Speaker
Description
We explore the equation of state (EOS) of dense nuclear matter using central collisions of deformed nuclei, focusing on tip–tip collisions. In collisions of strongly deformed nuclei such as Er, geometric asymmetry remains even in central events, resulting in a finite elliptic flow. Because flow observables are sensitive to the EOS, selecting specific collision geometries can provide information on the high-density EOS. In addition, tip–tip central collisions avoid the spectator-shadowing effect that often obscures particle emission from the high-density region in low-energy nuclear collisions. First, we analyze high-energy nuclear collisions, where lattice-QCD-based EOSs are applicable, using relativistic viscous hydrodynamics. The deformation dependence of the flow coefficients in tip–tip and body–body collisions is studied to determine nuclear deformation parameters. Next, low-energy collisions are investigated using the JAM transport model. The results indicate stronger stopping and enhanced midrapidity proton production in tip–tip collisions, while characteristic differences in v1 and v2 reflect the EOS dependence.