Abstract
This thesis contains a semi-phenomenological study of the Nucleon-Antinucleon interaction at low energy, and in particular of the annihilation of Proton-Antiproton system into two charged pions or kaons. This annihilation reaction is calculated within the DWBA (Distorted-Wave Born-Approximation) formalism: the transition into two mesons is treated as perturbation around the solution computed out of the whole interaction, including elastic forces and absorption. We first review the optical-potential models which describe the Nucleon-Antinucleon scattering in term of meson exchange supplemented by a complex core to simulate the effects of absorption. Those optical potentials provide the initial state for the annihilation reactions. The transition itself is described by mean of two models, a local one and a separable one. As for the local model, the results are generally in good agreement with experimental data, especially for the analyzing power, but the backward hemisphere for annihilation into two kaons cannot be reproduced. The separable model restricts the transition to S and P waves only, but leads rather naturally to an enhancement of the P wave with respect to the S wave, improving the global description of the angular distribution. This P to S ratio is intimately connected to the relative weight of quark
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Citation Formats
Elchikh, M.
Contribution at the study of nucleon-antinucleon interaction at low energy and at the proton-antiproton transition in two pions or kaons; Contribution a l`etude de l`interaction nucleon-antinucleon a basse energie et a la transition proton-antiproton en deux pions ou deux kaons.
France: N. p.,
1992.
Web.
Elchikh, M.
Contribution at the study of nucleon-antinucleon interaction at low energy and at the proton-antiproton transition in two pions or kaons; Contribution a l`etude de l`interaction nucleon-antinucleon a basse energie et a la transition proton-antiproton en deux pions ou deux kaons.
France.
Elchikh, M.
1992.
"Contribution at the study of nucleon-antinucleon interaction at low energy and at the proton-antiproton transition in two pions or kaons; Contribution a l`etude de l`interaction nucleon-antinucleon a basse energie et a la transition proton-antiproton en deux pions ou deux kaons."
France.
@misc{etde_10153991,
title = {Contribution at the study of nucleon-antinucleon interaction at low energy and at the proton-antiproton transition in two pions or kaons; Contribution a l`etude de l`interaction nucleon-antinucleon a basse energie et a la transition proton-antiproton en deux pions ou deux kaons}
author = {Elchikh, M}
abstractNote = {This thesis contains a semi-phenomenological study of the Nucleon-Antinucleon interaction at low energy, and in particular of the annihilation of Proton-Antiproton system into two charged pions or kaons. This annihilation reaction is calculated within the DWBA (Distorted-Wave Born-Approximation) formalism: the transition into two mesons is treated as perturbation around the solution computed out of the whole interaction, including elastic forces and absorption. We first review the optical-potential models which describe the Nucleon-Antinucleon scattering in term of meson exchange supplemented by a complex core to simulate the effects of absorption. Those optical potentials provide the initial state for the annihilation reactions. The transition itself is described by mean of two models, a local one and a separable one. As for the local model, the results are generally in good agreement with experimental data, especially for the analyzing power, but the backward hemisphere for annihilation into two kaons cannot be reproduced. The separable model restricts the transition to S and P waves only, but leads rather naturally to an enhancement of the P wave with respect to the S wave, improving the global description of the angular distribution. This P to S ratio is intimately connected to the relative weight of quark annihilation and quark rearrangement diagrams. The true dynamics of those annihilation reactions presumably mixes our two models, with a transition operator being almost local in the high partial waves and nearly separable for the S and the P waves.}
place = {France}
year = {1992}
month = {Oct}
}
title = {Contribution at the study of nucleon-antinucleon interaction at low energy and at the proton-antiproton transition in two pions or kaons; Contribution a l`etude de l`interaction nucleon-antinucleon a basse energie et a la transition proton-antiproton en deux pions ou deux kaons}
author = {Elchikh, M}
abstractNote = {This thesis contains a semi-phenomenological study of the Nucleon-Antinucleon interaction at low energy, and in particular of the annihilation of Proton-Antiproton system into two charged pions or kaons. This annihilation reaction is calculated within the DWBA (Distorted-Wave Born-Approximation) formalism: the transition into two mesons is treated as perturbation around the solution computed out of the whole interaction, including elastic forces and absorption. We first review the optical-potential models which describe the Nucleon-Antinucleon scattering in term of meson exchange supplemented by a complex core to simulate the effects of absorption. Those optical potentials provide the initial state for the annihilation reactions. The transition itself is described by mean of two models, a local one and a separable one. As for the local model, the results are generally in good agreement with experimental data, especially for the analyzing power, but the backward hemisphere for annihilation into two kaons cannot be reproduced. The separable model restricts the transition to S and P waves only, but leads rather naturally to an enhancement of the P wave with respect to the S wave, improving the global description of the angular distribution. This P to S ratio is intimately connected to the relative weight of quark annihilation and quark rearrangement diagrams. The true dynamics of those annihilation reactions presumably mixes our two models, with a transition operator being almost local in the high partial waves and nearly separable for the S and the P waves.}
place = {France}
year = {1992}
month = {Oct}
}