Nuclear-Modification Factor for Open-Heavy-Flavor Production at Forward Rapidity in Cu+Cu Collisions at sqrt(s_NN)=200 GeV

/ Authors

A. Adare, S. Afanasiev, C. Aidala, N. Ajitanand, Y. Akiba, H. Al-Bataineh, J. Alexander, K. Aoki, L. Aphecetche, R. Armendariz

and 366 more authors

S. Aronson, J. Asai, E. Atomssa, R. Averbeck, T. Awes, B. Azmoun, V. Babintsev, G. Baksay, L. Baksay, A. Baldisseri, K. Barish, P. Barnes, B. Bassalleck, S. Bathe, S. Batsouli, V. Baublis, A. Bazilevsky, S. Belikov, R. Bennett, Y. Berdnikov, A. Bickley, J. Boissevain, H. Borel, K. Boyle, M. Brooks, H. Buesching, V. Bumazhnov, G. Bunce, S. Butsyk, S. Campbell, B. S. Chang, J. Charvet, S. Chernichenko, C. Chi, J. Chiba, M. Chiu, I. Choi, T. Chujo, P. Chung, A. Churyn, V. Cianciolo, C. Cleven, B. Cole, M. Comets, P. Constantin, M. Csan'ad, T. CsorgHo, T. Dahms, K. Das, G. David, M. Deaton, K. Dehmelt, H. Delagrange, A. Denisov, D. d’Enterria, A. Deshpande, E. Desmond, O. Dietzsch, A. Dion, M. Donadelli, O. Drapier, A. Drees, A. Dubey, A. Durum, V. Dzhordzhadze, Y. Efremenko, J. Egdemir, F. Ellinghaus, W. Emam, A. Enokizono, H. En’yo, S. Esumi, K. O. Eyser, D. Fields, M. Finger, Jr., F. Fleuret, S. Fokin, Z. Fraenkel, J. Frantz, A. Franz, A. Frawley, K. Fujiwara, Y. Fukao, T. Fusayasu, S. Gadrat, I. Garishvili, A. Glenn, H. Gong, M. Gonin, J. Gosset, Y. Goto, R. G. Cassagnac, N. Grau, S. Greene, M. Perdekamp, T. Gunji, H. Gustafsson, T. Hachiya, A. Henni, C. Haegemann, J. Haggerty, H. Hamagaki, R. Han, H. Harada, E. Hartouni, K. Haruna, E. Haslum, R. Hayano, X. He, M. Heffner, T. Hemmick, T. Hester, H. Hiejima, J. Hill, R. Hobbs, M. Hohlmann, W. Holzmann, K. Homma, B. Hong, T. Horaguchi, D. Hornback, T. Ichihara, H. Iinuma, K. Imai, M. Inaba, Y. Inoue, D. Isenhower, L. Isenhower, M. Ishihara, T. Isobe, M. Issah, A. Isupov, B. Jacak, J. Jia, J. Jin, O. Jinnouchi, B. Johnson, K. Joo, D. Jouan, F. Kajihara, S. Kametani, N. Kamihara, J. Kamin, M. Kaneta, J. Kang, H. Kanou, D. Kawall, A. Kazantsev, A. Khanzadeev, J. Kikuchi, D. H. Kim, D. Kim, E. Kim, E. Kinney, '. Kiss, E. Kistenev, A. Kiyomichi, J. Klay, C. Klein-boesing, L. Kochenda, V. Kochetkov, B. Komkov, M. Konno, D. Kotchetkov, A. Kozlov, A. Kr'al, A. Kravitz, J. Kubart, G. Kunde, N. Kurihara, K. Kurita, M. Kweon, Y. Kwon, G. Kyle, R. Lacey, Y. Lai, J. Lajoie, A. Lebedev, D. Lee, M. K. Lee, T. Lee, M. Leitch, M. Leite, B. Lenzi, X. Li, T. Livska, A. Litvinenko, M. Liu, B. Love, D. Lynch, C. Maguire, Y. Makdisi, A. Malakhov, M. Malik, V. Manko, Y. Mao, L. Mavsek, H. Masui, F. Matathias, M. McCumber, P. McGaughey, Y. Miake, P. Mikevs, K. Miki, T. E. Miller, A. Milov, S. Mioduszewski, M. Mishra, J. Mitchell, M. Mitrovski, A. Morreale, D. Morrison, T. Moukhanova, D. Mukhopadhyay, J. Murata, S. Nagamiya, Y. Nagata, J. Nagle, M. Naglis, I. Nakagawa, Y. Nakamiya, T. Nakamura, K. Nakano, J. Newby, M. Nguyen, B. Norman, R. Nouicer, A. Nyanin, E. O'brien, S. Oda, C. Ogilvie, H. Ohnishi, M. Oka, K. Okada, O. Omiwade, A. Oskarsson, M. Ouchida, K. Ozawa, R. Pak, D. Pal, A. Palounek, V. Pantuev, V. Papavassiliou, J. Park, W. Park, S. Pate, H. Pei, J. Peng, H. Pereira, V. Peresedov, D. Peressounko, C. Pinkenburg, M. Purschke, A. Purwar, H. Qu, J. Rak, A. Rakotozafindrabe, I. Ravinovich, K. Read, S. Rembeczki, M. Reuter, K. Reygers, V. Riabov, Y. Riabov, G. Roche, A. Romañá, M. Rosati, S. Rosendahl, P. Rosnet, P. Rukoyatkin, V. Rykov, B. Sahlmueller, N. Saito, T. Sakaguchi, S. Sakai, H. Sakata, V. Samsonov, S. Sato, S. Sawada, J. Seele, R. Seidl, V. Semenov, R. Seto, D. Sharma, I. Shein, A. Shevel, T. Shibata, K. Shigaki, M. Shimomura, K. Shoji, A. Sickles, C. Silva, D. Silvermyr, C. Silvestre, K. Sim, C. P. Singh, V. Singh, S. Skutnik, M. Slunevcka, A. Soldatov, R. Soltz, W. Sondheim, S. Sorensen, I. Sourikova, F. Staley, P. Stankus, E. Stenlund, M. Stepanov, A. Ster, S. Stoll, T. Sugitate, C. Suire, J. Sziklai, T. Tabaru, S. Takagi, E. M. Takagui, A. Taketani, Y. Tanaka, K. Tanida, M. Tannenbaum, A. Taranenko, P. Tarj'an, T. Thomas, M. Togawa, A. Toia, J. Tojo, L. Tom'avsek, H. Torii, R. Towell, V. Tram, I. Tserruya, Y. Tsuchimoto, C. Vale, H. Valle, H. W. Hecke, J. Velkovska, R. V'ertesi, A. Vinogradov, M. Virius, V. Vrba, E. Vznuzdaev, M. Wagner, D. Walker, X. Wang, Y. Watanabe, J. Wessels, S. White, D. Winter, C. Woody, M. Wysocki, W. Xie, Y. Yamaguchi, A. Yanovich, Z. Yasin, J. Ying, S. Yokkaichi, G. Young, I. Younus, I. Yushmanov, W. Zajc, O. Zaudtke, C. Zhang, S. Zhou, J. Zim'anyi, L. Zolin

