Strange meson production in Al+Al collisions at 1.9A GeV
nucl-ex
/ Authors
P. Gasik, K. Piasecki, N. Herrmann, Y. Leifels, T. Matulewicz, A. Andronic, R. Averbeck, V. Barret, Z. Basrak, N. Bastid
and 56 more authors
M. L. Benabderrahmane, M. Berger, P. Buehler, M. Cargnelli, R. Čaplar, P. Crochet, O. Czerwiakowa, I. Deppner, P. Dupieux, M. Dželalija, L. Fabbietti, Z. Fodor, I. Gašparić, Y. Grishkin, O. N. Hartmann, K. D. Hildenbrand, B. Hong, T. I. Kang, J. Kecskemeti, Y. J. Kim, M. Kirejczyk, M. Kiš, P. Koczon, R. Kotte
/ Abstract
The production of K$^+$, K$^-$ and $\varphi$(1020) mesons is studied in Al+Al collisions at a beam energy of 1.9A GeV which is close or below the production threshold in NN reactions. Inverse slopes, anisotropy parameters, and total emission yields of K$^{\pm}$ mesons are obtained. A comparison of the ratio of kinetic energy distributions of K$^-$ and K$^+$ mesons to the HSD transport model calculations suggests that the inclusion of the in-medium modifications of kaon properties is necessary to reproduce the ratio. The inverse slope and total yield of $φ$ mesons are deduced. The contribution to K$^-$ production from $φ$ meson decays is found to be [17 $\pm$ 3 (stat) $^{+2}_{-7}$ (syst)] %. The results are in line with previous K$^{\pm}$ and $φ$ data obtained for different colliding systems at similar incident beam energies.