BOSON INTERFEROMETRY: A REVIEW OF HIGH ENERGY DATA AND ITS INTERPRETATION

1989 ◽  
Vol 04 (12) ◽  
pp. 2861-2896 ◽  
Author(s):  
BENGT LÖRSTAD

Experimental data on the correlation of identical bosons are reviewed and the interpretation discussed. A revived interest in the study of the Bose-Einstein effect has evolved after new significant data from collisions at high energy. There is evidence that it looks the same in general events of all kinds of reactions and that the main variable in describing the effect is the absolute value of the four-momentum transfer Q. There is a dependence on multiplicity density at high energy, and furthermore there is an indication of a special reaction mechanism for selected events of very high multiplicity density. New experiments planned are dedicated to studies of the different aspects of this interference effect.

2018 ◽  
Vol 33 (33) ◽  
pp. 1850202 ◽  
Author(s):  
G. H. Arakelyan ◽  
C. Merino ◽  
Yu. M. Shabelski

We expose the current experimental and theoretical situation of the interesting case of the production of [Formula: see text] mesons in up to very high energy collisions of hadrons on both nucleon and nuclear targets, and we present a quantitatively good theoretical description of the corresponding experimental data, based on the formalism of the well established Quark–Gluon String Model, that has proved to be valid for a wide energy range. All the available experimental data for [Formula: see text]-meson production in hadron–nucleon collisions on the spectra of secondary [Formula: see text], and on the ratios of [Formula: see text] and [Formula: see text] production cross-sections, as well the corresponding ones for [Formula: see text]-meson production on nuclear targets, are considered. In particular, it is seen that the production of [Formula: see text]-mesons on nuclear targets presents unusually small shadow corrections for the inclusive density in the central rapidity region.


2005 ◽  
Vol 20 (29) ◽  
pp. 6846-6848 ◽  
Author(s):  
V. B. PETKOV

Knee formation in the EAS size spectrum as a possible result of some portion of EAS's energy carried away by some missing EAS component is discussed. To explain the absence of the bump in calculated EAS size spectrum for the standard EAS development in the present day experiments, the model of "catastrophic" EAS development was proposed. The hypothesis that all the energy lost for the further shower development ELT finally passes into neutrino (¾ELT) and muons (¼ELT) is shown to be practically excluded by present experimental data.


1964 ◽  
Vol 82 (1) ◽  
pp. 3-81 ◽  
Author(s):  
Evgenii L. Feinberg ◽  
Dmitrii S. Chernavskii

1986 ◽  
Vol 51 (4) ◽  
pp. 731-737
Author(s):  
Viliam Klimo ◽  
Jozef Tiňo

Geometry and energy parameters of the individual dissociation intermediate steps of CH4 molecule, parameters of the barrier to linearity and singlet-triplet separation of the CH2 molecule have been calculated by means of the UMP method in the minimum basis set augmented with the bond functions. The results agree well with experimental data except for the geometry of CH2(1A1) and relatively high energy values of CH(2II) and CH2(1A1) where the existence of two UHF solutions indicates a necessity of description of the electronic correlation by more exact methods of quantum chemistry.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
L. Whitmore ◽  
R. I. Mackay ◽  
M. van Herk ◽  
J. K. Jones ◽  
R. M. Jones

AbstractThis paper presents the first demonstration of deeply penetrating dose delivery using focused very high energy electron (VHEE) beams using quadrupole magnets in Monte Carlo simulations. We show that the focal point is readily modified by linearly changing the quadrupole magnet strength only. We also present a weighted sum of focused electron beams to form a spread-out electron peak (SOEP) over a target region. This has a significantly reduced entrance dose compared to a proton-based spread-out Bragg peak (SOBP). Very high energy electron (VHEE) beams are an exciting prospect in external beam radiotherapy. VHEEs are less sensitive to inhomogeneities than proton and photon beams, have a deep dose reach and could potentially be used to deliver FLASH radiotherapy. The dose distributions of unfocused VHEE produce high entrance and exit doses compared to other radiotherapy modalities unless focusing is employed, and in this case the entrance dose is considerably improved over existing radiations. We have investigated both symmetric and asymmetric focusing as well as focusing with a range of beam energies.


Author(s):  
DB Heyner ◽  
G Piazza ◽  
E Beeh ◽  
G Seidel ◽  
HE Friedrich ◽  
...  

A promising approach for the development of sustainable and resource-saving alternatives to conventional material solutions in vehicle structures is the use of renewable raw materials. One group of materials that has particular potential for this application is wood. The specific material properties of wood in the longitudinal fiber direction are comparable to typical construction materials such as steel or aluminum. Due to its comparatively low density, there is a very high lightweight construction potential especially for bending load cases. Structural components of the vehicle body are exposed to very high mechanical loads in the case of crash impact. Depending on the component under consideration, energy has to be absorbed and the structural integrity of the body has to be ensured in order to protect the occupants. The use of natural materials such as wood poses particular challenges for such applications. The material characteristics of wood are dispersed, and depend on environmental factors such as humidity. The aim of the following considerations was to develop a material system to ensure the functional reliability of the component. The test boundary conditions for validation also play a key role in this context. The potential of wood–steel hybrid design based on laminated veneer lumber and steel was investigated for use in a component subjected to crash loads such as the door impact beam. The chosen solution involves a separation of functions. A laminated veneer lumber-based beam was hybridized with a steel strip on the tension side. The steel strip was designed to compensate the comparatively low elongation at fracture of the wood and to ensure the integrity of the beam. The wooden component was designed for high energy absorption due to delamination and controlled failure during the impact, while maintaining the surface moment of inertia, i.e. the bending stiffness of the entire component. This approach was chosen to ensure the functional safety of the component, avoid sudden component failure and utilize the high potential of both materials. The tests carried out provided initial functional proof of the chosen solution. The hybridization achieved significantly higher deformations without sudden failure of the beam. In addition, bending capabilities were increased significantly compared to a beam without hybridization. In comparison with a state-of-the-art steel beam, the hybrid beam was not able to achieve the maximum deformation and the target weight of the hybrid beam. Further optimization of the hybrid beam is therefore necessary.


2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.


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