Nuclear Modification of $\pi^0$ Production in OO Collisions with ALICE

TL;DR

This paper reports the first measurement of the nuclear modification factor for neutral pions in oxygen-oxygen collisions at LHC, revealing significant suppression indicative of hot medium effects.

Contribution

First measurement of $c0^0$ nuclear modification factor in OO collisions at LHC, providing new insights into parton energy loss in hot nuclear matter.

Findings

Significant suppression of $c0^0$ production observed in OO collisions.

Results deviate from models considering only cold nuclear matter effects.

Measurement offers new data for understanding hot medium effects in small systems.

Abstract

We present the first results on the $\pi^0$ nuclear modification factor $R_{OO}$ in OO collisions at LHC energies by the ALICE experiment. The measurement of the modification of hadron production in nuclear collisions compared to a vacuum baseline in pp collisions is a valuable probe for parton energy loss in the hot medium. The ALICE $R_{OO}$ results show significant (up to 4$\sigma$) suppression of $\pi^0$ production in OO collisions compared to the pp reference, and up to 2.4$\sigma$ deviation w.r.t. model predictions that include only cold nuclear matter effects.