High-momentum two-particle correlations are a useful tool for studying jet-quenching effects in the quark-gluon plasma. Angular correlations between neutral-pion triggers and charged hadrons with transverse momenta in the range 4–12 GeV/c and 0.5–7 GeV/c, respectively, have been measured by the PHENIX experiment in 2014 for Au+Au collisions at √(s__NN)=200 GeV. Suppression is observed in the yield of high-momentum jet fragments opposite the trigger particle, which indicates jet suppression stemming from in-medium partonic energy loss, while enhancement is observed for low-momentum particles. The ratio and differences between the yield in Au+Au collisions and p+p collisions, I_AA and Δ_AA, as a function of the trigger-hadron azimuthal separation, Δϕ, are measured for the first time at the Relativistic Heavy Ion Collider. These results better quantify how the yield of low-p_T associated hadrons is enhanced at wide angle, which is crucial for studying energy loss as well as medium-response effects.

High-momentum two-particle correlations are a useful tool for studying jet-quenching effects in the quarkgluon plasma. Angular correlations between neutral-pion triggers and charged hadrons with transverse momenta in the range 4-12 GeV/c and 0.5-7 GeV/c, respectively, have been measured by the PHENIX experiment in 2014 for Au + Au collisions at root sNN = 200 GeV. Suppression is observed in the yield of high-momentum jet fragments opposite the trigger particle, which indicates jet suppression stemming from in-medium partonic energy loss, while enhancement is observed for low-momentum particles. The ratio and differences between the yield in Au + Au collisions and p + p collisions, I-AA and Delta(AA), as a function of the trigger-hadron azimuthal separation, Delta phi, are measured for the first time at the BNL Relativistic Heavy Ion Collider. These results better quantify how the yield of low-pT associated hadrons is enhanced at wide angle, which is crucial for studying energy loss as well as medium-response effects.

We present direct photon-hadron correlations in 200 GeV/A Au + Au, d + Au, and p + p collisions, for direct photon p(T) from 5-12 GeV/c, collected by the PHENIX Collaboration in the years from 2006 to 2011. We observe no significant modification of jet fragmentation in d + Au collisions, indicating that cold nuclear matter effects are small or absent. Hadrons carrying a large fraction of the quark's momentum are suppressed in Au + Au compared to p + p and d + Au. As the momentum fraction decreases, the yield of hadrons in Au + Au increases to an excess over the yield in p + p collisions. The excess is at large angles and at low hadron p(T) and is most pronounced for hadrons associated with lower momentum direct photons. Comparison to theoretical calculations suggests that the hadron excess arises from medium response to energy deposited by jets.

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Experimental results at RHIC and at the LHC show a similar strong suppression for light and heavy quark probes at high pT, and a possible quark mass dependence of suppression at low pT. More high precision measurements of separated charm and bottom are needed to quantify the dependence of medium effects on the quark mass. The PHENIX experiment measured separated electrons from bottom and charm decays using displaced vertex distributions at mid-rapidity |y|<0.35. Azimuthal anisotropy of electrons from separated charm and bottom decays are obtained from high statistics Au+Au data taken in 2014. PHENIX also measures muons from heavy quark decays in d+Au collisions at forward rapidity to study collective effects on heavy flavor production in small systems. These proceedings report the azimuthal anisotropy of charm and bottom at mid-rapidity in minimum bias Au+Au collisions and the anisotropy of single muons from heavy quark decays in d+Au collisions.

Using the extraordinary versatility of RHIC in selecting different colliding species, the PHENIX experiment has collected data in p+Al, p+Au, d+Au, and He-3+Au collisions at 200 GeV center-of-mass energy and conducted a comprehensive set of anisotropic flow measurements. These geometry-controlled experiments provide a unique testing ground for theoretical models that produce azimuthal particle correlations based on initial- and/or final-state effects. A complete set of triangular anisotropies of inclusive charged particles and final results on identified pion and proton v(2)(p(T)) are shown. The mass-ordered splitting in v(2)(p(T)) provides information about the role of early-stage collective flow and late-stage hadronic rescattering. Detailed model comparisons with all observables are discussed.

We present measurements of azimuthal correlations of charged hadron pairs in sNN=200 GeV Au+Au collisions for the trigger and associated particle transverse-momentum ranges of 14GeV/c) correlations is suppressed compared with that of correlations measured in p+p collisions. At the lowest associated particle pT(0.5

Dilepton spectra are a classic probe to study ultra-relativistic heavy ion collisions. At RHIC energies, the dimuon continuum is dominated by correlated pairs from semi-leptonic decays of charm and bottom hadrons and the Drell-Yan process. The dimuon spectra contain information on heavy flavor angular correlations, which can constrain the relative contributions from different heavy flavor production mechanisms. Studying heavy flavor correlations in p+Au collisions may provide further insight on cold nuclear matter effects. Measurements of the Drell-Yan cross-section can provide constraints to PDFs, as well as further our understanding in initial state interactions in p+Au collisions. In this talk, we report measurements of pp pairs from charm, bottom, and Drell-Yan in p+p and p+Au collisions at root S-NN = 200 GeV. A further shape analysis is applied to the heavy flavor pair correlations to extract the relative contributions to heavy flavor production mechanisms.

