Department of Physics, Graduate School of Science
Quark” is one of elementary particles and a fundamental constituent of matter. Normally, since quarks are confined within nucleons (protons and neutrons), their presence are never observed. However, when the temperature and /or density of matter reaches 1 to 100 trillion times that of normally found around us, quarks can behave freely because they are released from nucleons. I am studying the "phase transition" of “quark matter” composed of quarks under such extreme conditions.
In dense quark matter, it has been theoretically predicted that a color superconducting state will be realized. However, this state has never been observed experimentally. Since the states may be realized in a center of a neutron star, the further understanding about the color superconductivity is expected to lead to advances not only in nuclear physics, but also in astrophysics.
I focus on "the heavy-ion collision experiment", which is only an experiment that can probe the phase structure of quark matter on earth, and consider “dileptons” (electron, muon, etc.), which are observables in their experiments. Then, I explore the possibility of experimental observation of the color superconducting state through the theoretical analysis of dilepton production due to the phase transition of the color superconductivity.