Azimuthal anisotropy of π⁰ production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry

A Adare; S Afanasiev; C Aidala; N N Ajitanand; Y Akiba; H Al-Bataineh; J Alexander; K Aoki; Y Aramaki; E T Atomssa; R Averbeck; T C Awes; B Azmoun; V Babintsev; M Bai; G Baksay; L Baksay; K N Barish; B Bassalleck; A T Basye; S Bathe; V Baublis; C Baumann; A Bazilevsky; S Belikov; R Belmont; R Bennett; A Berdnikov; Y Berdnikov; A A Bickley; J S Bok; K Boyle; M L Brooks; H Buesching; V Bumazhnov; G Bunce; S Butsyk; C M Camacho; S Campbell; C-H Chen; C Y Chi; M Chiu; I J Choi; R K Choudhury; P Christiansen; T Chujo; P Chung; O Chvala; V Cianciolo; Z Citron; B A Cole; M Connors; P Constantin; M Csanád; T Csörgo; T Dahms; S Dairaku; I Danchev; K Das; A Datta; G David; A Denisov; A Deshpande; E J Desmond; O Dietzsch; A Dion; M Donadelli; O Drapier; A Drees; K A Drees; J M Durham; A Durum; D Dutta; S Edwards; Y V Efremenko; F Ellinghaus; T Engelmore; A Enokizono; H En'yo; S Esumi; B Fadem; D E Fields; M Finger Jr; M Finger; F Fleuret; S L Fokin; Z Fraenkel; J E Frantz; A Franz; A D Frawley; K Fujiwara; Y Fukao; T Fusayasu; I Garishvili; A Glenn; H Gong; M Gonin; Y Goto; R Granier de Cassagnac; N Grau; S V Greene; M Grosse Perdekamp; T Gunji; H-Å Gustafsson; J S Haggerty; K I Hahn; H Hamagaki; J Hamblen; J Hanks; R Han; E P Hartouni; E Haslum; R Hayano; M Heffner; S Hegyi; T K Hemmick; T Hester; X He; J C Hill; M Hohlmann; W Holzmann; K Homma; B Hong; T Horaguchi; D Hornback; S Huang; T Ichihara; R Ichimiya; J Ide; Y Ikeda; K Imai; M Inaba; D Isenhower; M Ishihara; T Isobe; M Issah; A Isupov; D Ivanischev; B V Jacak; J Jia; J Jin; B M Johnson; K S Joo; D Jouan; D S Jumper; F Kajihara; S Kametani; N Kamihara; J Kamin; J H Kang; J Kapustinsky; K Karatsu; D Kawall; M Kawashima; A V Kazantsev; T Kempel; A Khanzadeev; K M Kijima; B I Kim; D H Kim; D J Kim; E J Kim; E Kim; S H Kim; Y J Kim; E Kinney; K Kiriluk; A Kiss; E Kistenev; L Kochenda; B Komkov; M Konno; J Koster; D Kotchetkov; A Kozlov; A Král; A Kravitz; G J Kunde; K Kurita; M Kurosawa; Y Kwon; G S Kyle; R Lacey; Y S Lai; J G Lajoie; A Lebedev; D M Lee; J Lee; K B Lee; K Lee; K S Lee; M J Leitch; M A L Leite; E Leitner; B Lenzi; P Liebing; L A Linden Levy; T Liška; A Litvinenko; H Liu; M X Liu; X Li; B Love; R Luechtenborg; D Lynch; C F Maguire; Y I Makdisi; A Malakhov; M D Malik; V I Manko; E Mannel; Y Mao; H Masui; F Matathias; M McCumber; P L McGaughey; N Means; B Meredith; Y Miake; A C Mignerey; P Mikeš; K Miki; A Milov; M Mishra; J T Mitchell; A K Mohanty; Y Morino; A Morreale; D P Morrison; T V Moukhanova; J Murata; S Nagamiya; J L Nagle; M Naglis; M I Nagy; I Nakagawa; Y Nakamiya; T Nakamura; K Nakano; J Newby; M Nguyen; R Nouicer; A S Nyanin; E O'Brien; S X Oda; C A Ogilvie; K Okada; M Oka; Y Onuki; A Oskarsson; M Ouchida; K Ozawa; R Pak; V Pantuev; V Papavassiliou; I H Park; J Park; S K Park; W J Park; S F Pate; H Pei; J-C Peng; H Pereira; V Peresedov; D Yu Peressounko; C Pinkenburg; R P Pisani; M Proissl; M L Purschke; A K Purwar; H Qu; J Rak; A Rakotozafindrabe; I Ravinovich; K F Read; K Reygers; V Riabov; Y Riabov; E Richardson; D Roach; G Roche; S D Rolnick; M Rosati; C A Rosen; S S E Rosendahl; P Rosnet; P Rukoyatkin; P Ružička; B Sahlmueller; N Saito; T Sakaguchi; K Sakashita; V Samsonov; S Sano; T Sato; S Sawada; K Sedgwick; J Seele; R Seidl; A Yu Semenov; R Seto; D Sharma; I Shein; T-A Shibata; K Shigaki; M Shimomura; K Shoji; P Shukla; A Sickles; C L Silva; D Silvermyr; C Silvestre; K S Sim; B K Singh; C P Singh; V Singh; M Slunečka; R A Soltz; W E Sondheim; S P Sorensen; I V Sourikova; N A Sparks; P W Stankus; E Stenlund; S P Stoll; T Sugitate; A Sukhanov; J Sziklai; E M Takagui; A Taketani; R Tanabe; Y Tanaka; K Tanida; M J Tannenbaum; S Tarafdar; A Taranenko; P Tarján; H Themann; T L Thomas; M Togawa; A Toia; L Tomášek; H Torii; R S Towell; I Tserruya; Y Tsuchimoto; C Vale; H Valle; H W van Hecke; E Vazquez-Zambrano; A Veicht; J Velkovska; R Vértesi; A A Vinogradov; M Virius; V Vrba; E Vznuzdaev; X R Wang; D Watanabe; K Watanabe; Y Watanabe; F Wei; R Wei; J Wessels; S N White; D Winter; J P Wood; C L Woody; R M Wright; M Wysocki; W Xie; Y L Yamaguchi; K Yamaura; R Yang; A Yanovich; J Ying; S Yokkaichi; G R Young; I Younus; Z You; I E Yushmanov; W A Zajc; C Zhang; S Zhou; L Zolin; PHENIX Collaboration