Forward hadron measurements in p(d)+A provide a signal to study nuclear shadowing, initial state energy loss and/or gluon saturation effects as a function of rapidity, centrality and energy. High p(T) identified pi(0) measurements are an essential first step toward measuring prompt photon production. The pi(0) measurements are enabled by the PHENIX MPC-EX detector, a Si-W preshower detector located in front of the Muon Piston Calorimeter (MPC), expanding the neutral pion reconstruction capabilities in the rapidity range 3.1 < eta < 3.8 out to high energies, E < 80 GeV. Previous PHENIX measurements of punch-through charged hadrons in the muon arms in the rapidity range 1.4 < vertical bar eta vertical bar < 2.2 were significantly improved through the capability of the forward silicon vertex detector (FVTX) to determine the transverse momentum and rapidity with high precision and reject background from secondary hadrons. PHENIX collected d+Au data with the MPC-EX in the 2016 run at root s(NN) = 200, 62, 39 and 19.6 GeV; and p+p and p+Au(Al) data with the FVTX in 2015 at 200 GeV. In this talk, we will present first results for high p(T) pi(0) production from the root s(NN) = 200 GeV dataset, the status of the prompt photon measurement, as well as charged hadron nuclear modification factors in p+Au(Al) and He-3+Au.

Detailed measurements of collectivity in Au+Au collisions at RHIC provide a key connection between the initial geometry of the deposited energy and the hydrodynamic evolution of the medium created in heavy-ion collisions. Utilizing the highly segmented PHENIX inner trackers, we present new measurements of flow coefficients extending over a wide range in pseudorapidity 1 < |η| < 3 and pT. Over a centrality range of 0-90%, we present cumulant results v2{2} −v2{8} and v3{2} as well as quantifying the event-by-event flow fluctuations. Complementing these results, we measure event-by-event v2 and v3 distributions using an unfolding procedure.

The PHENIX experiment has excellent data for small systems including p+Au, d+Au, He-3+Au at 200 GeV as well as the d+Au beam energy scan down to 19.6 GeV. We present new measurements of dN(ch)/d eta for all of these systems over a broad range in pseudorapidity -3 < eta < +3 and event multiplicity. These measurements provide key constraints of baryon stopping models and are compared with various theoretical calculations. The measurements are also compared with flow observables as a function of pseudorapidity to explore scaling relations. In particular measurements as a function of collision energy provide key inputs for calculations for the upcoming A+A beam energy scan at RHIC in terms of particle production and baryon rapidity shifts.

Proton-nucleus (p+A) collisions play an important role as a control system for interpreting hot nuclear matter effects in nucleus-nucleus (A+A) collisions. There is a large amount of data from both RHIC and the LHC that indicate that collective effects are also present in small systems. Understanding the origin of these effects is still incomplete, since a variety of models with very different underlying physics have been shown to describe p+A data. We present a comprehensive set of measurements of soft-physics observables and comparisons with theoretical models. These measurements include multi-particle correlations as a function of event multiplicity, ν2(pT) and ν3(pT) for inclusive charged particles at mid-rapidity, ν2(pT) for hadrons at forward/backward rapidities, and the centrality and pseudorapidity dependence of inclusive ν2. The implications for the origin of collectivity in p+Au collisions at RHIC is discussed.

We measured direct photons for pT<5GeV/c in minimum bias and 0%–40% most-central events at midrapidity for Cu+Cu collisions at √sNN=200GeV. The e+e− contribution from quasireal direct virtual photons has been determined as an excess over the known hadronic contributions in the e+e− mass distribution. A clear enhancement of photons over the binary scaled p+p fit is observed for pT<4GeV/c in Cu+Cu data. The pT spectra are consistent with the Au+Au data covering a similar number of participants. The inverse slopes of the exponential fits to the excess after subtraction of the p+p baseline are 285±53(stat)±57(syst)MeV/c and 333±72(stat)±45(syst)MeV/c for minimum bias and 0%–40% most-central events, respectively. The rapidity density, dN/dy, of photons demonstrates the same power law as a function of dNch/dη observed in Au+Au at the same collision energy. (Less)

