D. E. Fields

Heavy-quark production in p plus p and energy loss and flow of heavy quarks in Au plus Au collisions at root s(NN)=200 GeV

Transverse momentum spectra of electrons (p(T)(e)) from semileptonic weak decays of heavy-flavor mesons in the range of 0.3 < p(T)(e) < 9.0 GeV/c have been measured at midrapidity (|y| < 0.35) by the PHENIX experiment at the Relativistic Heavy Ion Collider in p + p and Au + Au collisions at root s(NN) = 200 GeV. In addition, the azimuthal anisotropy parameter v(2) has been measured for 0.3 < p(T)(e) < 5.0 GeV/c in Au + Au collisions. The substantial modification in the p(T)(e) spectra in Au + Au compared with p + p collisions as well as the nonzero v(2) indicate substantial interactions and flow of heavy quarks in traversing the produced medium. Comparisons of these observables with detailed theoretical calculations can be used to identify the nature of these interactions and to quantify their extent. Disciplines Nuclear | Physics Comments This is an article from Physical Review C 84 (2011): 044905-1, doi:10.1103/PhysRevC.84.044905. Posted with permission. Authors Andrew Adare, Sergey Belikov, Paul Constantin, Nathan C. Grau, John C. Hill, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Jan Rak, Marzia Rosati, S. Skutnik, Carla Vale, et al., and PHENIX Collaboration This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/physastro_pubs/281 PHYSICAL REVIEW C 84, 044905 (2011) Heavy-quark production in p + p and energy loss and flow of heavy quarks in Au + Au collisions at √ sN N = 200 GeV A. Adare,9 S. Afanasiev,24 C. Aidala,10 N. N. Ajitanand,51 Y. Akiba,45,46 H. Al-Bataineh,40 J. Alexander,51 A. Al-Jamel,40 K. Aoki,30,45 L. Aphecetche,53 R. Armendariz,40 S. H. Aronson,4 J. Asai,46 E. T. Atomssa,31 R. Averbeck,52 T. C. Awes,41 B. Azmoun,4 V. Babintsev,19 G. Baksay,15 L. Baksay,15 A. Baldisseri,12 K. N. Barish,5 P. D. Barnes,33,* B. Bassalleck,39 S. Bathe,5 S. Batsouli,10,41 V. Baublis,44 F. Bauer,5 A. Bazilevsky,4 S. Belikov,4,23,* R. Bennett,52 Y. Berdnikov,48 A. A. Bickley,9 M. T. Bjorndal,10 J. G. Boissevain,33 H. Borel,12 K. Boyle,52 M. L. Brooks,33 D. S. Brown,40 D. Bucher,36 H. Buesching,4 V. Bumazhnov,19 G. Bunce,4,46 J. M. Burward-Hoy,33 S. Butsyk,33,52 S. Campbell,52 J.-S. Chai,25 B. S. Chang,60 J.-L. Charvet,12 S. Chernichenko,19 J. Chiba,26 C. Y. Chi,10 M. Chiu,10,20 I. J. Choi,60 T. Chujo,57 P. Chung,51 A. Churyn,19 V. Cianciolo,41 C. R. Cleven,17 Y. Cobigo,12 B. A. Cole,10 M. P. Comets,42 P. Constantin,23,33 M. Csanád,14 T. Csörgő,27 T. Dahms,52 K. Das,16 G. David,4 M. B. Deaton,1 K. Dehmelt,15 H. Delagrange,53 A. Denisov,19 D. d’Enterria,10 A. Deshpande,46,52 E. J. Desmond,4 O. Dietzsch,49 A. Dion,52 M. Donadelli,49 J. L. Drachenberg,1 O. Drapier,31 A. Drees,52 A. K. Dubey,59 A. Durum,19 V. Dzhordzhadze,5,54 Y. V. Efremenko,41 J. Egdemir,52 F. Ellinghaus,9 W. S. Emam,5 A. Enokizono,18,32 H. En’yo,45,46 B. Espagnon,42 S. Esumi,56 K. O. Eyser,5 D. E. Fields,39,46 M. Finger Jr.,6,24 M. Finger,6,24 F. Fleuret,31 S. L. Fokin,29 B. Forestier,34 Z. Fraenkel,59,* J. E. Frantz,10,52 A. Franz,4 A. D. Frawley,16 K. Fujiwara,45 Y. Fukao,30,45 S.-Y. Fung,5 T. Fusayasu,38 S. Gadrat,34 I. Garishvili,54 F. Gastineau,53 M. Germain,53 A. Glenn,9,54 H. Gong,52 M. Gonin,31 J. Gosset,12 Y. Goto,45,46 R. Granier de Cassagnac,31 N. Grau,23 S. V. Greene,57 M. Grosse Perdekamp,20,46 T. Gunji,8 H.