Journal of Physics G-nuclear and Particle Physics, 2009
We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) ... more We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) model of many-body field theory describing behavior of strongly interacting matter. It is based on the nonextensive generalization of the Boltzmann-Gibbs (BG) statistical mechanics used in NJL model, which was taken in the form proposed by Tsallis and characterized by a dimensionless nonextensivity parameter q (for q -> 1 one recovers the usual BG case). This is a new phenomenological parameter of the model which accounts summarily for all possible (so far unspecified) effects leading to departure from the conditions required by the usual BG approach to be fully applicable. It turns out that temperature dependencies of chiral symmetry restoration, masses of pion and sigma meson and characteristic features of spinodal decomposition are sensitive to the departures from the usual BG case.
The critical phenomena in strongly interaction matter are generally investigated using the mean-f... more The critical phenomena in strongly interaction matter are generally investigated using the mean-field model and are characterized by well defined critical exponents. However, such models provide only average properties of the corresponding order parameters and neglect altogether their possible fluctuations. Also the possible long range effect are neglected in the mean field approach. Here we investigate the critical behavior in the nonextensive version of the Nambu Jona-Lasinio model (NJL). It allows to account for such effects in a phenomenological way by means of a single parameter $q$, the nonextensivity parameter. In particular, we show how the nonextensive statistics influence the region of the critical temperature and chemical potential in the NJL mean field approach.
International Journal of Modern Physics E-nuclear Physics, 2000
Based on the relativistic mean field model of nuclear matter with scalar and vector components, a... more Based on the relativistic mean field model of nuclear matter with scalar and vector components, a convolution model of deeply inelastic electron-nucleus scattering has been developed. The influence of the scalar potential changes the nucleon structure function inside the nucleus and ensures agreement with the experiment in the Björken x>0.2. The Sum Rules are discussed. The role of the relativistic scalar and vector nuclear potential in the nucleus is shown.
The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions... more The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions are presented. They indicate --- together with the observed properties of Σ atoms --- that the Σ single particle potential VΣ is repulsive inside nuclei and has a shallow attractive pocket at the nuclear surface. This conclusion is consistent with the Nijmegen model F of the hyperon--nucleon interaction. It is demonstrated how the strong-interaction shifts and widths measured in Σ atoms may be used to obtain information on the nucleon density distributions.
Journal of Physics G-nuclear and Particle Physics, 2009
We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) ... more We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) model of many-body field theory describing behavior of strongly interacting matter. It is based on the nonextensive generalization of the Boltzmann-Gibbs (BG) statistical mechanics used in NJL model, which was taken in the form proposed by Tsallis and characterized by a dimensionless nonextensivity parameter q (for q -> 1 one recovers the usual BG case). This is a new phenomenological parameter of the model which accounts summarily for all possible (so far unspecified) effects leading to departure from the conditions required by the usual BG approach to be fully applicable. It turns out that temperature dependencies of chiral symmetry restoration, masses of pion and sigma meson and characteristic features of spinodal decomposition are sensitive to the departures from the usual BG case.
The critical phenomena in strongly interaction matter are generally investigated using the mean-f... more The critical phenomena in strongly interaction matter are generally investigated using the mean-field model and are characterized by well defined critical exponents. However, such models provide only average properties of the corresponding order parameters and neglect altogether their possible fluctuations. Also the possible long range effect are neglected in the mean field approach. Here we investigate the critical behavior in the nonextensive version of the Nambu Jona-Lasinio model (NJL). It allows to account for such effects in a phenomenological way by means of a single parameter $q$, the nonextensivity parameter. In particular, we show how the nonextensive statistics influence the region of the critical temperature and chemical potential in the NJL mean field approach.
International Journal of Modern Physics E-nuclear Physics, 2000
Based on the relativistic mean field model of nuclear matter with scalar and vector components, a... more Based on the relativistic mean field model of nuclear matter with scalar and vector components, a convolution model of deeply inelastic electron-nucleus scattering has been developed. The influence of the scalar potential changes the nucleon structure function inside the nucleus and ensures agreement with the experiment in the Björken x>0.2. The Sum Rules are discussed. The role of the relativistic scalar and vector nuclear potential in the nucleus is shown.
The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions... more The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions are presented. They indicate --- together with the observed properties of Σ atoms --- that the Σ single particle potential VΣ is repulsive inside nuclei and has a shallow attractive pocket at the nuclear surface. This conclusion is consistent with the Nijmegen model F of the hyperon--nucleon interaction. It is demonstrated how the strong-interaction shifts and widths measured in Σ atoms may be used to obtain information on the nucleon density distributions.
A simple theory of the interaction potential between heavy ions V, based on the local density app... more A simple theory of the interaction potential between heavy ions V, based on the local density approach and the frozen density model, is applied to a number of pairs of nuclei with neutron excess. The energy density needed for calculating V is expressed in a simple way through the equilibrium properties of nuclear matter, a phenomenological density gradient term, and nucleon density distributions in the two colliding nuclei. The Coulomb barrier in the calculated potential compares favorably with other estimates.
