Parker Solar Probe Observations of Proton Beams Simultaneous with Ion-scale Waves - Verniero, JL; Larson, DE; Livi, R; Rahmati, A; McManus, MD; Pyakurel, PS; Klein, KG; Bowen, TA; Bonnell, JW; Alterman, BL; Whittlesey, PL; Malaspina, DM; et al. (ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2020)