We report on the first measurement of the double-spin asymmetry, A(LL), of electrons from the decays of hadrons containing heavy flavor in longitudinally polarized p + p collisions at root s = 200 GeV for p(T) = 0.5 to 3.0 GeV/c. The asymmetry was measured at midrapidity (vertical bar eta vertical bar < 0.35) with the PHENIX detector at the Relativistic Heavy Ion Collider. The measured asymmetries are consistent with zero within the statistical errors. We obtained a constraint for the polarized gluon distribution in the proton of vertical bar Delta g/g(log(10)(x) = -1.6(-0.4)(+0.5), mu = m(T)(c)vertical bar(2) < 0.030 (1 sigma) based on a leading-order perturbative quantum chromodynamics model, using the measured asymmetry. Disciplines Elementary Particles and Fields and String Theory | Physics Comments This is an article from Physical Review D 87 (2013): 012011-1, doi:10.1103/PhysRevD.87.012011. Posted with permission. Authors Andrew Adare, Alan Dion, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Marzia Rosati, C. L. Silva, Feng Wei, et al., and PHENIX Collaboration This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/physastro_pubs/250 Double-spin asymmetry of electrons from heavy-flavor decays in p þp collisions at ffiffi s p 1⁄4 200 GeV A. Adare, S. Afanasiev, C. Aidala, N.N. Ajitanand, Y. Akiba, R. Akimoto, H. Al-Ta’ani, J. Alexander, K. R. Andrews, A. Angerami, K. Aoki, N. Apadula, E. Appelt, Y. Aramaki, R. Armendariz, E. C. Aschenauer, T. C. Awes, B. Azmoun, V. Babintsev, M. Bai, B. Bannier, K.N. Barish, B. Bassalleck, A. T. Basye, S. Bathe, V. Baublis, C. Baumann, A. Bazilevsky, R. Belmont, J. Ben-Benjamin, R. Bennett, A. Berdnikov, Y. Berdnikov, D. S. Blau, J. S. Bok, K. Boyle, M. L. Brooks, D. Broxmeyer, H. Buesching, V. Bumazhnov, G. Bunce, S. Butsyk, S. Campbell, P. Castera, C.-H. Chen, C. Y. Chi, M. Chiu, I. J. Choi, J. B. Choi, R.K. Choudhury, P. Christiansen, T. Chujo, O. Chvala, V. Cianciolo, Z. Citron, B. A. Cole, Z. Conesa del Valle, M. Connors, M. Csanád, T. Csörgő, S. Dairaku, A. Datta, G. David, M.K. Dayananda, A. Denisov, A. Deshpande, E. J. Desmond, K.V. Dharmawardane, O. Dietzsch, A. Dion, M. Donadelli, O. Drapier, A. Drees, K.A. Drees, J.M. Durham, A. Durum, L. D’Orazio, Y. V. Efremenko, T. Engelmore, A. Enokizono, H. En’yo, S. Esumi, B. Fadem, D. E. Fields, M. Finger, M. Finger, Jr., F. Fleuret, S. L. Fokin, J. E. Frantz, A. Franz, A.D. Frawley, Y. Fukao, T. Fusayasu, I. Garishvili, A. Glenn, X. Gong, M. Gonin, Y. Goto, R. Granier de Cassagnac, N. Grau, S. V. Greene, M. Grosse Perdekamp, T. Gunji, L. Guo, H.-Å. Gustafsson,* J. S. Haggerty, K. I. Hahn, H. Hamagaki, J. Hamblen, R. Han, J. Hanks, C. Harper, K. Hashimoto, E. Haslum, R. Hayano, X. He, T. K. Hemmick, T. Hester, J. C. Hill, R. S. Hollis, W. Holzmann, K. Homma, B. Hong, T. Horaguchi, Y. Hori, D. Hornback, S. Huang, T. Ichihara, R. Ichimiya, H. Iinuma, Y. Ikeda, K. Imai, M. Inaba, A. Iordanova, D. Isenhower, M. Ishihara, M. Issah, A. Isupov, D. Ivanischev, Y. Iwanaga, B.V. Jacak, J. Jia, X. Jiang, D. John, B.M. Johnson, T. Jones, K. S. Joo, D. Jouan, J. Kamin, S. Kaneti, B. H. Kang, J. H. Kang, J. S. Kang, J. Kapustinsky, K. Karatsu, M. Kasai, D. Kawall, A.V. Kazantsev, T. Kempel, A. Khanzadeev, K.M. Kijima, B. I. Kim, D. J. Kim, E.-J. Kim, Y.-J. Kim, Y.K. Kim, E. Kinney, Á. Kiss, E. Kistenev, D. Kleinjan, P. Kline, L. Kochenda, B. Komkov, M. Konno, J. Koster, D. Kotov, A. Král, 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. S. Lee, S. H. Lee, S. R. Lee, M. J. Leitch, M.A. L. Leite, X. Li, S. H. Lim, L. A. Linden Levy, A. Litvinenko, H. Liu, M.X. Liu, B. Love, D. Lynch, C. F. Maguire, Y. I. Makdisi, A. Malakhov, A. Manion, V. I. Manko, E. Mannel, Y. Mao, H. Masui, M. McCumber, P. L. McGaughey, D. McGlinchey, C. McKinney, N. Means, M. Mendoza, B. Meredith, Y. Miake, T. Mibe, A. C. Mignerey, K. Miki, A. Milov, J. T. Mitchell, Y. Miyachi, A.K. Mohanty, H. J. Moon, Y. Morino, A. Morreale, D. P. Morrison, S. Motschwiller, T. V. Moukhanova, T. Murakami, J. Murata, S. Nagamiya, J. L. Nagle, M. Naglis, M. I. Nagy, I. Nakagawa, Y. Nakamiya, K. R. Nakamura, T. Nakamura, K. Nakano, J. Newby, M. Nguyen, M. Nihashi, R. Nouicer, A. S. Nyanin, C. Oakley, E. O’Brien, C. A. Ogilvie, M. Oka, K. Okada, A. Oskarsson, M. Ouchida, K. Ozawa, R. Pak, V. Pantuev, V. Papavassiliou, B. H. Park, I. H. Park, S. K. Park, S. F. Pate, H. Pei, J.