Predictions on global properties in O+O collisions at the Large Hadron Collider using a multi-phase transport model

TL;DR

This study predicts global properties of O+O collisions at 7 TeV using a multi-phase transport model, exploring system size effects, nuclear density profiles, and nuclear structure on collision outcomes at the LHC.

Contribution

It provides the first detailed predictions of global properties in O+O collisions at the LHC, including effects of nuclear density profiles and clustering structures.

Findings

Charged-particle multiplicity increases significantly in central collisions with harmonic oscillator profile.

Bjorken energy density shows notable increase in central collisions for harmonic oscillator profile.

Results suggest minimal dependence of most global properties on nuclear density profile variations.

Abstract

Oxygen ($^{16}$O) ions are planned to be injected at the Large Hadron Collider (LHC) in its next runs, and a day of physics run is anticipated for O+O collisions at $\sqrt{s_{\rm{NN}}}$ = 7 TeV. As the system size of O+O collisions has the final state multiplicity overlap with those produced in pp, p+Pb and Pb+Pb collisions, the study of global properties in O+O collisions may provide a deeper insight into the heavy-ion-like behavior observed in small collision systems and its similarities/differences with a larger system like Pb+Pb collisions. In the present work, we report the predictions for global properties in O+O collisions at $\sqrt{s_{\rm{NN}}}$ = 7 TeV using a multi-phase transport model (AMPT). We report the mid-rapidity charged-particle multiplicity, transverse mass, Bjorken energy density, pseudo-rapidity distributions, squared speed of sound, transverse momentum ($p_{\rm T}$) spectra, the kinetic freeze-out parameters, and $p_{\rm T}$-differential particle ratio as a function of collision centrality. Further, we have studied the transverse momentum-dependent elliptic flow of charged particles. The results are shown for Woods-Saxon and harmonic oscillator nuclear density profiles. In addition, we have compared the results with an $\alpha$-clustered structure incorporated inside the oxygen nucleus. Average charged-particle multiplicity and the Bjorken energy density show a significant increase in most central collisions for the harmonic oscillator density profile, while other global properties show less dependence on the density profiles considered in this work. The results from the $\alpha$-clustered structure incorporated inside the oxygen nucleus show similar initial energy density and final charged-particle multiplicity as observed for the harmonic oscillator density profile.