-Å. Gustafsson,35,* T. Hachiya,18,45 A. Hadj Henni,53 C. Haegemann,39 J. S. Haggerty,4 M. N. Hagiwara,1 H. Hamagaki,8 R. Han,43 H. Harada,18 E. P. Hartouni,32 K. Haruna,18 M. Harvey,4 E. Haslum,35 K. Hasuko,45 R. Hayano,8 M. Heffner,32 T. K. Hemmick,52 T. Hester,5 J. M. Heuser,45 X. He,17 H. Hiejima,20 J. C. Hill,23 R. Hobbs,39 M. Hohlmann,15 M. Holmes,57 W. Holzmann,51 K. Homma,18 B. Hong,28 T. Horaguchi,45,55 D. Hornback,54 M. G. Hur,25 T. Ichihara,45,46 H. Iinuma,30,45 K. Imai,30,45 M. Inaba,56 Y. Inoue,45,47 D. Isenhower,1 L. Isenhower,1 M. Ishihara,45 T. Isobe,8 M. Issah,51 A. Isupov,24 B. V. Jacak,52,† J. Jia,10 J. Jin,10 O. Jinnouchi,46 B. M. Johnson,4 K. S. Joo,37 D. Jouan,42 F. Kajihara,8,45 S. Kametani,8,58 N. Kamihara,45,55 J. Kamin,52 M. Kaneta,46 J. H. Kang,60 H. Kanou,45,55 T. Kawagishi,56 D. Kawall,46 A. V. Kazantsev,29 S. Kelly,9 A. Khanzadeev,44 J. Kikuchi,58 D. H. Kim,37 D. J. Kim,60 E. Kim,50 Y.-S. Kim,25 E. Kinney,9 Á. Kiss,14 E. Kistenev,4 A. Kiyomichi,45 J. Klay,32 C. Klein-Boesing,36 L. Kochenda,44 V. Kochetkov,19 B. Komkov,44 M. Konno,56 D. Kotchetkov,5 A. Kozlov,59 A. Král,11 A. Kravitz,10 P. J. Kroon,4 J. Kubart,6,22 G. J. Kunde,33 N. Kurihara,8 K. Kurita,45,47 M. J. Kweon,28 Y. Kwon,54,60 G. S. Kyle,40 R. Lacey,51 Y. S. Lai,10 J. G. Lajoie,23 A. Lebedev,23 Y. Le Bornec,42 S. Leckey,52 D. M. Lee,33 M. K. Lee,60 T. Lee,50 M. J. Leitch,33 M. A. L. Leite,49 B. Lenzi,49 H. Lim,50 T. Liška,11 A. Litvinenko,24 M. X. Liu,33 X. Li,7 X. H. Li,5 B. Love,57 D. Lynch,4 C. F. Maguire,57 Y. I. Makdisi,3,4 A. Malakhov,24 M. D. Malik,39 V. I. Manko,29 Y. Mao,43,45 L. Mašek,6,22 H. Masui,56 F. Matathias,10,52 M. C. McCain,20 M. McCumber,52 P. L. McGaughey,33 Y. Miake,56 P. Mikeš,6,22 K. Miki,45,56 T. E. Miller,57 A. Milov,52 S. Mioduszewski,4 G. C. Mishra,17 M. Mishra,2 J. T. Mitchell,4 M. Mitrovski,51 A. Morreale,5 D. P. Morrison,4 J. M. Moss,33 T. V. Moukhanova,29 D. Mukhopadhyay,57 J. Murata,45,47 S. Nagamiya,26 Y. Nagata,56 J. L. Nagle,9 M. Naglis,59 I. Nakagawa,45,46 Y. Nakamiya,18 T. Nakamura,18 K. Nakano,45,55 J. Newby,32 M. Nguyen,52 B. E. Norman,33 R. Nouicer,4 A. S. Nyanin,29 J. Nystrand,35 E. O’Brien,4 S. X. Oda,8 C. A. Ogilvie,23 H. Ohnishi,45 I. D. Ojha,57 K. Okada,46 M. Oka,56 O. O. Omiwade,1 A. Oskarsson,35 I. Otterlund,35 M. Ouchida,18,45 K. Ozawa,8 R. Pak,4 D. Pal,57 A. P. T. Palounek,33 V. Pantuev,21,52 V. Papavassiliou,40 J. Park,50 W. J. Park,28 S. F. Pate,40 H. Pei,23 J.-C. Peng,20 H. Pereira,12 V. Peresedov,24 D. Yu. Peressounko,29 C. Pinkenburg,4 R. P. Pisani,4 M. L. Purschke,4 A. K. Purwar,33,52 H. Qu,17 J. Rak,23,39 A. Rakotozafindrabe,31 I. Ravinovich,59 K. F. Read,41,54 S. Rembeczki,15 M. Reuter,52 K. Reygers,36 V. Riabov,44 Y. Riabov,44 G. Roche,34 A. Romana,31,* M. Rosati,23 S. S. E. Rosendahl,35 P. Rosnet,34 P. Rukoyatkin,24 V. L. Rykov,45 S. S. Ryu,60 B. Sahlmueller,36 N. Saito,30,45,46 T. Sakaguchi,4,8,58 S. Sakai,56 H. Sakata,18 V. Samsonov,44 H. D. Sato,30,45 S. Sato,4,26,56 S. Sawada,26 J. Seele,9 R. Seidl,20 V. Semenov,19 R. Seto,5 D. Sharma,59 T. K. Shea,4 I. Shein,19 A. Shevel,44,51 T.