Does the suppression shown at LHC in O-O collisions follow the systematics obtained for A-A collisions ?

TL;DR

This work tests whether O-O collisions at $\sqrt{s_{NN}}=5.36$ TeV follow the suppression systematics established in heavier A-A systems, by comparing ALICE/CMS measurements of $R_{AA}$ for $\pi^0$ and the $R_{AA}^N$ ratio to prior A-A Trends as functions of $\langle N_{part} \rangle$ and $\langle dN_{ch}/d\eta \rangle$. Using Glauber MC estimates for $\langle N_{part} \rangle$ and $\langle N_{bin} \rangle$ and ALICE $\langle dN_{ch}/d\eta \rangle$ inputs, the O-O data align with the heavy-ion systematics, including the $R_{AA}$ vs $\langle N_{part} \rangle$ and $R_{AA}^N$ vs $\langle dN_{ch}/d\eta \rangle$ relationships. The analysis discusses energy-loss scaling via $S_{\perp}$ and the temperature dependence, showing that when folded into $\langle dN_{ch}/d\eta \rangle$, the energy dependence of suppression largely collapses, while geometric differences persist in some representations. Overall, the results support the notion that light heavy-ion collisions like O-O obey the same suppression systematics as heavier systems within current uncertainties, though more precise data are needed for definitive confirmation.

Abstract

In this letter we want to see to what extent recent experimental results obtained for $π^{0}$ suppression in O-O collisions at $\sqrt{s_{NN}}$=5.36 TeV fit into the systematics for much heavier systems. The systematics with which the comparison is made was published a few years ago \cite{Pet_1} in terms of charged particles suppression $R_{AA}$ as a function of $\langle N_{part} \rangle$ and $\langle dN_{ch}/dη\rangle$ and the newly introduced $R_{AA}^N=\frac{(\frac{d^{2}N}{dp_{T}dη}/\langle \frac{dN_{ch}}{dη}\rangle)^{cen}}{(\frac{d^2N}{dp_Tdη}/\langle\frac{dN_{ch}}{dη}\rangle)^{pp,INEL}}$ as a function of $\langle dN_{ch}/dη\rangle$. The values of $R_{AA}$ and $R_{AA}^N$ at $\langle dN_{ch}/dη\rangle$ and $\langle N_{part} \rangle$ experimentally measured and estimated by Glauber MC, respectively, for O-O collisions are in good agreement with the systematics obtained for A-A collisions.

Figures (4)

• Figure 1: $\langle dN_{bin} \rangle$/[$\langle dN_{ch}/d\eta \rangle^{A-A}/\langle dN_{ch}/d\eta \rangle^{pp}$] values in O-O collision at $\sqrt{s_{NN}}$=5.36 TeV are presented by yellow squares using recently measured $\langle dN_{ch}/d\eta \rangle$ for different centralities by the ALICE StraMar Collaboration on top of Fig.14 from Pet_1
• Figure 2: $R_{AA}$ as a function of $\langle N_{part} \rangle$ from Pet_2 over which the corresponding experimental value for O-O is represented by the yellow box.
• Figure 3: $R_{AA}$ as a function of $\langle dN_{ch}/d\eta \rangle$ from Pet_2 on which the corresponding experimental value for O-O is represented by the yellow box.
• Figure 4: $R_{AA}^N$ as a function of $\langle dN_{ch}/d\eta \rangle$ from Pet_2 over which the corresponding experimental value for O-O is represented by the yellow box.