EuNPC2015

phi(1020) mesons emitted from Ni+Ni and Al+Al collisions at the beam kinetic energy of 1.9A GeV were investigated by the FOPI Collaboration [1,2]. Significantly larger data sample was obtained compared to our previous measurements [3]. Basic parameters of phi(1020) emission were obtained from kinetic energy distribution. Our results are close to that obtained by the HADES Collaboration at similar beam energy [4]. As a result of the dominant phi meson decay to K+K- pair [5], the kinematic spectra of K- receive a considerable feeding. We show that this contribution clearly softens the K- spectra. In consequence, a considerable part of the gap between the inverse slopes of K- and K+, that was observed for most of the colliding systems at similar beam energies [6], can be explained by the influence of phi mesons to the K- spectra. (K. Piasecki for the FOPI Collaboration) [1] K. Piasecki et al. (FOPI Collaboration), arXiv:1412.4493, submitted to Phys. Rev. C. [2] P. Gasik (FOPI Collaboration), Ph.D. Thesis, University of Warsaw (unpublished). [3] A. Mangiarotti et al. (FOPI Collaboration), Nucl. Phys. A 714, 89 (2003). [4] G. Agakishiev et al. (HADES Collaboration), Phys. Rev. C 80, 025209 (2009). [5] K.A. Olive et al. (Particle Data Group), Chin. Phys. C, 38, 090001 (2014). [6] A. Foerster et al. (KaoS Collaboration), Phys. Rev. C 75, 024906 (2007).