Signatures of an $\alpha$ + core structure in $^{44}$Ti + $^{44}$Ti collisions at $\sqrt{s_{NN}}=5.02$ TeV by a multiphase transport model

Abstract

It is important to understand whether $\alpha$-clustering structures can leave traces in ultra-relativistic heavy ion collisions. Using the modified AMPT model, we simulate three $\alpha$ + core configurations of $^{44}$Ti in $^{44}$Ti+$^{44}$Ti collisions at $\sqrt{s_{NN}}=5.02$ TeV as well as other systems with Woods-Saxon structures. One of these configurations has no additional constraint, but the other two have the Mott density edge $r_{\mathrm{Mott}}$ set as either a lower or upper bound on the cluster position $r_{\alpha}$ to check the influence of $\alpha$ dissolution. This is the first time that the initial stage of the geometric properties in heavy-ion collisions has been configured using the traditional treatment of the nuclear structure. We compare the radial nucleon density, multiplicity distribution, transverse momentum spectra, eccentricity, triangularity, elliptic flow and triangular flow of these six systems. $\alpha$ + core structures can alter all these observations especially in the most-central collisions, among which elliptic flow is the most hopeful as a probe of such structures.