–Fock approximation and, in order to take into account many-electron correlations, also in the Random Phase Approximation with Exchange (RPAE). To be able to apply the RPAE, its modification for the half-filled shell atom, such as nitrogen atom, is presented. Calculation of length and velocity forms of the cross section in both approximations are compared with the available experimental data, and a good agreement is obtained. It has been found that in the RPAE the influence of many-electron correlations in a nitrogen atom is not great, but it is very important since, in contrast to the Hartree–Fock approximation, it results in the validity of the sum rule and the coincidence of the length and velocity forms of the cross sections, in agreement with the requirement of the general theory. The angular distribution of photoelectrons is also calculated in the RPAE, which has not been measured so far.

scholarly journals Interaction of real and virtual NN̅ pairs in J/ψ decays

2018 ◽  
Vol 181 ◽  
pp. 01020
Author(s):  
Alexander Milstein ◽  
Sergey Salnikov
Keyword(s):  
Experimental Data ◽  
Mass Spectrum ◽  
Invariant Mass ◽  
Cross Sections ◽  
Energy Region ◽  
Mass Spectra ◽  
Optical Potential ◽  
Invariant Mass Spectrum ◽  
Decay Rates ◽  
Angular Distributions

The differential decay rates of the processes J/ψ→pp̅π0, J/ψ→pp̅η, J/ψ→pp̅ω, J/ψ→pp̅ρ, and J/ψ→pp̅γ close to the pp̅ threshold are calculated with the help of the NN̅ optical potential. We use the potential which has been suggested to fit the cross sections of NN̅ scattering together with all other NN̅ experimental data available. The pp̅ nvariant mass spectra of J/ψ decays are in agreement with the available experimental data. The anisotropy of the angular distributions of the decays J/ψ→pp̅π0(η), which appears due to the tensor forces in the NN̅ interaction, is predicted close to the pp̅ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of NN̅ interaction, is predicted close to the pp̅ threshold. This anisotropy is large enough to be investigated experimentally. Such measurements would allow one to check the accuracy of the model of NN̅ interaction. Using our potential and the Green’s function approach we also describe the peak in the η′ π+ π- invariant mass spectrum in the decay J/ψ → γ η′ π+ π- in the energy region near the NN̅ threshold.

The effects of nucleus form factors on the electromagnetically produced heavy lepton pairs

2016 ◽  
Vol 25 (02) ◽  
pp. 1650006 ◽  
Author(s):  
M. Y. Şengül
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Form Factors ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Lepton Pairs ◽  
Heavy Lepton ◽  
Ion Collisions ◽  
Realistic Form ◽  
The Cross

In this paper, the effects of different nucleus form factors to the cross-sections of electromagnetically produced heavy lepton pairs such as muons and tauons from the ultra-relativistic heavy ion collisions have been calculated. Nucleus form factors play important roles in the calculation of the cross-sections, because the Compton wavelengths of muon and tauon are comparable to the radius of the colliding ions. Some realistic form factors in these calculations have been used and compared the results among them. It has been shown that nucleus form factors reduce the cross-section calculations for muon and tauon pair production very strongly especially at RHIC energies.

scholarly journals ON A POSSIBLE MANIFESTATION OF THE FOUR-COLOR SYMMETRY Z' BOSON IN μ+μ- EVENTS AT THE LHC

2009 ◽  
Vol 24 (15) ◽  
pp. 1199-1207
Author(s):  
A. D. SMIRNOV ◽  
YU. S. ZAITSEV
Keyword(s):  
Mass Spectrum ◽  
Pair Production ◽  
Invariant Mass ◽  
Cross Section ◽  
Z Boson ◽  
Invariant Mass Spectrum ◽  
Mass Region ◽  
Pp Collisions ◽  
Color Symmetry ◽  
The Cross

The cross section of the μ+μ- pair production in pp-collisions at the LHC is calculated with account of the Z' boson induced by the minimal four-color quark–lepton symmetry (MQLS). The μ+μ- invariant mass spectrum with account of the MQLS Z' boson is analyzed in dependence on the Z' mass. The mass region for the MQLS Z' boson observable at the LHC is found in dependence on the significance and on the integrated luminosity.

TWO-NEUTRON CORRELATIONS IN HALO NUCLEI VIA COULOMB BREAKUP REACTIONS

2011 ◽  
Vol 20 (04) ◽  
pp. 843-846
Author(s):  
YUMA KIKUCHI ◽  
KIYOSHI KATŌ ◽  
TAKAYUKI MYO ◽  
MASAAKI TAKASHINA ◽  
KIYOMI IKEDA
Keyword(s):  
Invariant Mass ◽  
Cross Section ◽  
Mass Spectra ◽  
Halo Nucleus ◽  
Breakup Cross Section ◽  
Halo Nuclei ◽  
Neutron Halo ◽  
Coulomb Breakup ◽  
Three Body ◽  
Invariant Mass Spectra

We investigate the three-body Coulomb breakup of a two-neutron halo nucleus, 6 He . We calculate the breakup cross section and the invariant mass spectra by using the complex-scaled solutions of the Lippmann-Schwinger equation, and discuss the relations between the structures in these observables and the n-n and α-n correlations in 6 He .

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