-C. Peng, H. Pereira, V. Peresedov, D.Yu. Peressounko, R. Petti, C. Pinkenburg, R. P. Pisani, M. Proissl, M. L. Purschke, H. Qu, J. Rak, I. Ravinovich, K. F. Read, K. Reygers, V. Riabov, Y. Riabov, E. Richardson, D. Roach, G. Roche, S. D. Rolnick, M. Rosati, S. S. E. Rosendahl, P. Rukoyatkin, B. Sahlmueller, N. Saito, T. Sakaguchi, V. Samsonov, S. Sano, M. Sarsour, T. Sato, M. Savastio, S. Sawada, K. Sedgwick, R. Seidl, R. Seto, D. Sharma, I. Shein, T.-A. Shibata, K. Shigaki, H.H. Shim, 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, T. Sodre, R. A. Soltz, W. E. Sondheim, S. P. Sorensen, I. V. Sourikova, P.W. Stankus, E. Stenlund, S. P. Stoll, T. Sugitate, A. Sukhanov, J. Sun, J. Sziklai, E.M. Takagui, A. Takahara, A. Taketani, R. Tanabe, Y. Tanaka, S. Taneja, K. Tanida, M. J. Tannenbaum, S. Tarafdar, A. Taranenko, E. Tennant, H. Themann, D. Thomas, M. Togawa, L. Tomášek, M. Tomášek, H. Torii, R. S. Towell, I. Tserruya, Y. Tsuchimoto, K. Utsunomiya, C. Vale, H.W. van Hecke, E. Vazquez-Zambrano, A. Veicht, J. Velkovska, R. Vértesi, M. Virius, A. Vossen, V. Vrba, E. Vznuzdaev, X. R. Wang, D. Watanabe, K. Watanabe, Y. Watanabe, Y. S. Watanabe, F. Wei, R. Wei, J. Wessels, S. N. White, D. Winter, C. L. Woody, R.M. Wright, M. Wysocki, Y. L. Yamaguchi, R. Yang, A. Yanovich, J. Ying, S. Yokkaichi, J. S. Yoo, Z. You, G. R. Young, I. Younus, I. E. Yushmanov, W.A. Zajc, A. Zelenski, S. Zhou, and L. Zolin PHYSICAL REVIEW D 87, 012011 (2013) 1550-7998=2013=87(1)=012011(17) 012011-1 2013 American Physical Society (PHENIX Collaboration) Abilene Christian University, Abilene, Texas 79699, USA Department of Physics, Banaras Hindu University, Varanasi 221005, India Bhabha Atomic Research Centre, Bombay 400 085, India Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA University of California Riverside, Riverside, California 92521, USA Charles University, Ovocný trh 5, Praha 1, 116 36, Prague, Czech Republic Chonbuk National University, Jeonju, 561-756, Korea Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413, People’s Republic of China Center for Nuclear Study, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan University of Colorado, Boulder, Colorado 80309, USA Columbia University, New York, New York 10027 and Nevis Laboratories, Irvington, New York 10533, USA Czech Technical University, Zikova 4, 166 36 Prague 6, Czech Republic Dapnia, CEA Saclay, F-91191, Gif-sur-Yvette, France ELTE, Eötvös Loránd University, H 1117 Budapest, Pázmány P. s. 1/A, Hungary Ewha Womans University, Seoul 120-750, Korea Florida State University, Tallahassee, Florida 32306, USA Georgia State University, Atlanta, Georgia 30303, USA Hanyang University, Seoul 133-792, Korea Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan IHEP Protvino, State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, 142281, Russia University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic Iowa State University, Ames, Iowa 50011, USA Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia Helsinki Institute of Physics and University of Jyväskylä, P.O. Box 35, FI-40014 Jyväskylä, Finland KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan Korea University, Seoul, 136-701, Korea Russian Research Center ‘‘Kurchatov Institute’’, Moscow, 123098 Russia Kyoto University, Kyoto 606-8502, Japan Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS-IN2P3, Route de Saclay, F-91128, Palaiseau, France Lawrence Livermore National Laboratory, Livermore, California 94550, USA Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA LPC, Université Blaise Pascal, CNRS-IN2P3, Clermont-Fd, 63177 Aubiere Cedex, France Department of Physics, Lund University, P.O. Box 118, SE-221 00 Lund, Sweden University of Maryland, College Park, Maryland 20742, USA Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337, USA Institut fur Kernphysik, University of Muenster, D-48149 Muenster, Germany Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA Myongji University, Yongin, Kyonggido 449-728, Korea Nagasaki Institute of Applied Science, Nagasaki-shi, Nagasaki 851-0193, Japan University of New Mexico, Albuquerque, New Mexico 87131, USA New Mexico State University, Las Cruces, New Mexico 88003, USA Department of Physics and Astronomy, Ohio University, Athens, Ohio 45701, USA Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, BP1, F-91406, Orsay, France Peking University, Beijing 100871, People’s Republic of China PNPI, Petersburg Nuclear Physics Institute, Gatchina, Leningrad region, 188300, Russia RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973-5000, USA Physics Departmen