doi:10.1103/PhysRevLett.105.142301

Azimuthal anisotropy of π⁰ production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry

Phys Rev Lett. 2010 Oct 1;105(14):142301. doi: 10.1103/PhysRevLett.105.142301. Epub 2010 Sep 27.

Authors

A Adare¹, S Afanasiev, C Aidala, N N Ajitanand, Y Akiba, H Al-Bataineh, J Alexander, K Aoki, Y Aramaki, E T Atomssa, R Averbeck, T C Awes, B Azmoun, V Babintsev, M Bai, G Baksay, L Baksay, K N Barish, B Bassalleck, A T Basye, S Bathe, V Baublis, C Baumann, A Bazilevsky, S Belikov, R Belmont, R Bennett, A Berdnikov, Y Berdnikov, A A Bickley, J S Bok, K Boyle, M L Brooks, H Buesching, V Bumazhnov, G Bunce, S Butsyk, C M Camacho, S Campbell, C-H Chen, C Y Chi, M Chiu, I J Choi, R K Choudhury, P Christiansen, T Chujo, P Chung, O Chvala, V Cianciolo, Z Citron, B A Cole, M Connors, P Constantin, M Csanád, T Csörgo, T Dahms, S Dairaku, I Danchev, K Das, A Datta, G David, A Denisov, A Deshpande, E J Desmond, O Dietzsch, A Dion, M Donadelli, O Drapier, A Drees, K A Drees, J M Durham, A Durum, D Dutta, S Edwards, Y V Efremenko, F Ellinghaus, T Engelmore, A Enokizono, H En'yo, S Esumi, B Fadem, D E Fields, M Finger Jr, M Finger, F Fleuret, S L Fokin, Z Fraenkel, J E Frantz, A Franz, A D Frawley, K Fujiwara, Y Fukao, T Fusayasu, I Garishvili, A Glenn, H Gong, M Gonin, Y Goto, R Granier de Cassagnac, N Grau, S V Greene, M Grosse Perdekamp, T Gunji, H-Å Gustafsson, J S Haggerty, K I Hahn, H Hamagaki, J Hamblen, J Hanks, R Han, E P Hartouni, E Haslum, R Hayano, M Heffner, S Hegyi, T K Hemmick, T Hester, X He, J C Hill, M Hohlmann, W Holzmann, K Homma, B Hong, T Horaguchi, D Hornback, S Huang, T Ichihara, R Ichimiya, J Ide, Y Ikeda, K Imai, M Inaba, D Isenhower, M Ishihara, T Isobe, M Issah, A Isupov, D Ivanischev, B V Jacak, J Jia, J Jin, B M Johnson, K S Joo, D Jouan, D S Jumper, F Kajihara, S Kametani, N Kamihara, J Kamin, J H Kang, J Kapustinsky, K Karatsu, D Kawall, M Kawashima, A V Kazantsev, T Kempel, A Khanzadeev, K M Kijima, B I Kim, D H Kim, D J Kim, E J Kim, E Kim, S H Kim, Y J Kim, E Kinney, K Kiriluk, A Kiss, E Kistenev, L Kochenda, B Komkov, M Konno, J Koster, D Kotchetkov, A Kozlov, A Král, A Kravitz, G J Kunde, K Kurita, M Kurosawa, Y Kwon, G S Kyle, R Lacey, Y S Lai, J G Lajoie, A Lebedev, D M Lee, J Lee, K B Lee, K Lee, K S Lee, M J Leitch, M A L Leite, E Leitner, B Lenzi, P Liebing, L A Linden Levy, T Liška, A Litvinenko, H Liu, M X Liu, X Li, B Love, R Luechtenborg, D Lynch, C F Maguire, Y I Makdisi, A