Measurement of transverse single-spin asymmetries in π0 and η Meson production in √s = 200 GEV p↑ + p collisions with sPHENIX

The sPHENIX experiment is a next-generation collider detector at the Relativistic Heavy Ion Collider (RHIC) designed for rare jet and heavy-flavor probes of Au + Au, p + Au, and polarized p + p collisions. The experiment includes a large acceptance, granular electromagnetic calorimeter and very high-rate data acquisition plus trigger system. In RHIC Run-24, sPHENIX sampled 107 pb−1 of collision data with transversely polarized protons at √s = 200 GeV using an efficient high-pT photon trigger. This dissertation describes the extraction of transverse single-spin asymmetries in inclusive production of π0 and η mesons decaying into two photons. Such observables are sensitive to multi-parton correlations in the proton, which are related to transverse-momentum dependent (TMD) effects. The new sPHENIX data set allows for significant extension of the kinematic range covered by previous RHIC mid-rapidity measurements. The results are corrected for background contributions and three different sources of systematic uncertainties are considered: the calculation method, the method of background subtraction, and contributions from possible false asymmetries due to instrumental effects. The results are presented and compared to existing measurements from the PHENIX experiment.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Physics

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Mattson, Gregory

Contributors dc:contributor

• Riedl, Caroline
• Sickles, Anne
• Grosse Perdekamp, Matthias
• Noronha, Jorge
• Eckstein, James

• nucleon structure
• TSSA
• transverse single-spin asymmetry
• sPHENIX

Statement dc:rights

• Copyright 2025 Gregory Mattson

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132456

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132456