Identified charged-hadron production in p + Al, 3He +Au, and Cu + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and in U + U collisions at $\sqrt{s_{NN}}$ = 193 GeV

• Published in: Physical review. C 2024-05, Vol.109 (5)
• Main Authors: Abdulameer, N. J., Ajitanand, N. N., Alexander, J., Alfred, M., Aoki, K., Berdnikov, A., Black, D., Blau, D. S., Bumazhnov, V., Campbell, S., Cervantes, R., Choi, I. J., Choi, J. B., Choi, S., Chujo, T., Connors, M., Cronin, N., Drees, A., Engelmore, T., Feege, N., Firak, D., Fitzgerald, D., Frawley, A. D., Gal, C., Giles, M., Haggerty, J. S., Hayano, R., Hemmick, T. K., Hodges, A., Huang, J., Jiang, X., Jouan, D., Kanda, S., Kapukchyan, D., Kawall, D., Key, J. A., Kimelman, B., Kim, C., Kim, G. W., Kim, M., Kincses, D., Kleinjan, D., Kofarago, M., Komkov, B., Krizek, F., Lee, G. H., Lee, J., Majoros, T., Manko, V. I., McGlinchey, D., McKinney, C., Meles, A., Meredith, B., Mibe, T., Mignerey, A. C., Milov, A., Mishra, D. K., Mitrankov, Iu, Mohanty, A. K., Morrison, D. P., Mulilo, B., Nagashima, T., Nagle, J. L., Nagy, M. I., Nakamiya, Y., Nelson, S., Nouicer, R., Oide, H., Okada, K., Ozawa, K., Park, J. S., Park, S., Park, S. K., Patel, L., Perry, J., Petti, R., Pinson, R., Pisani, R. P., Qu, H., Rinn, T., Riveli, N., Roach, D., Rosati, M., Seto, R., Sharma, D., Shaver, A., Shioya, T., Shoji, K., Silva, C. L., Slunečka, M., Sourikova, I. V., Stankus, P. W., Timilsina, A., Tomášek, M., Torii, H., Whitaker, S., Xia, B., Xu, Q., Yalcin, S., Younus, I.
• Format: Article
• Language: English
• Subjects: hadron production; hadrons; kaons; NUCLEAR PHYSICS AND RADIATION PHYSICS; pions; protons; relativistic heavy-ion collisions
• ISSN: 2469-9985; 2469-9993

The PHENIX experiment has performed a systematic study of identified charged-hadron ($π^±$, $K^±$, $p$, $\overline{p}$) production at midrapidity in $p$ + Al, 3He +Au, and Cu + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV and U + U collisions at $\sqrt{s_{NN}}$ = 193 GeV. Identified charged-hadron invariant transverse-momentum ($p_T$) and transverse-mass ($m_T$) spectra are presented and interpreted in terms of radially expanding thermalized systems. The particle ratios of $K/π$ and $p/π$ have been measured in different centrality ranges of large (Cu + Au and U + U) and small ($p$ + Al and 3He +Au) collision systems. The values of $K/π$ ratios measured in all considered collision systems were found to be consistent with those measured in $p + p$ collisions. However, the values of $p/π$ ratios measured in large collision systems reach the values of ≈0.6, which is a factor of ≈2 larger than in $p + p$ collisions. These results can be qualitatively understood in terms of the baryon enhancement expected from hadronization by recombination. Identified charged-hadron nuclear-modification factors ($R_{AB}$) are also presented. Enhancement of proton $R_{AB}$ values over meson $R_{AB}$ values was observed in central 3He +Au, Cu + Au, and U + U collisions. Here, the proton $R_{AB}$ values measured in the $p$ + Al collision system were found to be consistent with $R_{AB}$ values of $Φ$, $π^±$, $K^±$, and $π^0$ mesons, which may indicate that the size of the system produced in $p$ + Al collisions is too small for recombination to cause a noticeable increase in proton production.