| In the study of hot and dense nuclear matter, created in relativistic heavy-ion collisions, dileptons are considered as ideal penetrating probes as its are produced in whole evolution of the system and have very little interaction with quark medium. Therefore, it allows the study of the system throughout its space-time evolution. In the low mass range ($M_{ll}<1 .1$~gev/c$2$) the dominant source of dileptons originates from the decay of vector mesons which may see effects from chiral symmetry restoration. in the intermediate mass range ($1.1<3 .0 $~gev/c$2$) the main contributions to the mass spectrum are expected to originate from the thermal radiation of a quark-gluon plasma as well as the decays of charm mesons.
With the introduction of the Time-of-Flight detector, the STAR detector at
the Relativistic Heavy Ion Collider (RHIC) has been able to perform large acceptance, high purity electron identification. In this talk, we will present STAR's recent dielectron measurements in the low and intermediate mass range for RHIC beam energies ranging between 19.6 and 200~GeV. Compared to electrons, muon measurements have the advantage of reduced Bremsstrahlung radiation in the surrounding detector materials.With the upcoming detector upgrades, specifically the muon detector (MTD), STAR will be able to include such measurements in its (di-)lepton studies.We will discuss the future dilepton program at STAR and the physics cases for these upgrades.
|
