Heavy Ion Collisions and the role of the strange particle production

Full text: High energy physics are studied using the relativistic heavy ion collisions where a state of high temperature and energy density can be created. The conditions reached in these collisions are similar to those at early universe formation. The nuclear matter exhibits a phase transition from hadronic state to deconfined state of quarks and gluons. With this purpose, the Relativistic Heavy Ion Collider (RHIC) was built at the Brookhaven National Laboratory, USA. Since 2000, the RHIC is in operation and has allowed the collisions of heavy nuclei from different systems, such as Au + Au, Cu + Cu, d + Au as well as p + p for various center of mass energies (7.7 to 200 GeV ). One of the experiments located at RHIC is the Solenoidal Tracker at RHIC (STAR). The main physics goal is to study the formation and characteristics of the state of deconfined quarks and gluons, called quark gluon plasma (QGP). The STAR experiment has a complex set of detectors that is capable of measuring many different observables from an event. Charged particles can be identified using ionization energy loss and time of flight techniques. The measurements of strange particles are a vital tool for the study of QGP formation. For more than 20 years, the strangeness enhancement has been proposed as one of the possible signatures of the QGP. Up to date, there are many experimental results showing the enhancement of strange particles, such as Λ, Ξ, Ω and φ from different energies in heavy ion collisions when compared to p + p. In this work, we will present the main concept of heavy ion collisions as well as some important results for strange particle production. (author)