We report the measurement of the transverse momentum dependence of inclusive J/psi polarization in p + p collisions at root s = 200 GeV performed by the PHENIX Experiment at the Relativistic Heavy Ion Collider. The J/psi polarization is studied in the helicity, Gottfried-Jackson, and Collins-Soper frames for p(T) < 5 GeV/c and vertical bar y vertical bar < 0.35. The polarization in the helicity and Gottfried-Jackson frames is consistent with zero for all transverse momenta, with a slight (1.8 sigma) trend towards longitudinal polarization for transverse momenta above 2 GeV/c. No conclusion is allowed due to the limited acceptance in the Collins-Soper frame and the uncertainties of the current data. The results are compared to observations for other collision systems and center of mass energies and to different quarkonia production models. Disciplines Elementary Particles and Fields and String Theory | Physics Comments This article is published as Adare, A., S. Afanasiev, C. Aidala, N. N. Ajitanand, Yasuyuki Akiba, H. Al-Bataineh, J. Alexander et al. "Transverse momentum dependence of J/ψ polarization at midrapidity in p+ p collisions at s= 200 GeV." Physical Review D 82, no. 1 (2010): 012001. DOI:10.1103/PhysRevD.82.012001. Posted with permission. Authors Andrew Adare, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Marzia Rosati, Alexey Yu. Semenov, Carla Vale, Feng Wei, et al., and PHENIX Collaboration This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/physastro_pubs/315 Transverse momentum dependence of J=c polarization at midrapidity in pþ p collisions at ffiffi s p 1⁄4 200 GeV A. Adare, S. Afanasiev, C. Aidala, N.N. Ajitanand, Y. Akiba, H. Al-Bataineh, J. Alexander, K. Aoki, L. Aphecetche, J. Asai, E. T. Atomssa, R. Averbeck, T. C. Awes, B. Azmoun, V. Babintsev, M. Bai, G. Baksay, L. Baksay, A. Baldisseri, K.N. Barish, P. D. Barnes, B. Bassalleck, A. T. Basye, S. Bathe, S. Batsouli, V. Baublis, C. Baumann, A. Bazilevsky, S. Belikov,* R. Bennett, A. Berdnikov, Y. Berdnikov, A. A. Bickley, J. G. Boissevain, H. Borel, K. Boyle, M. L. Brooks, H. Buesching, V. Bumazhnov, G. Bunce, S. Butsyk, C.M. Camacho, S. Campbell, B. S. Chang, W.C. Chang, J.-L. Charvet, S. Chernichenko, C.Y. Chi, M. Chiu, I. J. Choi, R. K. Choudhury, T. Chujo, P. Chung, A. Churyn, V. Cianciolo, Z. Citron, B. A. Cole, Z. Conesa del Valle, P. Constantin, M. Csanád, T. Csörgö, T. Dahms, S. Dairaku, K. Das, G. David, A. Denisov, D. d’Enterria, A. Deshpande, E. J. Desmond, O. Dietzsch, A. Dion, M. Donadelli, O. Drapier, A. Drees, K.A. Drees, A.K. Dubey, A. Durum, D. Dutta, V. Dzhordzhadze, Y. V. Efremenko, F. Ellinghaus, T. Engelmore, A. Enokizono, H. En’yo, S. Esumi, K. O. Eyser, 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, J. Gosset, Y. Goto, R. Granier de Cassagnac, N. Grau, S. V. Greene, M. Grosse Perdekamp, T. Gunji, H.-Å. Gustafsson, A. Hadj Henni, J. S. Haggerty, H. Hamagaki, R. Han, E. P. Hartouni, K. Haruna, E. Haslum, R. Hayano, M. Heffner, 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, Y. Ikeda, K. Imai, J. Imrek, M. Inaba, D. Isenhower, M. Ishihara, T. Isobe, M. Issah, A. Isupov, D. Ivanischev, B. V. Jacak,54,x J. Jia, J. Jin, B.M. Johnson, K. S. Joo, D. Jouan, F. Kajihara, S. Kametani, N. Kamihara, J. Kamin, J. H. Kang, J. Kapustinsky, D. Kawall, A.V. Kazantsev, T. Kempel, A. Khanzadeev, K.M. Kijima, J. Kikuchi, B. I. Kim, D.H. Kim, D. J. Kim, E. Kim, S. H. Kim, E. Kinney, K. Kiriluk, A. Kiss, E. Kistenev, J. Klay, C. Klein-Boesing, L. Kochenda, B. Komkov, M. Konno, J. Koster, A. Kozlov, A. Král, A. Kravitz, G. J. Kunde, K. Kurita, M. Kurosawa, M. J. Kweon, Y. Kwon, G. S. Kyle, R. Lacey, Y. S. Lai, J. G. Lajoie, D. Layton, A. Lebedev, D.M. Lee, K. B. Lee, T. Lee, M. J. Leitch, M.A. L. Leite, B. Lenzi, P. Liebing, T. Liška, A. Litvinenko, H. Liu, M.X. Liu, X. Li, B. Love, D. Lynch, C. F. Maguire, Y. I. Makdisi, A. Malakhov, M.D. Malik, V. I. Manko, E. Mannel, Y. Mao, L. Mašek, H. Masui, F. Matathias, M. McCumber, P. L. McGaughey, N. Means, B. Meredith, Y. Miake, P. Mikeš, K. Miki, A. Milov, M. Mishra, J. T. Mitchell, A. K. Mohanty, Y. Morino, A. Morreale, D. P. Morrison, T. V. Moukhanova, D. Mukhopadhyay, J. Murata, S. Nagamiya, J. L. Nagle, M. Naglis, M. I. Nagy, I. Nakagawa, Y. Nakamiya, T. Nakamura, K. Nakano, J. Newby, M. Nguyen, T. Niita, R. Nouicer, A. S. Nyanin, E. O’Brien, S. X. Oda, C.A. Ogilvie, H. Okada, K. Okada, M. Oka, Y. Onuki, A. Oskarsson, M. Ouchida, K. Ozawa, R. Pak, A. P. T. Palounek, V. Pantuev, V. Papavassiliou, J. Park, W. J. Park, S. F. Pate, H. Pei, J.-C. Peng, H. Pereira, V. Peresedov, D. Yu. Peressounko, C. Pinkenburg, M. L. Purschke, A. K. Purwar, H. Qu, J. Rak, A. Rakotozafindrabe, I. Ravinovich, K. F. Read, S. Rembeczki, K. Reygers, V. Riabov, Y. Riabov, D. Roach, G. Roche, S. D. Rolnick, M. Rosati, S. S. E. Rosendahl, P. Rosnet, P. Rukoyatkin, P. Ružička, V. L. Rykov, B. Sahlmueller, N. Saito, T. Sakaguchi, S. Sakai, K. Sakashita, V. Samsonov, T. Sato, S. Sawada, K. Sedgwick, J. Seele, R. Seidl, A.Yu. Semenov, V. 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, A. Soldatov, R. A. Soltz, W. E. Sondheim, S. P. Sorensen, I. V. Sourikova, F. Staley, P.W. Stankus, E. Stenlund, M. Stepanov, A. Ster, S. P. Stoll, T. Sugitate, C. Suire, A. Sukhanov, J. Sziklai, E.M. Takagui, A. Taketani, R. Tanabe, Y. Tanaka, K. Tanida, M. J. Tannenbaum, A. Taranenko, P. Tarján, H. Themann, T. L. Thomas, M. Togawa, A. Toia, L. Tomášek, Y. Tomita, H. Torii, R. S. Towell, V-N. Tram, I. Tserruya, Y. Tsuchimoto, C. Vale, H. Valle, H.W. van Hecke, A. Veicht, J. Velkovska, R. Vertesi, A.A. Vinogradov, M. Virius, V. Vrba, E. Vznuzdaev, X. R. Wang, Y. Watanabe, F. Wei, J. Wessels, S. N. White, D. Winter, C. L. Woody, M. Wysocki, W. Xie, Y. L. Yamaguchi, K. Yamaura, R. Yang, A. Yanovich, J. Ying, S. Yokkaichi, G. R. Young, I. Younus, I. E. Yushmanov, W.A. Zajc, O. Zaudtke, C. Zhang, S. Zhou, and L. Zolin PHYSICAL REVIEW D 82, 012001 (2010) 1550-7998=2010=82(1)=012001(10) 012001-1 2010 The American Physical Society (PHENIX Collaboration) Abilene Christian University, Abilene, Texas 79699, USA Institute of Physics, Academia Sinica, Taipei 11529, Taiwan Department of Physics, Banaras Hindu University, Varanasi 221005, India Bhabha Atomic Research Centre, Bombay 400 085, India Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA University of California-Riverside, Riverside, California 92521, USA Charles University, Ovocný trh 5, Praha 1, 116 36, Prague, Czech Republic China Institute of Atomic Energy (CIAE), Beijing, People’s Republic of China Center for Nuclear Study, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan University of Colorado, Boulder, Colorado 80309, USA Columbia University, New York, New York 10027, and Nevis Laboratories, Irvington, New York 10533, USA Czech Technical University, Zikova 4, 166 36 Prague 6, Czech Republic Dapnia, CEA Saclay, F-91191, Gif-sur-Yvette, France Debrecen University, H-4010 Debrecen, Egyetem tér 1, Hungary ELTE, Eötvös Loránd University, H-1117 Budapest, Pázmány P. s. 1/A, Hungary Florida Institute of Technology, Melbourne, Florida 32901, USA Florida State University, Tallahassee, Florida 32306, USA Georgia State University, Atlanta, Georgia 30303, USA Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan IHEP Protvino, State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, 142281, Russia University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic Iowa State University, Ames, Iowa 50011, USA Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan KFKI Research Institute for Particle and Nuclear Physics of the Hungarian Academy of Sciences (MTA KFKI RMKI), H-1525 Budapest 114, P.O. Box 49, Budapest, Hungary Korea University, Seoul 136-701, Korea Russian Research Center Kurchatov Institute, Moscow, Russia Kyoto University, Kyoto 606-8502, Japan Laboratoire Leprince-Ringuet, École Polytechnique, CNRS-IN2P3, Route de Saclay, F-91128, Palaiseau, France Lawrence Livermore National Laboratory, Livermore, California 94550, USA Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA LPC, Université Blaise Pascal, CNRS-IN2P3, Clermont-Fd, 63177 Aubiere Cedex, France Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337, USA Institut für Kernphysik, University of Muenster, D-48149 Muenster, Germany Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA Myongji University, Yongin, Kyonggido 449-728, Korea Nagasaki Institute of Applied Science, Nagasaki-shi, Nagasaki 851-0193, Japan University of New Mexico, Albuquerque, New Mexico 87131, USA New Mexico State University, Las Cruces, New Mexico 88003, USA Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, BP1, F-91406, Orsay, France Peking University, Beijing, People’s Republic of China PNPI, Petersburg Nuclear Physics Institute, Gatchina, Leningrad Region, 188300, Russia RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0

