Strangelets and Strange Quark Matter

As it has been discussed widely during this conference, strangeness opens a new dimensions to nuclear physics. Insofar, systems with strangeness number S = −1,−2 have been discussed. Here we want to examine the unknown domain of finite nuclear systems with S < −2. There have been speculations about the existence of finite systems of strange quark matter (strangelets) and strange hadronic matter. Here we will focus on the former objects and recent progress in this field [1] as the latter ones were discussed at the last hypernuclear meeting in detail [2]. How can one produce such strangeness-rich systems? Hadron beams enable only to explore systems up to S = −2. Nevertheless, relativistic truly heavy-ion collisions constitute a prolific source of strangeness as dozens of hyperons are produced on a single central event. In principle, strangelets can be produced via two different scenarios: by a coalescence of hyperons or by a distillation of a quark-gluon plasma. The coalescence model for strangelet production in heavy-ion collisions has been put forward by Carl Dover [3]. The formation of a quark-gluon plasma is not needed in this scenario. Hyperons coalesce during the late stage of the collision forming a doorway state for strangelet production. For example, the H dibaryon would be formed by the coalescence of two Λ’s or a Ξ with a nucleon which transform to a dibaryon with the same quantum numbers. The production rates are proportional to two penalty factors, one for adding a baryon number and the second one for adding one unit of strangeness to the clusters