At extremely high temperature and energy density, the quarks and gluons form a novel state of matter called the Quark-Gluon Plasma (QGP). The QGP has been widely studied via relativistic heavy ion collisions in large collision systems like Au+Au and Pb+Pb. However, whether the QGP exists in small systems like p+Au, and the dependence of QGP production on the collision system size are still open questions. One way to study the QGP properties is by using proxies of high energy partons, which are created in the initial stages of the collisions, and fragment into hadrons in the final state. These partons lose energy while traveling through the QGP, which can be reflected via the modified hadron yields. By contrasting hadron spectra in p+p to those in A+A, we can determine the amount of medium modification, which informs us about the QGP properties. In this thesis, I report studies on charged hadron yields in Ru+Ru, Zr+Zr and p+Au collisions at 200 GeV with the STAR detector at RHIC, and their comparisons with the hadron yield in p+p collisions. The results are compared with previous measurements at STAR as well as theoretical models, and potential future measurements are discussed.
Advisor: Helen Caines