Nuclear Interaction Cross Sections Research Articles

The charge and mass dependence of nuclear interaction cross sections

Abstract The Thomas-Fermi model of Seyler and Blanchard is employed for the purpose of calculating the interaction cross sections of nuclei as a function of charge and mass. Comparison is made with the Bevalac experiments of Tanihata et al .

Geometric scaling and nuclear interaction cross sections at ultrarelativistic energies

view Abstract Citations (4) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Geometric Scaling of Nuclear Interaction Cross Sections at Ultrarelativistic Energies Karol, P. J. Abstract Use is made of recent experimental results that have shown the elementary nucleon-nucleon cross section at ultrarelativistic energies increasing as log-squared E. The principle of geometric scaling implies that the effective size of the nucleon scales to the same degree. When geometric scaling is combined with the 'soft spheres model' for nuclear interaction cross sections, one may calculate the interaction probabilities of target-projectile systems at energies corresponding to the highest seen for cosmic rays. The model is readily applied to strongly interacting elementary particles including antiparticles as well as to complex nuclei. Cosmic ray interaction cross sections calculated at ultrarelativistic energies are found to increase substantially. Publication: The Astrophysical Journal Pub Date: September 1988 DOI: 10.1086/166680 Bibcode: 1988ApJ...332..615K Keywords: High Energy Interactions; Nuclear Astrophysics; Nuclear Interactions; Relativistic Particles; Relic Radiation; Astronomical Models; Hadrons; Red Shift; Space Radiation; COSMIC RAYS: GENERAL; NUCLEAR REACTIONS full text sources ADS |

Nuclear Interactions of High-Energy Cosmic Rays Observed near Sea Level

Nuclear interactions of magnetically analyzed cosmic rays above 8 Bev are observed near sea level at two zenith angles, 0 and 68 deg , in an effort to obtain information on the nuon nuclear interaction cross section for events of ~200 Mev threshold energy, and on the vertical intensity of sealevel protons having ~20 Bev median energy. The muons selected are comparable in energy to those at an underground depth of ~ 300 meters water equivalent (m.w.e.). The result agrees with data at 310 and 590 m.w.e. All three points, however, lie above the cross sections calculated with the Williams-Weizsacker method. In view of large statistical errors the departure cannot be taken too seriously, but it suggests an increase of photonuclear cross section with energy. The statistical error in the derived proton intensity is also large. The average elasticity of high-energy nuclear collisions consistent with the observed proton intensity is roughly 50%. The spectral point indicates a differential proton spectrum that can be represented by a power law with exponent gamma 1.9 plus or minus 0.3. The spectrum of primary particles that contribute to the sea-level proton flux in the 1 to 20 Bev energy range fits a power lawmore » with gamma approx equal 2.4. The fact that the sea-level spectrum is harder than the primary spectrum suggests that the elasticity is an increasing function of energy. (auth)« less

On some interaction characteristics of very high-energy particles and their interpretation from the view point of the hydrodymical yheory of multiple particles production

S>Landau, using the idea stated by Fermi, employed relativistic hydrodynamics in describing very high energy particle collision. The first attempts to compare the conclusions of hydrodynamical theory with experimental data on the multiplicity and angular and energy distributions of secondary particles already showed that the hydrodynamical theory satisfactorily described many multiple process characteristics. By comparison of the theory with experimental data taken from the analysis of showers recorded in photographic emulsion, a number of essential additional assurnptions were made. These assumptions caused a certain obscurity of the conclusions. For example, it was assumed that the collision of nucleons with heavy nuclei took place in the coordinate system in which notion of substance was symmetrical. Extensive shower analysis carried out on the assumption that the nuclear interaction cross section is independent of energy shows that the formal part of the hydrodynamical theory is incomplete. (A.C.)

Nuclear Interaction ofμ-Mesons Underground

The nuclear interactions of $\ensuremath{\mu}$-mesons and the genetic relations among their secondary particles are analyzed on the basis of the data obtained with photographic plates exposed underground by George and Evans. The results are used to analyze the experiment performed by Cocconi and Tongiorgi, in which the neutron showers produced in an absorber at different depths of water were studied. The contributions to the neutron showers from various components are compared. It is shown that the $\ensuremath{\mu}$-mesons directly producing neutron showers in the absorber and the nucleons produced by the $\ensuremath{\mu}$-mesons in the water above the apparatus and interacting in the absorber give the main contribution to the large neutron showers observed. The multiplicity spectrum of the neutrons is calculated by making use of a simplified model of the nucleon cascade and is shown to depend upon the selection bias of the detecting apparatus. The experimental results are consistently accounted for by assuming for the $\ensuremath{\mu}$-mesons a nuclear interaction cross section of \ensuremath{\sim}10 \ensuremath{\mu}b per nucleon. The experiments at great depths suggest the predominance of small momentum transfers by nuclear collisions. The large cross section and the small momentum transfer can be described in terms of the virtual photons associated with $\ensuremath{\mu}$-mesons. These virtual photons produce in nuclear collisions real or virtual $\ensuremath{\pi}$-mesons which can either escape or be absorbed in the nucleus.