Small-x structure of oxygen and neon isotopes as seen by the Large Hadron Collider

¹ Department of Physics, University of Jyvaskyla, 40014, Finland
² Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120, Germany
³ Physics Department, Brookhaven National Laboratory, Bldg. 510A, Upton, NY 11973, USA
⁴ Fakultät für Physik, Universität Bielefeld, D-33615 Bielefeld, Germany

^* e-mail: prasingh@jyu.fi

Published online: 26 June 2024

Abstract

Results on collisions of ¹⁶O nuclei performed at the Relativistic Heavy Ion Collider (RHIC) have been presented for the first time at Quark Matter 2023 by the STAR collaboration. ¹⁶O+¹⁶O collisions are also expected to take place in the near future at the Large Hadron Collider (LHC) at much higher beam energies. We explore the potential of beam-energy-dependent studies for this system to probe small-x dynamics and QCD evolution. We perform 3 + 1D IP-Glasma simulations to predict the rapidity dependence of the initial geometry of light-ion collisions, focusing on ¹⁶O+¹⁶O and ²⁰Ne+²⁰Ne collisions at √S_NN = 70 GeV and 7 TeV. The choice of ²⁰Ne is motivated by its strongly elongated geometry, which may respond differently to the effect of the highenergy evolution compared to the more spherical ¹⁶O. We find that smearing induced by soft gluon production at high energy causes mild variations in the initial-state eccentricities as a function of the collision energy. These effects could be resolved in future experiments and deserve further investigation.