A GLOBAL TEST OF FACTORIZATION FOR NUCLEON–NUCLEON, γp AND γγ SCATTERING

2005 ◽  
Vol 20 (13) ◽  
pp. 2781-2793 ◽  
Author(s):  
MARTIN M. BLOCK ◽  
KYUNGSIK KANG
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Nucleon Nucleon ◽  
Vector Meson Dominance ◽  
Global Test ◽  
Section Data ◽  
Energy Domain ◽  
The Cross ◽  
Factorization Relation

The purpose of this paper is to show that the cross-section factorization relation σnn(s)/σγp(s) = σγp(s)/σγγ(s) is satisfied experimentally in the energy domain [Formula: see text], where the σ's are total cross-sections and nn denotes the even portion of the pp and [Formula: see text] total cross-section. A convenient phenomenological parametrization for a global simultaneous fit to the pp, [Formula: see text], γp and γγ total cross-section data together with the ρ-value data for pp and [Formula: see text] is provided by using real analytic amplitudes. Within experimental errors, we show that factorization is satisfied when we unfold the published γγ data which had averaged the cross-sections obtained by using the two different PHOJET and PYTHIA Monte Carlo results. Our analysis clearly favors the PHOJET results and suggests that the additive quark model, together with vector meson dominance, allows one to compute σγp(s) and σγγ(s) from σnn(s) with essentially no free parameters. The universal ρ-value predicted by our fit, i.e. ρnn = ργp = ργγ, is compared to the ρ-value obtained by a QCD-inspired analysis of [Formula: see text] and pp data, including the p-air cross-sections from cosmic rays. The ρ-values obtained from the two techniques are essentially indistinguishable in the energy region [Formula: see text], giving us increased confidence in our parametrization of the cross-sections needed for the factorization relation.

DOUBLE PION PHOTOPRODUCTION EXPERIMENT AT LNS–TOHOKU

2008 ◽  
Vol 23 (27n30) ◽  
pp. 2313-2316 ◽  
Author(s):  
◽  
H. KANDA ◽  
N. CHIGA ◽  
Y. FUJII ◽  
K. FUTATSUKAWA ◽  
...  
Keyword(s):  
Total Cross Section ◽  
Energy Range ◽  
Cross Section ◽  
Cross Sections ◽  
Pion Photoproduction ◽  
Total Cross Sections ◽  
Free Proton ◽  
Double Pion ◽  
The Cross

The total cross sections for the π+π− photoproduction on the deuteron were measured in an energy range of 0.8 to 1.1 GeV. The obtained total cross section for the quasi-free π+π− photoproduction on the deuteron was about 60 % of those on the free proton. The cross section for Δ++Δ− photoproduction was derived from the non-quasi-free π+π− photoproduction events. It was smaller than the previous data.

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  

On a model for a time series of cross-sections

1986 ◽  
Vol 23 (A) ◽  
pp. 113-125 ◽  
Author(s):  
P. M. Robinson
Keyword(s):  
Time Series ◽  
Cross Section ◽  
Cross Sections ◽  
Standard Form ◽  
Cross Sectional ◽  
Aggregated Data ◽  
Section Data ◽  
Infinite Population ◽  
The Cross ◽  
Observation Times

Dynamic stationary models for mixed time series and cross-section data are studied. The models are of simple, standard form except that the unknown coefficients are not assumed constant over the cross-section; instead, each cross-sectional unit draws a parameter set from an infinite population. The models are framed in continuous time, which facilitates the handling of irregularly-spaced series, and observation times that vary over the cross-section, and covers also standard cases in which observations at the same regularly-spaced times are available for each unit. A variety of issues are considered, in particular stationarity and distributional questions, inference about the parameter distributions, and the behaviour of cross-sectionally aggregated data.

scholarly journals Use of Nuclear Data Sensitivity and Uncertainty Analysis for the Design Preparation of the HCLL Breeder Blanket Mockup Experiment for ITER

2008 ◽  
Vol 2008 ◽  
pp. 1-5
Author(s):  
I. Kodeli
Keyword(s):  
Uncertainty Analysis ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Data ◽  
Maximum Information ◽  
Tritium Production ◽  
Section Data ◽  
Combined Use ◽  
Deterministic Transport ◽  
The Cross

An experiment on a mockup of the test blanket module based on helium-cooled lithium lead (HCLL) concept will be performed in 2008 in the Frascati Neutron Generator (FNG) in order to study neutronics characteristics of the module and the accuracy of the computational tools. With the objective to prepare and optimise the design of the mockup in the sense to provide maximum information on the state-of-the-art of the cross-section data the mockup was pre-analysed using the deterministic codes for the sensitivity/uncertainty analysis. The neutron fluxes and tritium production rate (TPR), their sensitivity to the underlying basic cross-sections, as well as the corresponding uncertainties were calculated using the deterministic transport codes (DOORS package), the sensitivity/uncertainty code package SUSD3D, and the VITAMINJ/ COVA covariance matrix libraries. The cross-section reactions with largest contribution to the uncertainty of the calculated TPR were identified to be (n,2n) and (n,3n) reactions on lead. The conclusions of this work support the main benchmark design and suggest some modifications and improvements. In particular this study recommends the use, as far as possible, of both natural and enriched lithium pellets for the TRP measurements. The combined use is expected to provide additional and complementary information on the sensitive cross-sections.

