Disentangling centrality bias and final-state effects in the production of high-$p_T$ $π^0$ using direct $γ$ in $d$$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV

Autor: Abdulameer, N. J., Acharya, U., Aidala, C., Akiba, Y., Alfred, M., Aoki, K., Apadula, N., Ayuso, C., Babintsev, V., Barish, K. N., Bathe, S., Bazilevsky, A., Belmont, R., Berdnikov, A., Berdnikov, Y., Bichon, L., Blankenship, B., Blau, D. S., Boer, M., Bok, J. S., Borisov, V., Brooks, M. L., Bryslawskyj, J., Bumazhnov, V., Butler, C., Campbell, S., Roman, V. Canoa, Chiu, M., Connors, M., Corliss, R., Morales, Y. Corrales, Csanád, M., Csörgő, T., Liu, L. D., Danley, T. W., Daugherity, M. S., David, G., Dean, C. T., DeBlasio, K., Dehmelt, K., Denisov, A., Deshpande, A., Desmond, E. J., Doomra, V., Do, J. H., Drees, A., Drees, K. A., Dumancic, M., Durham, J. M., Durum, A., Elder, T., Enokizono, A., Esha, R., Fadem, B., Fan, W., Feege, N., Finger, M., Firak, D., Fitzgerald, D., Fokin, S. L., Frantz, J. E., Franz, A., Frawley, A. D., Fukuda, Y., Gal, C., Garg, P., Ge, H., Giles, M., Goto, Y., Grau, N., Greene, S. V., Gunji, T., Hachiya, T., Haggerty, J. S., Hahn, K. I., Han, S. Y., Harvey, M., Hasegawa, S., Haseler, T. O. S., Hemmick, T. K., He, X., Hill, K., Hodges, A., Homma, K., Hong, B., Hoshino, T., Hotvedt, N., Huang, J., Imrek, J., Inaba, M., Isenhower, D., Ito, Y., Ivanishchev, D., Jacak, B. V., Ji, Z., Johnson, B. M., Jorjadze, V., Jouan, D., Jumper, D. S., Kang, J. H., Kapukchyan, D., Karthas, S., Kazantsev, A. V., Khachatryan, V., Khanzadeev, A., Khatiwada, A., Kim, C., Kim, D. J., Kim, E. -J., Kim, M., Kim, M. H., Kim, T., Kincses, D., Kingan, A., Kistenev, E., Koblesky, T., Kotov, D., Kovacs, L., Kudo, S., Kurgyis, B., Kurita, K., Lajoie, J. G., Lallow, E. O., Larionova, D., Lebedev, A., Lee, S. H., Leitch, M. J., Leung, Y. H., Lewis, N. A., Lim, S. H., Liu, M. X., Li, X., Loggins, V. -R., Loomis, D. A., Lynch, D., Lökös, S., Majoros, T., Makek, M., Malaev, M., Manko, V. I., Mannel, E., Masuda, H., McCumber, M., McGlinchey, D., Mignerey, A. C., Mihalik, D. E., Milov, A., Mishra, D. K., Mitchell, J. T., Mitrankova, M., Mitrankov, Iu., Mitsuka, G., Mondal, M. M., Moon, T., Morrison, D. P., Morrow, S. I., Muhammad, A., Mulilo, B., Murakami, T., Murata, J., Nagai, K., Nagashima, K., Nagashima, T., Nagle, J. L., Nagy, M. I., Nakagawa, I., Nakagomi, H., Nakano, K., Nattrass, C., Nelson, S., Nouicer, R., Novitzky, N., Novotny, R., Novák, T., Nukazuka, G., Nyanin, A. S., O'Brien, E., Ogilvie, C. A., Oh, J., Koop, J. D. Orjuela, Orosz, M., Osborn, J. D., Oskarsson, A., Ozawa, K., Pantuev, V., Papavassiliou, V., Park, J. S., Park, S., Patel, M., Pate, S. F., Peng, W., Perepelitsa, D. V., Perera, G. D. N., PerezLara, C. E., Petti, R., Phipps, M., Pinkenburg, C., Potekhin, M., Pun, A., Purschke, M. L., Radzevich, P. V., Ramasubramanian, N., Read, K. F., Riabov, V., Riabov, Y., Richford, D., Rinn, T., Rosati, M., Rowan, Z., Runchey, J., Sakaguchi, T., Sako, H., Samsonov, V., Sarsour, M., Sato, K., Sato, S., Schaefer, B., Schmoll, B. K., Seidl, R., Sen, A., Seto, R., Sexton, A., Sharma, D., Shein, I., Shibata, M., Shibata, T. -A., Shigaki, K., Shimomura, M., Shi, Z., Silva, C. L., Silvermyr, D., Slunečka, M., Smith, K. L., Sorensen, S. P., Sourikova, I. V., Stankus, P. W., Stoll, S. P., Sugitate, T., Sukhanov, A., Sun, Z., Syed, S., Takahama, R., Takeda, A., Tanida, K., Tannenbaum, M. J., Tarafdar, S., Taranenko, A., Tarnai, G., Tieulent, R., Timilsina, A., Todoroki, T., Tomášek, M., Towell, C. L., Towell, R. S., Tserruya, I., Ueda, Y., Ujvari, B., van Hecke, H. W., Vazquez-Carson, S., Velkovska, J., Virius, M., Vrba, V., Wang, X. R., Wang, Z., Watanabe, Y., Wong, C. P., Xu, C., Xu, Q., Yamaguchi, Y. L., Yanovich, A., Yin, P., Yoon, I., Yoo, J. H., Yushmanov, I. E., Yu, H., Zajc, W. A., Zou, L.
Rok vydání: 2023
Předmět:
DOI: 10.48550/arxiv.2303.12899
Popis: PHENIX presents a simultaneous measurement of the production of direct $γ$ and $π^0$ in $d$$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV over a $p_T$ range of 7.5 to 18 GeV/$c$ for different event samples selected by event activity, i.e. charged-particle multiplicity detected at forward rapidity. Direct-photon yields are used to empirically estimate the contribution of hard-scattering processes in the different event samples. Using this estimate, the average nuclear-modification factor $R_{d\rm Au,EXP}^{γ^{\rm dir}}$ is $0.925{\pm}0.023({\rm stat}){\pm}0.15^{\rm (scale)}$, consistent with unity for minimum-bias (MB) $d$$+$Au events. For event classes with moderate event activity, $R_{d\rm Au,EXP}^{γ^{\rm dir}}$ is consistent with the MB value within 5\% uncertainty. These results confirm that the previously observed enhancement of high-$p_T$ $π^0$ production found in small-system collisions with low event activity is a result of a bias in interpreting event activity within the Glauber framework. In contrast, for the top 5\% of events with the highest event activity, $R_{d\rm Au,EXP}^{γ^{\rm dir}}$ is suppressed by 20\% relative to the MB value with a significance of $4.5σ$, which may be due to final-state effects.
279 authors from 69 institutions, 8 pages, 3 figures, v1 is version submitted to Physical Review Letters. HEPdata tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.html
Databáze: OpenAIRE