7 research outputs found
Analysis of kaon spectra at SIS energies - what remains from the KN potential
We study the reaction Au+Au at 1.48 AGeV and analyze the influence of the KN
optical potential on cm spectra and azimuthal distributions at mid-rapidity. We
find a significant change of the yields but only slight changes in the shapes
of the distributions when turning off the optical potential. However, the
spectra show contributions from different reaction times, where early kaons
contribute stronger to higher momenta and late kaons to lower momenta.
Azimuthal distributions of the kaons at mid-rapidity show a strong centrality
dependence. Their shape is influenced by the KN optical potential as well as by
re-scattering.Comment: SQM 2003 proceedings, 4 figures, 6 page
Kaon and Antikaon Production in Heavy Ion Collisions at 1.5 AGeV
At the Kaon Spectrometer KaoS at SIS, GSI the production of kaons and
antikaons in heavy ion reactions at a beam energy of 1.5 AGeV has been measured
for the collision systems Ni+Ni and Au+Au. The K-/K+ ratio is found to be
constant for both systems and as a function of impact parameter but the slopes
of K+ and K- spectra differ for all impact parameters. Furthermore the
respective polar angle distributions will be presented as a function of
centrality.Comment: 4 pages, 4 figures, SQM2001 in Frankfurt, Sept.2001, submitted to
Journal of Physics
Hyperon production in Ar+KCl collisions at 1.76A GeV
We present transverse momentum spectra, rapidity distribution and
multiplicity of Lambda-hyperons measured with the HADES spectrometer in the
reaction Ar(1.76A GeV)+KCl. The yield of Xi- is calculated from our previously
reported Xi-/(Lambda+Sigma0) ratio and compared to other strange particle
multiplicities. Employing a strangeness balance equation the multiplicities of
the yet unmeasured charged Sigma hyperons can be estimated. Finally a
statistical hadronization model is used to fit the yields of pi-, K+, K0s, K-,
phi, Lambda and Xi-. The resulting chemical freeze-out temperature of T=(76+-2)
MeV is compared to the measured slope parameters obtained from fits to the
transverse mass distributions of the particles