Unpolarized cross sections and double-helicity asymmetries of single-inclusive positive and negative charged hadrons at midrapidity from p + p collisions at root s = 62.4 GeV are presented. The PHENIX measurement of the cross sections for 1.0 < p(T) < 4.5 GeV/c are consistent with perturbative QCD calculations at next-toleading order in the strong-coupling constant, alpha(s). Resummed pQCD calculations including terms with next-to-leading-log accuracy, yielding reduced theoretical uncertainties, also agree with the data. The doublehelicity asymmetry, sensitive at leading order to the gluon polarization in a momentum-fraction range of 0.05 less than or similar to x(gluon) less than or similar to 0.2, is consistent with recent global parametrizations disfavoring large gluon polarization. Disciplines Elementary Particles and Fields and String Theory | Physics Comments This is an article from Physical Review D 86 (2012): 092006-1, doi:10.1103/PhysRevD.86.092006. Posted with permission. Authors Andrew Adare, John C. Hill, Todd Kempel, John G. Lajoie, Alexandre Lebedev, Craig Ogilvie, H. Pei, Marzia Rosati, Alexey Yu. Semenov, Carla Vale, Feng Wei, et al., and PHENIX Collaboration This article is available at Iowa State University Digital Repository: http://lib.dr.iastate.edu/physastro_pubs/261 Cross sections and double-helicity asymmetries of midrapidity inclusive charged hadrons in p þ p collisions at ffiffi s p 1⁄4 62:4 GeV A. Adare, S. Afanasiev, C. Aidala, N.N. Ajitanand, Y. Akiba, H. Al-Bataineh, J. Alexander, K. Aoki, L. Aphecetche, J. Asai, E. T. Atomssa, R. Averbeck, T. C. Awes, B. Azmoun, V. Babintsev, M. Bai, G. Baksay, L. Baksay, A. Baldisseri, K. N. Barish, P. D. Barnes,* B. Bassalleck, A. T. Basye, S. Bathe, S. Batsouli, V. Baublis, C. Baumann, A. Bazilevsky, S. Belikov,* R. Bennett, A. Berdnikov, Y. Berdnikov, A. A. Bickley, J. G. Boissevain, H. Borel, K. Boyle, M. L. Brooks, H. Buesching, V. Bumazhnov, G. Bunce, S. Butsyk, C.M. Camacho, S. Campbell, B. S. Chang, W.C. Chang, J.-L. Charvet, S. Chernichenko, C.Y. Chi, M. Chiu, I. J. Choi, R. K. Choudhury, T. Chujo, P. Chung, A. Churyn, V. Cianciolo, Z. Citron, B. A. Cole, P. Constantin, M. Csanád, T. Csörgő, T. Dahms, S. Dairaku, K. Das, A. Datta, G. David, A. Denisov, D. d’Enterria, A. Deshpande, E. J. Desmond, O. Dietzsch, A. Dion, M. Donadelli, O. Drapier, A. Drees, K.A. Drees, A.K. Dubey, A. Durum, D. Dutta, V. Dzhordzhadze, Y. V. Efremenko, F. Ellinghaus, T. Engelmore, A. Enokizono, H. En’yo, S. Esumi, K.O. Eyser, B. Fadem, D. E. Fields, M. Finger, M. Finger, Jr., 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, J. Gosset, Y. Goto, R. Granier de Cassagnac, N. Grau, S. V. Greene, M. Grosse Perdekamp, T. Gunji, H.-Å. Gustafsson,* A. Hadj Henni, J. S. Haggerty, H. Hamagaki, R. Han, E. P. Hartouni, K. Haruna, E. Haslum, R. Hayano, X. He, M. Heffner, T.K. Hemmick, T. Hester, J. C. Hill, M. Hohlmann, W. Holzmann, K. Homma, B. Hong, T. Horaguchi, D. Hornback, S. Huang, T. Ichihara, R. Ichimiya, H. Iinuma, Y. Ikeda, K. Imai, J. Imrek, 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, F. Kajihara, S. Kametani, N. Kamihara, J. Kamin, J. H. Kang, J. Kapustinsky, D. Kawall, A.V. Kazantsev, T. Kempel, A. Khanzadeev, K.M. Kijima, J. Kikuchi, B. I. Kim, D.H. Kim, D. J. Kim, E. Kim, S. H. Kim, E. Kinney, K. Kiriluk, Á. Kiss, E. Kistenev, J. Klay, C. Klein-Boesing, L. Kochenda, B. Komkov, M. Konno, J. Koster, A. Kozlov, A. Král, A. Kravitz, G. J. Kunde, K. Kurita, M. Kurosawa, M. J. Kweon, Y. Kwon, G. S. Kyle, R. Lacey, Y. S. Lai, J. G. Lajoie, D. Layton, A. Lebedev, D.M. Lee, K. B. Lee, T. Lee, M. J. Leitch, M.A. L. Leite, B. Lenzi, X. Li, P. Liebing, T. Liška, A. Litvinenko, H. Liu, M.X. Liu, B. Love, D. Lynch, C. F. Maguire, Y. I. Makdisi, A. Malakhov, M.D. Malik, V. I. Manko, E. Mannel, Y. Mao, L. Mašek, H. Masui, F. Matathias, M. McCumber, P. L. McGaughey, N. Means, B. Meredith, Y. Miake, P. Mikeš, K. Miki, A. Milov, M. Mishra, J. T. Mitchell, A. K. Mohanty, Y. Morino, A. Morreale, D. P. Morrison, T. V. Moukhanova, D. Mukhopadhyay, J. Murata, S. Nagamiya, J. L. Nagle, M. Naglis, M. I. Nagy, I. Nakagawa, Y. Nakamiya, T. Nakamura, K. Nakano, J. Newby, M. Nguyen, T. Niita, R. Nouicer, A. S. Nyanin, E. O’Brien, S. X. Oda, C.A. Ogilvie, M. Oka, K. Okada, Y. Onuki, A. Oskarsson, M. Ouchida, K. Ozawa, R. Pak, A. P. T. Palounek, V. Pantuev, V. Papavassiliou, J. Park, W. J. Park, S. F. Pate, H. Pei, J.-C. Peng, H. Pereira, V. Peresedov, D.Yu. Peressounko, C. Pinkenburg, M. L. Purschke, A.K. Purwar, H. Qu, J. Rak, A. Rakotozafindrabe, I. Ravinovich, K. F. Read, S. Rembeczki, K. Reygers, V. Riabov, Y. Riabov, D. Roach, G. Roche, S. D. Rolnick, M. Rosati, S. S. E. Rosendahl, P. Rosnet, P. Rukoyatkin, P. Ružička, V. L. Rykov, B. Sahlmueller, N. Saito, T. Sakaguchi, S. Sakai, K. Sakashita, V. Samsonov, T. Sato, S. Sawada, K. Sedgwick, J. Seele, R. Seidl, A.Yu. Semenov, V. 