/ Abstract

Background: Heavy-flavor production in p + p collisions is a good test of perturbative-quantum-chromodynamics (pQCD) calculations. Modification of heavy-flavor production in heavy-ion collisions relative to binary-collision scaling from p + p results, quantified with the nuclear-modification factor (R-AA), provides information on both cold-and hot-nuclear-matter effects. Midrapidity heavy-flavor R-AA measurements at the Relativistic Heavy Ion Collider have challenged parton-energy-loss models and resulted in upper limits on the viscosity-entropy ratio that are near the quantum lower bound. Such measurements have not been made in the forward-rapidity region. Purpose: Determine transverse-momentum (p(T)) spectra and the corresponding R-AA for muons from heavy-flavor meson decay in p + p and Cu + Cu collisions at root s(NN) = 200 GeV and y = 1.65. Method: Results are obtained using the semileptonic decay of heavy-flavor mesons into negative muons. The PHENIX muon-arm spectrometers measure the p(T) spectra of inclusive muon candidates. Backgrounds, primarily due to light hadrons, are determined with a Monte Carlo calculation using a set of input hadron distributions tuned to match measured-hadron distributions in the same detector and statistically subtracted. Results: The charm-production cross section in p + p collisions at root s = 200 GeV, integrated over p(T) and in the rapidity range 1.4 < y < 1.9, is found to be d(sigma e (e) over bar)/dy = 0.139 +/- 0.029 (stat)(-0.058)(+0.051) (syst) mb. This result is consistent with a perturbative fixed-order-plus-next-to-leading-log calculation within scale uncertainties and is also consistent with expectations based on the corresponding midrapidity charm-production cross section measured by PHENIX. The R-AA for heavy-flavor muons in Cu + Cu collisions is measured in three centrality bins for 1 < p(T) < 4 GeV/c. Suppression relative to binary-collision scaling (R-AA < 1) increases with centrality. Conclusions: Within experimental and theoretical uncertainties, the measured charm yield in p + p collisions is consistent with state-of-the-art pQCD calculations. Suppression in central Cu + Cu collisions suggests the presence of significant cold-nuclear-matter effects and final-state energy loss.

Journal: Physical Review C

DOI: 10.1103/PhysRevC.86.024909