First evidence for different freeze-out conditions for kaons and antikaons observed in heavy-ion collisions

A. Foerster; F. Uhlig; I. Boettcher; M. Debowski; F. Dohrmann; E. Grosse; P. Koczon; B. Kohlmeyer; F. Laue; M. Menzel; L. Naumann; H. Oeschler; W. Scheinast; E. Schwab; P. Senger; Y. Shin; H. Stroebele; C. Sturm; G. Surowka; A. Wagner; W. Walus

doi:10.1103/physrevlett.91.152301

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First evidence for different freeze-out conditions for kaons and antikaons observed in heavy-ion collisions

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Abstract

Differential production cross sections of K- and K+ mesons have been measured in Ni+Ni and Au+Au collisions at a beam energy of 1.5 AGeV. The K-/K+ ratio is found to be nearly constant as a function of the collision centrality and system size. The spectral slopes and the polar emission pattern differ for K- and K+ mesons. These observations indicate that K+ mesons decouple earlier from the fireball than K- mesons.

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A. Foerster, F. Uhlig, I. Boettcher, M. Debowski, F. Dohrmann, E. Grosse, P. Koczon, B. Kohlmeyer, F. Laue, M. Menzel, L. Naumann, H. Oeschler, W. Scheinast, E. Schwab, P. Senger, Y. Shin, H. Stroebele, C. Sturm, G. Surowka, A. Wagner, W. Walus. 2003-09-29. First evidence for different freeze-out conditions for kaons and antikaons observed in heavy-ion collisions. https://doi.org/10.1103/physrevlett.91.152301

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