It is shown that among four models of the Nijmegen baryon--baryon interaction, only model F is co... more It is shown that among four models of the Nijmegen baryon--baryon interaction, only model F is consistent both with the analysis of Σ - atoms and (K-,π ) reactions. Simple estimates of the strong-interaction shifts and widths of the lowest observed levels of Σ - atoms are applied for model F with satisfying results. It is concluded that model F is favored as a realistic representation of the Σ N interaction.
Pion spectra from (K-,π+) reactions on 16O and 9Be targets in the region of Σ production are anal... more Pion spectra from (K-,π+) reactions on 16O and 9Be targets in the region of Σ production are analyzed in impulse approximation for different strengths of the Σ single particle potential. It is concluded that this potential is repulsive. It is pointed out that among the Nijmegen models of the hyperon--nucleon interaction only model F is compatible with this conclusion.
International Journal of Modern Physics E-nuclear Physics, 2007
The recently measured kaon spectrum from (π-, K+) reaction on 28Si target in the region of Σ prod... more The recently measured kaon spectrum from (π-, K+) reaction on 28Si target in the region of Σ production is analyzed in impulse approximation for different strengths of the Σ single particle nuclear potential UΣ = VΣ + iWΣ. The comparison with the measured kaon spectrum leads to the conclusion that the potential VΣ inside the nuclear core is strongly repulsive. A comparison with other estimates of the strength of VΣ is presented.
We calculate in the impulse approximation the kaon spectrum from the (π-,K+) reaction on Si28. Th... more We calculate in the impulse approximation the kaon spectrum from the (π-,K+) reaction on Si28. The strength VΣ of the real part of the single particle potential of the Σ hyperons produced in the reaction is obtained from the Nijmegen model F of the baryon-baryon interaction, and the strength WΣ of the imaginary (absorptive) part is determined by the ΣN cross sections for the ΣΛ conversion and also for the elastic ΣN scattering (this elastic scattering introduces a strong dependence of WΣ on the Σ momentum). The momentum dependence of VΣ is also considered. Our calculated inclusive kaon spectrum agrees reasonably with the spectrum measured at KEK. The strengths of the real and absorptive Σ potentials used in the present calculation are compatible with these strengths determined in the analyses of Σ atoms and of the strangeness exchange reactions.
Journal of Physics G-nuclear and Particle Physics, 2009
We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) ... more We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) model of many-body field theory describing behavior of strongly interacting matter. It is based on the nonextensive generalization of the Boltzmann-Gibbs (BG) statistical mechanics used in NJL model, which was taken in the form proposed by Tsallis and characterized by a dimensionless nonextensivity parameter q (for q -> 1 one recovers the usual BG case). This is a new phenomenological parameter of the model which accounts summarily for all possible (so far unspecified) effects leading to departure from the conditions required by the usual BG approach to be fully applicable. It turns out that temperature dependencies of chiral symmetry restoration, masses of pion and sigma meson and characteristic features of spinodal decomposition are sensitive to the departures from the usual BG case.
The critical phenomena in strongly interaction matter are generally investigated using the mean-f... more The critical phenomena in strongly interaction matter are generally investigated using the mean-field model and are characterized by well defined critical exponents. However, such models provide only average properties of the corresponding order parameters and neglect altogether their possible fluctuations. Also the possible long range effect are neglected in the mean field approach. Here we investigate the critical behavior in the nonextensive version of the Nambu Jona-Lasinio model (NJL). It allows to account for such effects in a phenomenological way by means of a single parameter $q$, the nonextensivity parameter. In particular, we show how the nonextensive statistics influence the region of the critical temperature and chemical potential in the NJL mean field approach.
International Journal of Modern Physics E-nuclear Physics, 2000
Based on the relativistic mean field model of nuclear matter with scalar and vector components, a... more Based on the relativistic mean field model of nuclear matter with scalar and vector components, a convolution model of deeply inelastic electron-nucleus scattering has been developed. The influence of the scalar potential changes the nucleon structure function inside the nucleus and ensures agreement with the experiment in the Björken x>0.2. The Sum Rules are discussed. The role of the relativistic scalar and vector nuclear potential in the nucleus is shown.
The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions... more The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions are presented. They indicate --- together with the observed properties of Σ atoms --- that the Σ single particle potential VΣ is repulsive inside nuclei and has a shallow attractive pocket at the nuclear surface. This conclusion is consistent with the Nijmegen model F of the hyperon--nucleon interaction. It is demonstrated how the strong-interaction shifts and widths measured in Σ atoms may be used to obtain information on the nucleon density distributions.
