dorsal/arxiv
View SchemaReconstructing the Freeze-out State in Pb+Pb Collisions at 158 AGeV/c
| Authors | Boris Tomasik, Urs Achim Wiedemann, Ulrich Heinz |
|---|---|
| Categories | |
| ArXiv ID | nucl-th/9907096 |
| URL | https://arxiv.org/abs/nucl-th/9907096 |
| DOI | 10.1556/APH.17.2003.1.11 |
| Journal | Heavy Ion Phys.17:105-143,2003 |
Abstract
For a class of analytical parametrizations of the freeze-out state of relativistic heavy ion collisions, we perform a simultaneous analysis of the single-particle m_t-spectra and two-particle Bose-Einstein correlations measured in central Pb+Pb collisions at the CERN SPS. The analysis includes a full model parameter scan with chi^2 confidence levels. A comparison of different transverse density profiles for the particle emission region allows for a quantitative discussion of possible model dependencies of the results. Our fit results suggest a low thermal freeze-out temperature T approximately 95 +- 15 MeV and a large average transverse flow velocity of about 0.55c +- 0.07c. Moreover, the fit favours a box-shaped transverse density profile over a Gaussian one. We discuss the origins and the consequences of these results in detail. In order to reproduce the measured pion multiplicity our model requires a positive pion chemical potential. A study of the pion phase-space density indicates \mu_\pi approximately 60 MeV for T = 100 MeV.
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"abstract": "For a class of analytical parametrizations of the freeze-out state of\nrelativistic heavy ion collisions, we perform a simultaneous analysis of the\nsingle-particle m_t-spectra and two-particle Bose-Einstein correlations\nmeasured in central Pb+Pb collisions at the CERN SPS. The analysis includes a\nfull model parameter scan with chi^2 confidence levels. A comparison of\ndifferent transverse density profiles for the particle emission region allows\nfor a quantitative discussion of possible model dependencies of the results.\nOur fit results suggest a low thermal freeze-out temperature T approximately 95\n+- 15 MeV and a large average transverse flow velocity of about 0.55c +- 0.07c.\nMoreover, the fit favours a box-shaped transverse density profile over a\nGaussian one. We discuss the origins and the consequences of these results in\ndetail. In order to reproduce the measured pion multiplicity our model requires\na positive pion chemical potential. A study of the pion phase-space density\nindicates \\mu_\\pi approximately 60 MeV for T = 100 MeV.",
"arxiv_id": "nucl-th/9907096",
"authors": [
"Boris Tomasik",
"Urs Achim Wiedemann",
"Ulrich Heinz"
],
"categories": [
"nucl-th"
],
"doi": "10.1556/APH.17.2003.1.11",
"journal_ref": "Heavy Ion Phys.17:105-143,2003",
"title": "Reconstructing the Freeze-out State in Pb+Pb Collisions at 158 AGeV/c",
"url": "https://arxiv.org/abs/nucl-th/9907096"
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