Quark Matter 2025

sPHENIX measurement of neutral meson transverse single spin asymmetry in high-statistics polarized p+p collisions

Not scheduled

20m

Goethe University Frankfurt, Campus Westend, Theodor-W.-Adorno-Platz 1, 60629 Frankfurt am Main, Germany

Poster Initial state of hadronic and electron-ion collisions & nuclear structure Poster session 1

Speaker

Dylan Neff (Université Paris-Saclay (FR))

Description

The sPHENIX experiment is a next-generation collider detector at RHIC designed for rare jet and heavy flavor probes of polarized p+p collisions. The experiment includes a large-acceptance, granular electromagnetic calorimeter (EMCal) and very high-rate data acquisition plus trigger system. In RHIC Run-24, sPHENIX sampled 107/pb of transversely polarized p+p collision data at 200 GeV using an efficient high-p$_T$ photon trigger. This dataset represents a nearly-tenfold increase of the luminosity times acceptance compared to previous EMCal-based datasets for this collision energy. This talk presents measurements of the transverse single spin asymmetry for neutral pions and $\eta$ mesons in the two-photon decay channel over a significantly extended kinematic range compared to previous measurements at RHIC. For the $\eta$ meson, the decay photons remain well-separated in the granular EMCal out to very high p$_T$.