Nonprompt direct-photon production in Au+Au collisions at sNN=200 GeV

著者: N. J. Abdulameer, U. Rajendra Acharya, A. Adare, C. Aidala, N. N. Ajitanand, Y. Akiba, M. Alfred, N. Apadula, H. Asano, B. Azmoun, V. Babintsev, M. Bai, N. S. Bandara, B. Bannier, K. N. Barish, S. Bathe, A. Bazilevsky, M. Beaumier, S. Beckman, R. Belmont, A. Berdnikov, Y. Berdnikov, L. Bichon, B. Blankenship, D. Blau, J. S. Bok, V. Borisov, K. Boyle, M. L. Brooks, J. Bryslawskyj, V. Bumazhnov, S. Campbell, V. Canoa Roman, C.-H. Chen, M. Chiu, C. Y., I. J. Choi, J. B. Choi, T. Chujo, Z. Citron, M. Connors, R. Corliss, Y. Corrales Morales, M. Csanád, T. Csörgő, T. W. Danley, A. Datta, M. S. Daugherity, G. David, C. T. Dean, K. DeBlasio, K. Dehmelt, A. Denisov, A. Deshpande, E. J. Desmond, A. Dion, P. B. Diss, J. H., V. Doomra, A. Drees, K. A. Drees, J. M. Durham, A. Durum, A. Enokizono, R. Esha, B. Fadem, W. Fan, N. Feege, D. E. Fields, M. Finger, M. Finger, D. Firak, D. S. Fitzgerald, S. Fokin, J. E. Frantz, A. Franz, A. D. Frawley, P. Gallus, C. Gal, P. Garg, Hui Ming Ge, M. Giles, F. Giordano, A. Glenn, Y. Goto, N. Grau, S. V. Greene, M. Große Perdekamp, T. Gunji, Tingting Guo, T. Hachiya, J. S. Haggerty, K. I. Hahn, H. Hamagaki, H. F. Hamilton, J. Hanks, Seyoung Han, M. Harvey, Shuji Hasegawa, T. O. S. Haseler, K. Hashimoto, T. K. Hemmick, X. He, J. C. Hill, A. Hodges, R. S. Hollis, K. Homma, B. Hong, T. Hoshino, N. Hotvedt, J. Huang, K. Imai, M. Inaba, A. Iordanova, D. Isenhower, D. Ivanishchev, B. V. Jacak, M. Jezghani, X. Jiang, Z. Ji, B. M. Johnson, D. Jouan, D. S. Jumper, S. Kanda, J. H. Kang, D. Kawall, A. V. Kazantsev, J. A. Key, V. Khachatryan, A. Khanzadeev, A. Khatiwada, B. Kimelman, Chong Kim, D. J. Kim, E. J. Kim, G. W. Kim, M. Kim, T. Kim, D. Kincses, A. Kingan, E. Kistenev, R. Kitamura, J. Klatsky, D. Kleinjan, P. Kline, T. Koblesky, B. Komkov, D. Kotov, L. Kovacs, B. Kurgyis, K. Kurita, M. Kurosawa, Y. Kwon, J. G. Lajoie, D. Larionova, A. Lebedev, S. Lee, S. H. Lee, M. J. Leitch, N. A. Lewis, S. H. Lim, X. Li, X. Li, X. Li, D. A. Loomis, D. Lynch, S. Lökòs, T. Majoros, Y. I. Makdisi, M. Makek, A. Manion, V. I. Manko, E. Mannel, M. McCumber, P. L. McGaughey, D. McGlinchey, C. McKinney, A. Meles, M. Mendoza, A. C. Mignerey, A. Milov, D. K. Mishra, J. T. Mitchell, M. Mitrankova, Iu. Mitrankov, S. Miyasaka, S. Mizuno, Ali Mohamed, A. K. Mohanty, M. M. Mondal, P. Montuenga, T. Moon, D. P. Morrison, T. V. Moukhanova, B. Mulilo, T. Murakami, J. Murata, A. Mwai, K. Nagashima, J. L. Nagle, M. I. Nagy, I. Nakagawa, H. Nakagomi, K. Nakano, C. Nattrass, S. Nelson, P. K. Netrakanti, T. Niida, S. Nishimura, R. Nouicer, N. Novitzky, T. Novák, G. Nukazuka, A. S. Nyanin, E. O'Brien, C. A. Ogilvie, J. D. Orjuela Koop, M. Orosz, J. D. Osborn, A. Oskarsson, K. Ozawa, R. Pak, V. Pantuev, V. Papavassiliou, J. S. Park, S. Park, M. Patel, S. F. Pate, J.