Abstract
In the present thesis the production of neutral mesons ({pi}{sup 0} and {eta} mesons) in the heavy ion reactions {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub lab}=1 GeV/u is treated. Especially the dependence of the cross sections and pion spectra on the total mass of the colliding systems is studied. From the measurement resuylted the total cross sections for the production of neutral pions and {eta}mesons. Under the assumption of an isotropic, thermal source from this the multiplicity of both kinds of mesons per reaction is determined. The concave shape of the pion spectra is discussed in a simple model as superposition of pions from the decay of the {Delta}, N1440, and N1535 resonances. Thereby the contributions of the baryons are determined, which are excited into resonances before the freezing out of the pions. For the {Delta}resonance this contribution amounts in all systems to 8-10%. The N1440 resonance is against the delta suppressed by the factor 3-5, whereby the contribution increases with the system mass. The {eta}/{pi}{sup 0} ratio amounts at E/A=1 GeV typically to 1.3%. From here a suppression of the N1535 resonance by the factor 80 against the delta results.
Citation Formats
Schwalb, O.
Mass dependence of the meson production in the systems {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub Lab}=1 GeV/u; Massenabhaengigkeit der Mesonenproduktion in den Systemen {sup 86}Kr+{sup nat}Zr und {sup 197}Au+{sup 197}Au bei E{sub Lab}=1 GeV/u.
Germany: N. p.,
1993.
Web.
Schwalb, O.
Mass dependence of the meson production in the systems {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub Lab}=1 GeV/u; Massenabhaengigkeit der Mesonenproduktion in den Systemen {sup 86}Kr+{sup nat}Zr und {sup 197}Au+{sup 197}Au bei E{sub Lab}=1 GeV/u.
Germany.
Schwalb, O.
1993.
"Mass dependence of the meson production in the systems {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub Lab}=1 GeV/u; Massenabhaengigkeit der Mesonenproduktion in den Systemen {sup 86}Kr+{sup nat}Zr und {sup 197}Au+{sup 197}Au bei E{sub Lab}=1 GeV/u."
Germany.
@misc{etde_10121515,
title = {Mass dependence of the meson production in the systems {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub Lab}=1 GeV/u; Massenabhaengigkeit der Mesonenproduktion in den Systemen {sup 86}Kr+{sup nat}Zr und {sup 197}Au+{sup 197}Au bei E{sub Lab}=1 GeV/u}
author = {Schwalb, O}
abstractNote = {In the present thesis the production of neutral mesons ({pi}{sup 0} and {eta} mesons) in the heavy ion reactions {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub lab}=1 GeV/u is treated. Especially the dependence of the cross sections and pion spectra on the total mass of the colliding systems is studied. From the measurement resuylted the total cross sections for the production of neutral pions and {eta}mesons. Under the assumption of an isotropic, thermal source from this the multiplicity of both kinds of mesons per reaction is determined. The concave shape of the pion spectra is discussed in a simple model as superposition of pions from the decay of the {Delta}, N1440, and N1535 resonances. Thereby the contributions of the baryons are determined, which are excited into resonances before the freezing out of the pions. For the {Delta}resonance this contribution amounts in all systems to 8-10%. The N1440 resonance is against the delta suppressed by the factor 3-5, whereby the contribution increases with the system mass. The {eta}/{pi}{sup 0} ratio amounts at E/A=1 GeV typically to 1.3%. From here a suppression of the N1535 resonance by the factor 80 against the delta results.}
place = {Germany}
year = {1993}
month = {Oct}
}
title = {Mass dependence of the meson production in the systems {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub Lab}=1 GeV/u; Massenabhaengigkeit der Mesonenproduktion in den Systemen {sup 86}Kr+{sup nat}Zr und {sup 197}Au+{sup 197}Au bei E{sub Lab}=1 GeV/u}
author = {Schwalb, O}
abstractNote = {In the present thesis the production of neutral mesons ({pi}{sup 0} and {eta} mesons) in the heavy ion reactions {sup 86}Kr+{sup nat}Zr and {sup 197}Au+{sup 197}Au at E{sub lab}=1 GeV/u is treated. Especially the dependence of the cross sections and pion spectra on the total mass of the colliding systems is studied. From the measurement resuylted the total cross sections for the production of neutral pions and {eta}mesons. Under the assumption of an isotropic, thermal source from this the multiplicity of both kinds of mesons per reaction is determined. The concave shape of the pion spectra is discussed in a simple model as superposition of pions from the decay of the {Delta}, N1440, and N1535 resonances. Thereby the contributions of the baryons are determined, which are excited into resonances before the freezing out of the pions. For the {Delta}resonance this contribution amounts in all systems to 8-10%. The N1440 resonance is against the delta suppressed by the factor 3-5, whereby the contribution increases with the system mass. The {eta}/{pi}{sup 0} ratio amounts at E/A=1 GeV typically to 1.3%. From here a suppression of the N1535 resonance by the factor 80 against the delta results.}
place = {Germany}
year = {1993}
month = {Oct}
}