1,720,989 research outputs found
Stability of strange quark matter: MIT bag versus Color Dielectric Model
No full textWe discuss the properties of strange matter, in particular the minimum of the energy per baryon number as a function of the strangeness fraction. We utilize both the MIT bag model and the color dielectric model and compare the energy per baryon with the masses of hyperons having the corresponding strangeness fraction, which are coherently calculated within both models. We also take into account the perturbative exchange of gluons. The results obtained in the two approaches allow to discuss the stability of strangelets. While the MIT bag model and the double minimum version of the color dielectric model allow the existence of strangelets, the single minimum version of the color dielectric model excludes this possibility
Non-extensive statistics, fluctuations and correlations in high-energy nuclear collisions
No full textStarting from the experimental evidence that high-energy nucleus-nucleus collisions cannot be described in terms of superpositions of elementary nucleon-nucleon interactions, we analyze the possibility that memory effects and long-range forces imply a non-extensive statistical regime during high-energy heavy-ion collisions. The relevance of these statistical effects and their compatibility with the available experimental data are discussed. In particular, we show that theoretical estimates obtained in the framework of the generalized non-extensive thermostatistics, can reproduce the shape of the pion transverse mass spectrum and explain the different physical origin of the transverse momentum correlation function of the pions emitted during the central Pb + Pb and during the p +p collisions at 158 GeV
Response functions of asymmetric nuclear-matter.
No full textWe consider the spin-isospin response of asymmetric nuclear matter. The associated free and RPA polarization propagators, relative to isospin-flipping operators, are analytically evaluated and the new features with respect to the symmetric matter are pointed out. We suggest the relevance of neutron excess for charge exchange reactions in the region of the quasi-elastic peak
Non-extensive statistical effects in high-energy collisions
Full text linkFollowing the basic prescriptions of the relativistic Tsallis’ non-extensive thermostatistics, we investigate from a phenomenological point of view the relevance of non-extensive statistical effects on relativistic heavy-ion collisions observables, such as rapidity spectra of the net proton production, transverse momentum distributions and transverse momentum fluctuations. Moreover, we study the nuclear and the subnuclear equation of state, investigating the critical densities of a phase transition to a hadron-quark-gluon mixed phase by requiring the Gibbs conditions on the global conservation of the electric and the baryon charges. The relevance of small deviations from the standard extensive statistics is studied in the context of intermediate- and high-energy heavy-ion collisions
From nucleon-nucleon interaction to nuclear structure
No full textEdited by A. Molinari, L. Riccati, W. M. Alberico and M. Morando (IOS Press, Amsterdam, 2003
FROM NUCLEON-NUCLEON INTERACTION TO NUCLEAR STRUCTURE
No full textEdited by A. Molinari, L. Riccati, W. M. Alberico and M. Morando (IOS Press, Amsterdam, 2003
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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