STAR's measurement of energy and system size dependence of K/π fluctuations at RHIC

Strangeness enhancement has been predicted to be one of the signatures of the formation of the quark-gluon plasma (QGP) and event-by-event fluctuations of strangeness may reveal the nature of such a phase transition. We report results for K/pi fluctuations from Cu+Cu at root(NN)-N-S = 62.4 and 200 GeV and Au+Au collisions at root(NN)-N-S = 62.4, 130 and 200 GeV using the STAR detector at the relativistic heavy- ion collider. We compare our results with the results observed in central Pb+Pb collisions at SPS energies at root(NN)-N-S = 6.3, 7.6, 8.8, 12.3 and 17.3 GeV. We observe that the fluctuation strength measured at the highest SPS energy point by the NA49 Collaboration in Pb+Pb collisions is similar to our results in Cu+Cu and Au+Au collisions. We also compare our results with HIJING, a statistical hadronization model and a multi-phase transport model.