-A. Shibata,45,55 K. Shigaki,18 M. Shimomura,56 T. Shohjoh,56 K. Shoji,30,45 A. Sickles,52 C. L. Silva,49 D. Silvermyr,41 C. Silvestre,12 K. S. Sim,28 C. P. Singh,2 V. Singh,2 S. Skutnik,23 M. Slunečka,6,24 W. C. Smith,1 A. Soldatov,19 R. A. Soltz,32 W. E. Sondheim,33 S. P. Sorensen,54 I. V. Sourikova,4 F. Staley,12 P. W. Stankus,41 E. Stenlund,35 M. Stepanov,40 A. Ster,27 S. P. Stoll,4 T. Sugitate,18 C. Suire,42 J. P. Sullivan,33 J. Sziklai,27 T. Tabaru,46 S. Takagi,56 E. M. Takagui,49 A. Taketani,45,46 K. H. Tanaka,26 Y. Tanaka,38 K. Tanida,45,46,50 M. J. Tannenbaum,4 A. Taranenko,51 P. Tarján,13 T. L. Thomas,39 M. Togawa,30,45 A. Toia,52 J. Tojo,45 L. Tomášek,22 H. Torii,45 R. S. Towell,1 V.-N. Tram,31 I. Tserruya,59 Y. Tsuchimoto,18,45 S. K. Tuli,2,* H. Tydesjö,35 N. Tyurin,19 C. Vale,23 H. Valle,57 H. W. van Hecke,33 J. Velkovska,57 R. Vértesi,13 A. A. Vinogradov,29 M. Virius,11 V. Vrba,22 E. Vznuzdaev,44 M. Wagner,30,45 D. Walker,52 X. R. Wang,40 Y. Watanabe,45,46 J. Wessels,36 S. N. White,4 N. Willis,42 D. Winter,10 C. L. Woody,4 M. Wysocki,9 W. Xie,5,46 Y. L. Yamaguchi,58 A. Yanovich,19 Z. Yasin,5 J. Ying,17 S. Yokkaichi,45,46 G. R. Young,41 I. Younus,39 I. E. Yushmanov,29 W. A. Zajc,10 O. Zaudtke,36 C. Zhang,10,41 S. Zhou,7 J. Zimányi,27,* and L. Zolin24 (PHENIX Collaboration) 044905-1 0556-2813/2011/84(4)/044905(42) ©2011 American Physical Society A. ADARE et al. PHYSICAL REVIEW C 84, 044905 (2011) 1Abilene Christian University, Abilene, Texas 79699, USA 2Department of Physics, Banaras Hindu University, Varanasi 221005, India 3Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA 4Brookhaven National Laboratory, Upton, New York 11973-5000, USA 5University of California-Riverside, Riverside, California 92521, USA 6Charles University, Ovocný trh 5, Praha 1, 116 36, Prague, Czech Republic 7Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413, People’s Republic of China 8Center for Nuclear Study, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan 9University of Colorado, Boulder, Colorado 80309, USA 10Columbia University, New York, New York 10027 and Nevis Laboratories, Irvington, New York 10533, USA 11Czech Technical University, Zikova 4, 166 36 Prague 6, Czech Republic 12Dapnia, CEA Saclay, F-91191, Gif-sur-Yvette, France 13Debrecen University, H-4010 Debrecen, Egyetem tér 1, Hungary 14ELTE, Eötvös Loránd University, H-1117 Budapest, Pázmány P. s. 1/A, Hungary 15Florida Institute of Technology, Melbourne, Florida 32901, USA 16Florida State University, Tallahassee, Florida 32306, USA 17Georgia State University, Atlanta, Georgia 30303, USA 18Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan 19IHEP Protvino, State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, 142281, Russia 20University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA 21Institute for Nuclear Research of the Russian Academy of Sciences, Prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia 22Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic 23Iowa State University, Ames, Iowa 50011, USA 24Joint Institute for Nuclear Research, Dubna, Moscow Region, 141980, Russia 25KAERI, Cyclotron Application Laboratory, Seoul, Korea 26KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan 27KFKI Research Institute for Particle and Nuclear Physics of the Hungarian Academy of Sciences (MTA KFKI RMKI), H-1525 Buda

