Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at √s= 200GeV

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x \u3e 0.05

Beam-Energy-Dependent Two-Pion Interferometry and the Freeze-Out Eccentricity of Pions Measured in Heavy Ion Collisions at the Star Detector

We present results of analyses of two-pion interferometry in Au + Au collisions at root s(NN) = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV measured in the STAR detector as part of the BNL Relativistic Heavy Ion Collider Beam Energy Scan program. The extracted correlation lengths (Hanbury-Brown-Twiss radii) are studied as a function of beam energy, azimuthal angle relative to the reaction plane, centrality, and transverse mass (m(T)) of the particles. The azimuthal analysis allows extraction of the eccentricity of the entire fireball at kinetic freeze-out. The energy dependence of this observable is expected to be sensitive to changes in the equation of state. A new global fit method is studied as an alternate method to directly measure the parameters in the azimuthal analysis. The eccentricity shows a monotonic decrease with beam energy that is qualitatively consistent with the trend from all model predictions and quantitatively consistent with a hadronic transport model

Effect of event selection on jetlike correlation measurement in d+Au collisions at sNN=200 GeV

AbstractDihadron correlations are analyzed in sNN=200 GeV d+Au collisions classified by forward charged particle multiplicity and zero-degree neutral energy in the Au-beam direction. It is found that the jetlike correlated yield increases with the event multiplicity. After taking into account this dependence, the non-jet contribution on the away side is minimal, leaving little room for a back-to-back ridge in these collisions

J/ψ polarization in p+p collisions at s=200 GeV in STAR

AbstractWe report on a polarization measurement of inclusive J/ψ mesons in the di-electron decay channel at mid-rapidity at 2<pT<6 GeV/c in p+p collisions at s=200 GeV. Data were taken with the STAR detector at RHIC. The J/ψ polarization measurement should help to distinguish between different models of the J/ψ production mechanism since they predict different pT dependences of the J/ψ polarization. In this analysis, J/ψ polarization is studied in the helicity frame. The polarization parameter λθ measured at RHIC becomes smaller towards high pT, indicating more longitudinal J/ψ polarization as pT increases. The result is compared with predictions of presently available models

Beam-energy Dependence Of Charge Balance Functions From Au + Au Collisions At Energies Available At The Bnl Relativistic Heavy Ion Collider

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Balance functions have been measured in terms of relative pseudorapidity (Δη) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at sNN=7.7GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at sNN=2.76TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at sNN=7.7 GeV implies that a QGP is still being created at this relatively low energy. © 2016 American Physical Society.942CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoMinistry of Education and Science of the Russian FederationMOE, Ministry of Education of the People's Republic of ChinaMOST, Ministry of Science and Technology of the People's Republic of ChinaNRF-2012004024, National Research FoundationNSF, National Stroke FoundationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Energy dependence of acceptance-corrected dielectron excess mass spectrum at mid-rapidity in Au + Au collisions at s NN = 19.6 and 200 GeV

The acceptance-corrected dielectron excess mass spectra, where the known hadronic sources have been subtracted from the inclusive dielectron mass spectra, are reported for the first time at mid-rapidity |yee|&lt;1 in minimum-bias Au+Au collisions at √sNN=19.6 and 200 GeV. The excess mass spectra are consistently described by a model calculation with a broadened ρ spectral function for Mee&lt;1.1 GeV/c2. The integrated dielectron excess yield at √sNN=19.6 GeV for 0.

J/ψ Production At Low Pt In Au+au And Cu+cu Collisions At Snn =200 Gev With The Star Detector