Malakhov, M D Malik, V I Manko, E Mannel, Y Mao, H Masui, F Matathias, M McCumber, P L McGaughey, N Means, B Meredith, Y Miake, A C Mignerey, P Mikeš, K Miki, A Milov, M Mishra, J T Mitchell, A K Mohanty, Y Morino, A Morreale, D P Morrison, T V Moukhanova, J Murata, S Nagamiya, J L Nagle, M Naglis, M I Nagy, I Nakagawa, Y Nakamiya, T Nakamura, K Nakano, J Newby, M Nguyen, R Nouicer, A S Nyanin, E O'Brien, S X Oda, C A Ogilvie, K Okada, M Oka, Y Onuki, A Oskarsson, M Ouchida, K Ozawa, R Pak, V Pantuev, V Papavassiliou, I H Park, J Park, S K Park, W J Park, S F Pate, H Pei, J-C Peng, H Pereira, V Peresedov, D Yu Peressounko, C Pinkenburg, R P Pisani, M Proissl, M L Purschke, A K Purwar, H Qu, J Rak, A Rakotozafindrabe, I Ravinovich, K F Read, K Reygers, V Riabov, Y Riabov, E Richardson, D Roach, G Roche, S D Rolnick, M Rosati, C A Rosen, S S E Rosendahl, P Rosnet, P Rukoyatkin, P Ružička, B Sahlmueller, N Saito, T Sakaguchi, K Sakashita, V Samsonov, S Sano, T Sato, S Sawada, K Sedgwick, J Seele, R Seidl, A Yu Semenov, R Seto, D Sharma, I Shein, T-A Shibata, K Shigaki, M Shimomura, K Shoji, P Shukla, A Sickles, C L Silva, D Silvermyr, C Silvestre, K S Sim, B K Singh, C P Singh, V Singh, M Slunečka, R A Soltz, W E Sondheim, S P Sorensen, I V Sourikova, N A Sparks, P W Stankus, E Stenlund, S P Stoll, T Sugitate, A Sukhanov, J Sziklai, E M Takagui, A Taketani, R Tanabe, Y Tanaka, K Tanida, M J Tannenbaum, S Tarafdar, A Taranenko, P Tarján, H Themann, T L Thomas, M Togawa, A Toia, L Tomášek, H Torii, R S Towell, I Tserruya, Y Tsuchimoto, C Vale, H Valle, H W van Hecke, E Vazquez-Zambrano, A Veicht, J Velkovska, R Vértesi, A A Vinogradov, M Virius, V Vrba, E Vznuzdaev, X R Wang, D Watanabe, K Watanabe, Y Watanabe, F Wei, R Wei, J Wessels, S N White, D Winter, J P Wood, C L Woody, R M Wright, M Wysocki, W Xie, Y L Yamaguchi, K Yamaura, R Yang, A Yanovich, J Ying, S Yokkaichi, G R Young, I Younus, Z You, I E Yushmanov, W A Zajc, C Zhang, S Zhou, L Zolin; PHENIX Collaboration

Affiliation

¹ University of Colorado, Boulder, Colorado 80309, USA.

PMID: 21230825
DOI: 10.1103/PhysRevLett.105.142301

Abstract

We have measured the azimuthal anisotropy of π⁰ production for 1<p(T)<18 GeV/c for Au+Au collisions at sqrt((s)NN)=200 GeV. The observed anisotropy shows a gradual decrease for 3≲p(T)≲7-10 GeV/c, but remains positive beyond 10 GeV/c. The magnitude of this anisotropy is underpredicted, up to at least ∼10 GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.