-C. Peng, W. Peng, D. V. Perepelitsa, G. D. N. Perera, D. Yu. Peressounko, C. E. Pérez Lara, John Oliver Perry, R. Petti, C. Pinkenburg, R. Pinson, R. P. Pisani, M. Potekhin, A. Pun, M. L. Purschke, P. V. Radzevich, J. Rak, N. Ramasubramanian, B. J. Ramson, I. Ravinovich, K. F. Read, David M. Reynolds, V. Riabov, Y. Riabov, D. Richford, T. Rinn, S. D. Rolnick, M. Rosati, Z. Rowan, J. G. Rubin, J. Runchey, B. Sahlmueller, N. Saito, T. Sakaguchi, H. Sako, V. Samsonov, M. Sarsour, S. Sato, B. D. Schaefer, B. K. Schmoll, K. Sedgwick, R. Seidl, A. Sen, R. Seto, P. Sett, A. Sexton, D. Sharma, I. Shein, Z. Shi, M. Shibata, T.-A. Shibata, K. Shigaki, M. Shimomura, P. Shukla, A. Sickles, C. L. Silva, D. Silvermyr, B. K. Singh, C. P. Singh, V. Singh, M. Slunečka, K. Smith, M. Snowball, R. A. Soltz, W. E. Sondheim, S. P. Sorensen, I. V. Sourikova, P. W. Stankus, M. Stepanov, S. P. Stoll, T. Sugitate, A. Sukhanov, T. Sumita, J. Sun, Z. Sun, J. Sziklai, R. Takahama, A. Taketani, K. Tanida, M. J. Tannenbaum, S. Tarafdar, A. Taranenko, R. Tieulent, A. Timilsina, T. Todoroki, M. Tomášek, C. L. Towell, R. S. Towell, R. S. Towell, I. Tserruya, Y. Ueda, B. Ujvari, H. W. van Hecke, J. Velkovska, M. Virius, V. Vrba, X. R. Wang, Z. Wang, Y. Watanabe, Yasushi Watanabe, F. Wei, A. S. White, C. P. Wong, C. L. Woody, M. Wysocki, B. Xia, L. Xue, Ş. Yalçın, Y. L. Yamaguchi, A. Yanovich, Z. Yin, I. Yoon, J. H. Yoo, I. E. Yushmanov, H. Yu, W. A. Zajc, A. Zelenski, S. Zhou, L. Zou - Physical review. C 2024 被引用: 16

The measurement of the direct-photon spectrum from $\mathrm{Au}+\mathrm{Au}$ collisions at $\sqrt{{s}_{{}_{NN}}}=200$ GeV is presented by the PHENIX Collaboration using the external-photon-conversion technique for 0%--93% central collisions in a transverse-momentum (${p}_{T}$) range of 0.8--10 $\text{GeV}/c$. An excess of direct photons, above prompt-photon production from hard-scattering processes, is observed for ${p}_{T}<6\phantom{\rule{4pt}{0ex}}\text{GeV}/c$. Nonprompt direct photons are measured by subtracting the prompt component, which is estimated as ${N}_{\mathrm{coll}}$-scaled direct photons from $p+p$ collisions at 200 GeV, from the direct-photon spectrum. Results are obtained for $0.8<{p}_{T}<6.0\phantom{\rule{4pt}{0ex}}\text{GeV}/c$ and suggest that the spectrum has an increasing inverse slope from $\ensuremath{\approx}0.2$ to 0.4 $\text{GeV}/c$ with increasing ${p}_{T}$, which indicates a possible sensitivity of the measurement to photons from earlier stages of the evolution of the collision. In addition, like the direct-photon production, the ${p}_{T}$-integrated nonprompt direct-photon yields also follow a power-law scaling behavior as a function of collision-system size. The exponent, $\ensuremath{\alpha}$, for the nonprompt component is found to be consistent with 1.1 with no apparent ${p}_{T}$ dependence.