Discrepancy of in-medium nucleon–nucleon cross-section in different T-matrix representations

2014 ◽  
Vol 23 (04) ◽  
pp. 1450023 ◽  
Author(s):  
Yong-Zhong Xing ◽  
Xing-Wen Zhao
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nucleon Nucleon ◽  
Matrix Representations ◽  
Proton Proton ◽  
Hartree Fock ◽  
Wave States ◽  
T Matrix ◽  
The Cross ◽  
Three Body

In this paper, we study the in-medium nucleon–nucleon (NN) cross-section by using the Dirac–Breuckner–Hartree–Fock approximation (DBHF) with T-matrix project technique for determining the nucleon self-energy. By solving Thompson equation for different partial-wave states separately, we find that the discrepancies of nucleon self-energies in various T-matrix project representations are dominated by the channels with smaller angular momentum. Although the cross-section is independent on the project of T-matrix, the medium suppression of the cross-section in various T-matrix representations are apparently different due to the self-consistency of DBHF calculation involving effect mass of nucleon as an iterative parameter. Our results also show that the cross-sections in the complete pseudovector (CPV) choices are larger than those obtained with both DBHF in the pseudoscalar (PS) choice and nonrelativistic Brueckner–Hartree–Fock with three-body force (BHF + 3BF), respectively. Further comparison shows that the neutron–proton (NP) cross-section within DBHF + PV approach, [Formula: see text], is approximately equal to and slightly larger than that evaluated with BHF + 3BF, [Formula: see text], while the neutron–neutron (NN) (or proton–proton (PP)) cross-section given by DBHF + PV method, [Formula: see text], being the closest to the cross-section calculated by using BHF without 3BF in the lower energy region. Additionally, the discrepancies of the in-medium nucleon–nucleon differential cross-section induced by different representations of T-matrix in DBHF are discussed for nuclear matter with different densities.

scholarly journals Elastic and inelastic cross-sections of the mercury atom

1935 ◽  
Vol 151 (873) ◽  
pp. 256-274 ◽  
Author(s):  
F. L. Arnot ◽  
G. O. Baines ◽  
Herbert Stanley Allen
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Inelastic Collision ◽  
Elastic Collision ◽  
Mercury Atom ◽  
Discrete Energy ◽  
Complete Knowledge ◽  
Collision Processes ◽  
The Cross

A considerable amount of experimental work has been done in investigating the total cross-section of an atom for collision with an electron in various gases. The total cross-section is measured by determining the number of electrons deflected out of a homogeneous beam, or which have their energy decreased, as the beam passes through the gas. For a complete knowledge of collision processes, it is necessary to know not only the total cross-section for collision but also the cross-section of the atom for various specific types of collision. The total cross-section can be divided into two main partial cross-sections—that for elastic collision and that for inelastic collision. The latter may be subdivided into the cross-section for excitation and the cross-section for ionization. The cross-section for excitation may then be further subdivided into the various cross-sections pertaining to the numerous discrete energy losses that the electron may suffer in its collision with the atom.

scholarly journals Analysis of the fusion cross sections for 16,18,20O + 12C systems at low energies

2019 ◽  
Vol 97 (7) ◽  
pp. 803-807 ◽  
Author(s):  
G. Kocak
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Optical Model ◽  
Fusion Cross Section ◽  
Nucleon Nucleon ◽  
Cross Section Data ◽  
Section Data ◽  
Low Energies ◽  
Double Folding ◽  
Good Agreement

Fusion cross section data for the 16,18,20O + 12C systems at energies near and below the Coulomb barrier are studied within the framework of the optical model. To examine these reactions, the microscopic nucleon–nucleon double folding potentials for real and imaginary parts are found. To make a comprehensive analysis of the effect of neutron-rich systems, we used three different reactions from stable to unstable systems. The microscopic nucleon–nucleon double folding potentials show very good agreement for 16,18,20O + 12C systems with a very weak imaginary potential. Also, we have obtained better agreement by using fully microscopic nucleon–nucleon double folding potentials with the 20O + 12C system’s experimental data than in previous works, but especially at low energies we still have some problems reproducing the 20O + 12C system’s fusion cross section data.

On a model for a time series of cross-sections

1986 ◽  
Vol 23 (A) ◽  
pp. 113-125
Author(s):  
P. M. Robinson
Keyword(s):  
Time Series ◽  
Cross Section ◽  
Cross Sections ◽  
Standard Form ◽  
Cross Sectional ◽  
Aggregated Data ◽  
Section Data ◽  
Infinite Population ◽  
The Cross ◽  
Observation Times

Dynamic stationary models for mixed time series and cross-section data are studied. The models are of simple, standard form except that the unknown coefficients are not assumed constant over the cross-section; instead, each cross-sectional unit draws a parameter set from an infinite population. The models are framed in continuous time, which facilitates the handling of irregularly-spaced series, and observation times that vary over the cross-section, and covers also standard cases in which observations at the same regularly-spaced times are available for each unit. A variety of issues are considered, in particular stationarity and distributional questions, inference about the parameter distributions, and the behaviour of cross-sectionally aggregated data.

scholarly journals Production Cross Sections of Axion in a Static Electromagnetic Field

2013 ◽  
Vol 23 (1) ◽  
pp. 21
Author(s):  
Dang Van Soa ◽  
Tran Dinh Tham
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Electric Field ◽  
Total Cross Section ◽  
Strong Magnetic Field ◽  
Cross Section ◽  
Cross Sections ◽  
Feynman Diagram ◽  
Production Cross ◽  
The Cross

Photon - axion conversions in staticelectromagnetic fields of the size \(a\times b \times c\) areconsidered in detail by the Feynman diagram methods. Thedifferential cross sections are presented and the numericalevaluations of the total cross section are given. Our result showsthat the conversion cross-sections in the electric field are quitesmall, while in the strong magnetic field, the cross-sections are much enhanced, which can be measurable in current experiments.

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