@article{3074081,
    title = "Energy dependence of particle ratio fluctuations in central Pb+Pb collisions from sNN=6.3 to 17.3 GeV",
    author = "Alt, C. and Anticic, T. and Baatar, B. and Barna, D. and Bartke, J. and Betev, L. and Białkowska, H. and Blume, C. and Boimska, B. and Botje, M. and Bracinik, J. and Bramm, R. and Bunčcić, P. and Cerny, V. and Christakoglou, P. and Chvala, O. and Cramer, J.G. and Csató, P. and Dinkelaker, P. and Eckardt, V. and Flierl, D. and Fodor, Z. and Foka, P. and Friese, V. and Gál, J. and Gazdzicki, M. and Genchev, V. and Georgopoulos, G. and Gładysz, E. and Grebieszkow, K. and Hegyi, S. and Höhne, C. and Kadija, K. and Karev, A. and Kliemant, M. and Kniege, S. and Kolesnikov, V.I. and Kornas, E. and Korus, R. and Kowalski, M. and Kraus, I. and Kreps, M. and Kresan, D. and Van Leeuwen, M. and Lévai, P. and Litov, L. and Lungwitz, B. and Makariev, M. and Malakhov, A.I. and Mateev, M. and Melkumov, G.L. and Mischke, A. and Mitrovski, M. and Molnár, J. and Mrówczyński, St. and Nicolic, V. and Pálla, G. and Panagiotou, A.D. and Panayotov, D. and Petridis, A. and Pikna, M. and Prindle, D. and Pühlhofer, F. and Renfordt, R. and Roland, C. and Roland, G. and Rybczyński, M. and Rybicki, A. and Sandoval, A. and Schmitz, N. and Schuster, T. and Seyboth, P. and Siklér, F. and Sitar, B. and Skrzypczak, E. and Stefanek, G. and Stock, R. and Ströbele, H. and Susa, T. and Szentpétery, I. and Sziklai, J. and Szymanski, P. and Trubnikov, V. and Varga, D. and Vassiliou, M. and Veres, G.I. and Vesztergombi, G. and Vranić, D. and Wetzler, A. and Włodarczyk, Z. and Yoo, I.K.",
    journal = "PHYSICAL REVIEW C : NUCLEAR PHYSICS",
    year = "2009",
    volume = "79",
    number = "4",
    publisher = "American Physical Society",
    issn = "0556-2813",
    doi = "10.1103/PhysRevC.79.044910",
    abstract = "We present measurements of the energy dependence of event-by-event fluctuations in the K/π and (p+p̄)/π multiplicity ratios in heavy-ion collisions at the CERN SPS. The particle ratio fluctuations were obtained for central Pb+Pb collisions at five collision energies, sNN, between 6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics and detector resolution, we extract the strength of nonstatistical fluctuations at each energy. For the K/π ratio, larger fluctuations than expected for independent particle production are found at all collision energies. The fluctuations in the (p+p̄)/π ratio are smaller than expectations from independent particle production, indicating correlated pion and proton production from resonance decays. For both ratios, the deviation from purely statistical fluctuations shows an increase toward lower collision energies. The results are compared to transport model calculations, which fail to describe the energy dependence of the K/π ratio fluctuations. © 2009 The American Physical Society."
}