Princeton University Dark Cosmos Seminar

Abstract: The PADME experiment is a fixed-target high-energy physics setup located in Frascati, Italy, originally designed to search for dark photon production via collisions between a positron beam and a thin diamond target. In 2022, the experiment was adapted for a timely search for the X17 particle, a hypothetical boson with a mass around 17 MeV, motivated by anomalies observed in nuclear transitions of beryllium, helium, and carbon atoms. We present the results from this first dedicated search for the X17, revealing a mild excess of events near the expected 17 MeV center-of-mass energy. The talk will cover the experimental setup, the theoretical motivation for X17, details of the collected dataset, and plans for future data taking aimed at confirming or refuting the X17 hypothesis.