Journal of Physics G-nuclear and Particle Physics, 2009
We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) ... more We present a nonextensive version of the recently discussed QCD-based Nambu - Jona-Lasinio (NJL) model of many-body field theory describing behavior of strongly interacting matter. It is based on the nonextensive generalization of the Boltzmann-Gibbs (BG) statistical mechanics used in NJL model, which was taken in the form proposed by Tsallis and characterized by a dimensionless nonextensivity parameter q (for q -> 1 one recovers the usual BG case). This is a new phenomenological parameter of the model which accounts summarily for all possible (so far unspecified) effects leading to departure from the conditions required by the usual BG approach to be fully applicable. It turns out that temperature dependencies of chiral symmetry restoration, masses of pion and sigma meson and characteristic features of spinodal decomposition are sensitive to the departures from the usual BG case.
The critical phenomena in strongly interaction matter are generally investigated using the mean-f... more The critical phenomena in strongly interaction matter are generally investigated using the mean-field model and are characterized by well defined critical exponents. However, such models provide only average properties of the corresponding order parameters and neglect altogether their possible fluctuations. Also the possible long range effect are neglected in the mean field approach. Here we investigate the critical behavior in the nonextensive version of the Nambu Jona-Lasinio model (NJL). It allows to account for such effects in a phenomenological way by means of a single parameter $q$, the nonextensivity parameter. In particular, we show how the nonextensive statistics influence the region of the critical temperature and chemical potential in the NJL mean field approach.
International Journal of Modern Physics E-nuclear Physics, 2000
Based on the relativistic mean field model of nuclear matter with scalar and vector components, a... more Based on the relativistic mean field model of nuclear matter with scalar and vector components, a convolution model of deeply inelastic electron-nucleus scattering has been developed. The influence of the scalar potential changes the nucleon structure function inside the nucleus and ensures agreement with the experiment in the Björken x>0.2. The Sum Rules are discussed. The role of the relativistic scalar and vector nuclear potential in the nucleus is shown.
The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions... more The analyses of the strangeness exchange (K-,π ) and the associated production (π -,K+) reactions are presented. They indicate --- together with the observed properties of Σ atoms --- that the Σ single particle potential VΣ is repulsive inside nuclei and has a shallow attractive pocket at the nuclear surface. This conclusion is consistent with the Nijmegen model F of the hyperon--nucleon interaction. It is demonstrated how the strong-interaction shifts and widths measured in Σ atoms may be used to obtain information on the nucleon density distributions.
A simple theory of the interaction potential between heavy ions V, based on the local density app... more A simple theory of the interaction potential between heavy ions V, based on the local density approach and the frozen density model, is applied to a number of pairs of nuclei with neutron excess. The energy density needed for calculating V is expressed in a simple way through the equilibrium properties of nuclear matter, a phenomenological density gradient term, and nucleon density distributions in the two colliding nuclei. The Coulomb barrier in the calculated potential compares favorably with other estimates.
It is shown that among four models of the Nijmegen baryon--baryon interaction, only model F is co... more It is shown that among four models of the Nijmegen baryon--baryon interaction, only model F is consistent both with the analysis of Σ - atoms and (K-,π ) reactions. Simple estimates of the strong-interaction shifts and widths of the lowest observed levels of Σ - atoms are applied for model F with satisfying results. It is concluded that model F is favored as a realistic representation of the Σ N interaction.
Pion spectra from (K-,π+) reactions on 16O and 9Be targets in the region of Σ production are anal... more Pion spectra from (K-,π+) reactions on 16O and 9Be targets in the region of Σ production are analyzed in impulse approximation for different strengths of the Σ single particle potential. It is concluded that this potential is repulsive. It is pointed out that among the Nijmegen models of the hyperon--nucleon interaction only model F is compatible with this conclusion.
International Journal of Modern Physics E-nuclear Physics, 2007
The recently measured kaon spectrum from (π-, K+) reaction on 28Si target in the region of Σ prod... more The recently measured kaon spectrum from (π-, K+) reaction on 28Si target in the region of Σ production is analyzed in impulse approximation for different strengths of the Σ single particle nuclear potential UΣ = VΣ + iWΣ. The comparison with the measured kaon spectrum leads to the conclusion that the potential VΣ inside the nuclear core is strongly repulsive. A comparison with other estimates of the strength of VΣ is presented.
We calculate in the impulse approximation the kaon spectrum from the (π-,K+) reaction on Si28. Th... more We calculate in the impulse approximation the kaon spectrum from the (π-,K+) reaction on Si28. The strength VΣ of the real part of the single particle potential of the Σ hyperons produced in the reaction is obtained from the Nijmegen model F of the baryon-baryon interaction, and the strength WΣ of the imaginary (absorptive) part is determined by the ΣN cross sections for the ΣΛ conversion and also for the elastic ΣN scattering (this elastic scattering introduces a strong dependence of WΣ on the Σ momentum). The momentum dependence of VΣ is also considered. Our calculated inclusive kaon spectrum agrees reasonably with the spectrum measured at KEK. The strengths of the real and absorptive Σ potentials used in the present calculation are compatible with these strengths determined in the analyses of Σ atoms and of the strangeness exchange reactions.
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