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, A. Soldatov, R. A. Soltz, W. E. Sondheim, S. P. Sorensen, I. V. Sourikova, F. Staley, P.W. Stankus, E. Stenlund, M. Stepanov, A. Ster, S. P. Stoll, T. Sugitate, C. Suire, A. Sukhanov, J. Sziklai, E.M. Takagui, A. Taketani, R. Tanabe, Y. Tanaka, S. Taneja, K. Tanida, M. J. Tannenbaum, A. Taranenko, P. Tarján, H. Themann, T. L. Thomas, M. Togawa, A. Toia, L. Tomášek, Y. Tomita, H. Torii, R. S. Towell, V-N. Tram, I. Tserruya, Y. Tsuchimoto, C. Vale, H. Valle, H.W. van Hecke, A. Veicht, J. Velkovska, R. Vértesi, A.A. Vinogradov, M. Virius, V. Vrba, E. Vznuzdaev, X. R. Wang, Y. Watanabe, F. Wei, J. Wessels, S. N. White, D. Winter, C. L. Woody, M. Wysocki, W. Xie, Y. L. Yamaguchi, K. Yamaura, R. Yang, A. Yanovich, J. Ying, S. Yokkaichi, G. R. Young, I. Younus, I. E. Yushmanov, W.A. Zajc, O. Zaudtke, C. Zhang, S. Zhou, and L. Zolin PHYSICAL REVIEW D 86, 092006 (2012) 1550-7998=2012=86(9)=092006(13) 092006-1 2012 American Physical Society (PHENIX Collaboration) Abilene Christian University, Abilene, Texas 79699, USA Institute of Physics, Academia Sinica, Taipei 11529, Taiwan Department of Physics, Banaras Hindu University, Varanasi 221005, India Bhabha Atomic Research Centre, Bombay 400 085, India Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA Physics Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA University of California-Riverside, Riverside, California 92521, USA Charles University, Ovocný trh 5, Praha 1, 116 36, Prague, Czech Republic Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413, People’s Republic of China Center for Nuclear Study, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan University of Colorado, Boulder, Colorado 80309, USA Columbia University, New York, New York 10027 and Nevis Laboratories, Irvington, New York 10533, USA Czech Technical University, Zikova 4, 166 36 Prague 6, Czech Republic Dapnia, CEA Saclay, F-91191, Gif-sur-Yvette, France Debrecen University, H-4010 Debrecen, Egyetem tér 1, Hungary ELTE, Eötvös Loránd University, H-1117 Budapest, Pázmány P. s. 1/A, Hungary Florida Institute of Technology, Melbourne, Florida 32901, USA Florida State University, Tallahassee, Florida 32306, USA Georgia State University, Atlanta, Georgia 30303, USA Hiroshima University, Kagamiyama, Higashi-Hiroshima 739-8526, Japan IHEP Protvino, State Research Center of Russian Federation, Institute for High Energy Physics, Protvino, 142281, Russia University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA Institute for Nuclear Research of the Russian Academy of Sciences, prospekt 60-letiya Oktyabrya 7a, Moscow 117312, Russia Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, 182 21 Prague 8, Czech Republic Iowa State University, Ames, Iowa 50011, USA Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region, Russia KEK, High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan Korea University, Seoul, 136-701, Korea Russian Research Center ‘‘Kurchatov Institute,’’ Moscow, 123098 Russia Kyoto University, Kyoto 606-8502, Japan Laboratoire Leprince-Ringuet, Ecole Polytechnique, CNRS-IN2P3, Route de Saclay, F-91128, Palaiseau, France Lawrence Livermore National Laboratory, Livermore, California 94550, USA Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA LPC, Université Blaise Pascal, CNRS-IN2P3, Clermont-Fd, 63177 Aubiere Cedex, France Department of Physics, Lund University, Box 118, SE-221 00 Lund, Sweden Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003-9337, USA Institut für Kernphysik, University of Muenster, D-48149 Muenster, Germany Muhlenberg College, Allentown, Pennsylvania 18104-5586, USA Myongji University, Yongin, Kyonggido 449-728, Korea Nagasaki Institute of Applied Science, Nagasaki-shi, Nagasaki 851-0193, Japan University of New Mexico, Albuquerque, New Mexico 87131, USA New Mexico State University, Las Cruces, New Mexico 88003, USA Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA IPN-Orsay, Universite Paris Sud, CNRS-IN2P3, BP1, F-91406, Orsay, France Peking University, Beijing 100871, People’s Republic of China PNPI, Petersburg Nuclear Physics Institute, Gatchina, Leningrad region, 188300, Russia RIKEN Nishina Center for Accelerator-Based Science, Wako, Saitama 351-0198, Japan RIKEN BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973-5000, USA Physics Department, Rikkyo University, 3-34-1 Nishi-Ikebukuro, Toshima, Tokyo 171-8501, Japan Saint Petersburg State Polytec

