Proton-deuteron interactions at 970 MeV

A high-pressure diffusion cloud chamber has been used to study the interactions of 970 MeV protons from the Birmingham synchrotron with deuterium. Analysis of the 569 collisions observed indicates that at this energy the deuteron behaves as if it were composed of two free nucleons. The properties of proton-proton and proton-neutron scattering have been determined on this assumption. An estimate is made of the extent of the ‘shadowing’ of each nucleon in the deuteron by the other. The partial cross-sections for p-p and p-n elastic scattering have been determined, as have also the values for the five possible single meson production processes. They have the following ‘best’ values: (1) ( p + p-> p + p ) = 25.9 + 1.7 mb, (2) ( p + n-> p + n ) = 16.2 + 3.5 mb, (3) ( p + p-> p + p + 7T 0 ) = 5.4 + 1.0 mb, (4) ( p + p -> n + p + 7T + ) = 15.6 + 1.7 mb, (5) ( p + n-> p + n + n 0 ) = 14.3 + 3.5 mb, (6) ( p + n-+ p + p + 7T - ) = 2.7 + 0.6mb, (7) ( p + n-> n + n + 7T + ) = 4.3 + 1.1 mb. Double meson production and reactions involving secondary deuterons are not important. The cross-sections (1), (2), (3), (4) and (5) are consistent with values extrapolated from data at energies below 660 MeV by Russian workers. Knowledge of the other cross-sections (6) and (7) makes possible a test of the validity of the charge independence of nuclear forces. The present results are not in good agreement with this. The results for inelastic scattering indicate that, assuming charge independence, the formation of excited nucleons of isotopic spin 3/2 does not dominate the process of pion production. This is also true for the Russian data. Twelve cases of double meson production were observed. The angular distribution of proton-neutron elastic scattering has the form expected from lower energy data.

The interaction of 970 MeV protons with helium has been studied with a high-pressure diffusion cloud chamber. From 642 events the total and absorption cross-sections were found to be 116 ± 17 mb and 93 ± 13 mb, respectively. These agree with values obtained by extrapolation of known cross-sections for more complex nuclei, and the results are interpreted in terms of the optical model of the nucleus. The angular distribution for elastic-scattering yields an α -particle radius of 1⋅8 x 10 -13 cm. Quasi-elastic proton-proton and proton-neutron scattering, and more particularly charged meson production, show that the α -particle has some individual particle characteristics. Meson reabsorption appears unimportant.


2002 ◽  
Vol 11 (05) ◽  
pp. 425-436 ◽  
Author(s):  
M. Y. H. FARAG ◽  
M. Y. M. HASSAN

The relativistic description of the proton-nucleus elastic scattering can be considered within the framework of a relativistic optical potential model. The elastic scattering of proton with the nuclei 12 C , 16 O , 20 Ne , and 24 Mg at 800 MeV and 1.04 GeV are studied for relativistic and nonrelativistic treatments. The real optical potentials and the differential cross sections of these reactions are calculated. The obtained results are compared with the corresponding results obtained from the calculation depending on the Woods–Saxon optical potential which were adjusted to fit the experimental data. The present results are in good agreement with the experimental data.


2019 ◽  
Vol 28 (09) ◽  
pp. 1950074
Author(s):  
Zakaria M. M. Mahmoud ◽  
Awad A. Ibraheem ◽  
M. A. Hassanain

In this work, we simultaneously reanalyzed the differential elastic scattering cross-sections ([Formula: see text]) and the vector analyzing power ([Formula: see text]) of [Formula: see text]He elastic scattering. This analysis was performed using the folded optical model for both real central and spin-orbit (SO) potentials, respectively. For the imaginary central, we used the usual Woods-Saxon (WS) form. Three different model density distributions are used to calculate the potential. We aimed to examine the applicability of the microscopically derived SO potential and the structure effect of 6He nucleus. The presence of the [Formula: see text] experimental data of [Formula: see text]He makes it interesting for this study. Our calculations showed that the three densities gave similar predictions for the cross-sections data. The three microscopic SO potentials calculations of [Formula: see text] are not in a good agreement with the experimental data. We concluded that the SO formalism in its current form needs more investigations for exotic halo nuclei.


2015 ◽  
Vol 30 (08) ◽  
pp. 1542006 ◽  
Author(s):  
Claude Bourrely ◽  
Jacques Soffer ◽  
Tai Tsun Wu

In 1970, on purely theoretical grounds, all total hadronic total cross-sections were predicted to increase without limit for higher and higher energies. This was contrary to the conventional belief at that time. In 1978, an accurate phenomenological model was formulated for the case of proton–proton and antiproton-proton interactions. The parameters for this model were slightly improved in 1984 using the additional available experimental data. Since then, for 30 years these parameters have not changed. This development, including especially the difficult task of formulating this phenomenological model and the comparison of the predictions of this model with later experimental results, is summarized.


The main features of the C. E. R. N. Intersecting Storage Rings (I. S. R.) are reviewed, together with results obtained in 1971 and 1972 on elastic scattering and total cross-sections. The main result is a 10% increase of the total proton-proton cross-section in the I. S. R. energy range. The simplest picture of high energy proton-proton scattering which emerges from this and the other data, is briefly discussed.


A summary of the work carried out at the Institute for High-Energy Physics, Serpukhov, U. S. S. R., on proton-proton interactions at energies between 10 and 70 GeV is given. The experiments comprise studies of small angle elastic scattering, of total cross-sections and of interactions in a hydrogen bubble chamber.


1992 ◽  
Vol 70 (5) ◽  
pp. 305-310 ◽  
Author(s):  
Y. Frongillo ◽  
B. Plenkiewicz ◽  
P. Plenkiewicz ◽  
J.-P. Jay-Gerin

Pseudopotential calculations of phase shifts, differential, total, and momentum-transfer cross sections for electrons elastically scattered from neon atoms are reported in the impact energy range 0–20 eV. The results are found to be in very good agreement with existing experimental and other theoretical data.


2011 ◽  
Vol 20 (05) ◽  
pp. 1243-1270 ◽  
Author(s):  
A. I. AHMADOV ◽  
R. M. BURJALIYEV

In this paper, we investigate the next-to-leading order contribution of the higher-twist Feynman diagrams to the large-pT inclusive pion production cross-section in proton–proton collisions and present the general formulae for the higher-twist differential cross-sections in the case of the running coupling and frozen coupling approaches. We compared the resummed next-to-leading order higher-twist cross-sections with the ones obtained in the framework of the frozen coupling approach and leading-twist cross-section. The structure of infrared renormalon singularities of the higher-twist subprocess cross-section and its resummed expression (the Borel sum) are found. It is shown that the resummed result depends on the choice of the meson wave functions used in the calculations. We discuss the phenomenological consequences of possible higher-twist contributions to the meson production in proton–proton collisions in next-to-leading order at RHIC.


2019 ◽  
Vol 65 (4 Jul-Aug) ◽  
pp. 404
Author(s):  
M. Aygun ◽  
And Z. Aygun

The elastic scattering angular distributions of weakly bound nucleus$^{8}$Li on $^{7}$Li, $^{9}$Be, $^{12}$C, $^{13}$C, $^{14}$N,$^{27}$Al, $^{51}$V, $^{58}$Ni, and $^{208}$Pb are analyzed atvarious incident energies. For this purpose, the real potential isgenerated for nine different density distributions of the $^{8}$Linucleus by using the double folding model within the optical model.The theoretical results are in good agreement with the experimentaldata. In our study, also, new and practical sets of imaginarypotentials for the investigated densities are derived.


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