Measurements of Higher-Order Flow Harmonics in Au+Au Collisions at

Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

\sqrt{s_{NN}} = 200

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200  GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

GeV

We present measured J/psi production rates in d + Au collisions at root s(NN) = 200 GeV over broad ranges of transverse momentum (p(T) = 0-14 GeV/c) and rapidity (-2.2 1) for p(T) > 2 GeV/c. The observed enhancement at negative rapidity has implications for the interpretation of the observed modification in heavy-ion collisions at high p(T). DOI: 10.1103/PhysRevC.87.034904

Cold Nuclear Matter Effects on J/psi Yields as a Function of Rapidity and Nuclear Geometry in d plus A Collisions at root S-NN=200 GeV

Abstract Proton distributions at mid-rapidity (2 ≤ y ≤ 3) have been measured for 158A·GeV Pb+Pb collisions in the focusing spectrometer experiment NA44 at CERN. From baryon number conservation and by comparing the experimentally measured d N d y distribution with the transport model RQMD, we conclude that a rather high degree of nuclear stopping has been reached for the truly heavy-ion collisions at these energies. Transverse mass distributions exhibit characteristically thermal shapes and the slope parameters increase with the mass of the colliding system.

Transverse-momentum dependence of the J/psi nuclear modification in d+Au collisions at root s(NN)=200 GeV

Abstract In the past, detectors using silica aerogel as a Cherenkov radiator treated this material as a diffuse source of Cherenkov photons. In this paper we report on measurements made to explore the feasibility of using aerogel for imaging Cherenkov purposes. The results of the measurements are reproduced by a detailed Monte Carlo. This allows us to identify parameters critical for the use of aerogel as a radiator in imaging detectors. We conclude that commercially available aerogel can be used for these purposes.

Mid-rapidity protons in 158A·GeV Pb+Pb collisions

Excitation functions have been measured for Z=3–12 fragments emitted in 14N+Ag and 14N+Au collisions and energies EA=20–50 MeV. With increasing bombarding energy, non-equilibriumemission processes grow in importance, dominating the fragment cross section at EA=50 MeV.

Use of aerogel for imaging Cherenkov counters

Abstract The NA44 Collaboration has measured yields and differential distributions of K + , K − , π + , π − in transverse kinetic energy and rapidity, around the center-of-mass rapidity in 158 A GeV/ c Pb+Pb collisions at the CERN SPS. A considerable enhancement of K + production per π is observed, as compared to p + p collisions at this energy. To illustrate the importance of secondary hadron rescattering as an enhancement mechanism, we compare strangeness production at the SPS and AGS with predictions of the transport model RQMD.The NA44 Collaboration has measured yields and differential distributions of K+, K-, pi+, pi- in transverse kinetic energy and rapidity, around the center-of-mass rapidity in 158 A GeV/c Pb+Pb collisions at the CERN SPS. A considerable enhancement of K+ production per pi is observed, as compared to p+p collisions at this energy. To illustrate the importance of secondary hadron rescattering as an enhancement mechanism, we compare strangeness production at the SPS and AGS with predictions of the transport model RQMD.

Non-equilibrium versus equilibrium emission of complex fragments emitted in 14N induced reactions on Ag and Au at EA=20–50 MeV☆

Abstract π−π−π− correlations from Pb+Pb collisions at 158 GeV/c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for Pb+Pb than for S+Pb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension.

Strange meson enhancement in PbPb collisions

Experiment NA44 has measured proton and antiproton distributions at mid-rapidity in sulphur and proton collisions with nuclear targets at 200 and 450 GeV/c per nucleon respectively. The inverse slopes of transverse mass distributions increase with system size for both protons and antiprotons but are slightly lower for antiprotons. This could happen if antiprotons are annihilated in the nuclear medium. The antiproton yield increases with system size and centrality and is largest at mid-rapidity. The proton yield also increases with system size and centrality, but decreases from backward rapidity to mid-rapidity. The stopping of protons at these energies lies between the full stopping and nuclear transparency scenarios. The data are in reasonable agreement with RQMD predictions except for the antiproton yields from sulphur-nucleus collisions. PACS numbers: 25.75.-q 13.85.-t 13.60.Rj Typeset using REVTEX 2