Measurements of the anisotropic flow coefficients v(2){Psi(2)}, v(3){Psi(3)}, v(4){Psi(4)}, and v(4){Psi(2)} for identified particles (pi(+/-), K-+/-, and p + (p) over bar) at midrapidity, obtained relative to the event planes Psi(m) at forward rapidities in Au + Au collisions at root s(NN) = 200 GeV, are presented as a function of collision centrality and particle transverse momenta p(T). The v(n) coefficients show characteristic patterns consistent with hydrodynamical expansion of the matter produced in the collisions. For each harmonic n, a modified valence quark-number N-q scaling [plotting v(n){Psi(m)}/(N-q)(n/2) versus transverse kinetic energies (KET)/N-q] is observed to yield a single curve for all the measured particle species for a broad range of KET. A simultaneous blast-wave model fit to the observed v(n){Psi(m)}(p(T)) coefficients and published particle spectra identifies radial flow anisotropies rho(n){Psi(m)} and spatial eccentricities s(n){Psi(m)} at freeze-out. These are generally smaller than the initial-state participant-plane geometric eccentricities epsilon(n){Psi(PP)(m)} as also observed in the final eccentricity from quantum interferometry measurements with respect to the event plane.

Experimental and theoretical studies of direct photon production in hadronic collisions essentially expand our insights in multiparticle production mechanisms. These photons are useful probes to investigate nuclear matter at all stages of the interaction. Soft photons play a particular role in these studies. Until now we have no explanation for the experimentally observed excess of soft photons. These photons have low transverse momenta \( p_{T} < 0.1\) GeV/c, \( \vert x\vert < 0.01\) . In this domain their yield exceeds the theoretical estimates by 5-8 times. The registration of soft photons at Nuclotron (LHEP, JINR) has been carried out by the electromagnetic calorimeter built by the SVD-2 Collaboration. Soft photon electromagnetic calorimeter was tested at U-70, IHEP (Protvino). For the first time the soft photon yield at interactions of 3.5A GeV/c per nucleon deuterium and lithium beams has been measured. The obtained energy spectra confirm the increased yield of soft photons with their energy less than 50MeV (in the laboratory system) in comparison with theoretical predictions and agree with previous experiments at high-energy interactions. It is planned to continue soft photon study at the future accelerator complex NICA with heavy-ion beams.