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ID: 544582.0, MPI für Physik / MPI für Physik
Recent results on spectra and yields from NA49
Authors:
Date of Publication (YYYY-MM-DD):2003
Title of Journal:Nuclear Physics A
Journal Abbrev.:Nucl.Phys.A
Issue / Number:715
Start Page:161
End Page:170
Audience:Not Specified
Intended Educational Use:No
Abstract / Description:The energy dependence of hadron production in central Pb+Pb collisions is presented and discussed. In particular, midrapidity $m_T$-spectra for $\pi^-$, $K^-$, $K^+$, $p$, $\bar{p}$, $d$, $\phi$, $\Lambda$ and $\bar{\Lambda}$ at 40, 80 and 158 $A$GeV are shown. In addition $\Xi$ and $\Omega$ spectra are available at 158 $A$GeV. The spectra allow to determine the thermal freeze-out temperature $T$ and the transverse flow velocity $\beta_T$ at the three energies. We do not observe a significant energy dependence of these parameters; furthermore there is no indication of early thermal freeze-out of $\Xi$ and $\Omega$ at 158 $A$GeV. Rapidity spectra for $\pi^-$, $K^-$, $K^+$ and $\phi$ at 40, 80 and 158 $A$GeV are shown, as well as first results on $\Omega$ rapidity distributions at 158 $A$GeV. The chemical freeze-out parameters $T$ and $\mu_B$ at the three energies are determined from the total yields. The parameters are close to the expected phase boundary in the SPS energy range and above. Using the total yields of kaons and lambdas, the energy dependence of the strangeness to pion ratio is discussed. A maximum in this ratio is found at 40 $A$GeV. This maximum could indicate the formation of deconfined matter at energies above 40 $A$GeV. A search for open charm in a large sample of 158 $A$GeV events is presented. No signal is observed. This result is compared to several model predictions.
Classification / Thesaurus:NA49
Comment of the Author/Creator:10 pages, 9 figures, Presented at Quark Matter 2002, Nantes, France
External Publication Status:published
Document Type:Conference-Paper
Communicated by:N.N.
Affiliations:
Identifiers:
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