The J/ψ pT spectrum and nuclear modification factor (RAA) are reported for pT<5GeV/c and |y|<1 from 0% to 60% central Au+Au and Cu+Cu collisions at sNN=200GeV at STAR. A significant suppression of pT-integrated J/ψ production is observed in central Au+Au events. The Cu+Cu data are consistent with no suppression, although the precision is limited by the available statistics. RAA in Au+Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with pT. The data are compared to high-pT STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low pT are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration. © 2014 American Physical Society.902CNRS/IN2P3; NSF; Arthritis National Research Foundation; NRF-2012004024; ANRF; Arthritis National Research FoundationMatsui, T., Satz, H., (1986) Phys Lett. B, 178, p. 416. , PYLBAJ 0370-2693 10.1016/0370-2693(86)91404-8Digal, S., Petreczky, P., Satz, H., (2001) Phys. Rev. D, 64, p. 094015. , 0556-2821 10.1103/PhysRevD.64.094015Karsch, F., Kharzeev, D., Satz, H., Sequential charmonium dissociation (2006) Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 637 (1-2), pp. 75-80. , DOI 10.1016/j.physletb.2006.03.078, PII S037026930600445XBraun-Munzinger, P., Stachel, J., The quest for the quark-gluon plasma (2007) Nature, 448 (7151), pp. 302-309. , DOI 10.1038/nature06080, PII NATURE06080Abreu, M.C., (1999) Phys. Lett. B, 449, p. 128. , (NA38 Collaboration),. PYLBAJ 0370-2693 10.1016/S0370-2693(99)00057-XAbreu, M.C., (1997) Phys. Lett. B, 410, p. 327. , (NA50 Collaboration),. PYLBAJ 0370-2693 10.1016/S0370-2693(97)00914-3Arnaldi, R., Banicz, K., Castor, J., Chaurand, B., Cicalo, C., Colla, A., Cortese, P., Wohri, H.K., J/ψ production in indium-indium collisions at 158GeV/nucleon (2007) Physical Review Letters, 99 (13), p. 132302. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevLett.99.132302&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevLett.99.132302Adare, A., Afanasiev, S., Aidala, C., Ajitanand, N.N., Akiba, Y., Al-Bataineh, H., Alexander, J., Al-Jamel, A., J/ψ production versus centrality, transverse momentum, and rapidity in Au+Au collisions at s NN=200 GeV (2007) Physical Review Letters, 98 (23), p. 232301. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevLett.98.232301&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevLett.98.232301Adamczyk, L., (2013) Phys. Lett. B, 722, p. 55. , (STAR Collaboration),. PYLBAJ 0370-2693 10.1016/j.physletb.2013.04.010Abelev, B., (2012) Phys. Rev. Lett., 109, p. 072301. , (ALICE Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.109.072301Chatrchyan, S., (2012) J. High Energy Phys., (5), p. 063. , (CMS Collaboration),. JHEPFG 1029-8479 10.1007/JHEP05(2012)063Braun-Munzinger, P., Stachel, J., (2000) Phys. Lett. B, 490, p. 196. , PYLBAJ 0370-2693 10.1016/S0370-2693(00)00991-6Grandchamp, L., Rapp, R., (2002) Nucl. Phys. A, 709, p. 415. , NUPABL 0375-9474 10.1016/S0375-9474(02)01027-8Gavin, S., Vogt, R., (1996) Nucl. Phys. A, 610, p. 442. , NUPABL 0375-9474 10.1016/S0375-9474(96)00376-4Capella, A., (1997) Phys. Lett. B, 393, p. 431. , PYLBAJ 0370-2693 10.1016/S0370-2693(96)01650-4Karsch, F., Petronzio, P., (1988) Z. Phys. C, 37, p. 627. , ZPCFD2 0170-9739 10.1007/BF01549724Adare, A., (2012) Phys. Rev. D, 85, p. 092004. , (PHENIX Collaboration),. 10.1103/PhysRevD.85.092004Charm, beauty and charmonium production at HERA-B (2005) European Physical Journal C, 43 (1-4), pp. 179-186. , DOI 10.1140/epjc/s2005-02308-8Vogt, R., Shadowing and absorption effects on J/ψ production in da collisions (2005) Physical Review C - Nuclear Physics, 71 (5), pp. 1-11. , http://oai.aps.org/oai/?verb=ListRecords&metadataPrefix= oai_apsmeta_2&set=journal:PRC:71, DOI 10.1103/PhysRevC.71.054902, 054902Gavin, S., Gyulassy, M., (1988) Phys. Lett. B, 214, p. 241. , PYLBAJ 0370-2693 10.1016/0370-2693(88)91476-1Noble, J.V., (1981) Phys. Rev. Lett., 46, p. 412. , PRLTAO 0031-9007 10.1103/PhysRevLett.46.412Tram, V., Arleo, F., (2009) Eur. Phys. J. C, 61, p. 847. , EPCFFB 1434-6044 10.1140/epjc/s10052-009-0864-yAlde, D., Baer, H., Carey, T., Garvey, G., Klein, A., (1991) Phys. Rev. Lett., 66, p. 133. , PRLTAO 0031-9007 10.1103/PhysRevLett.66.133Leitch, M., (1992) Nucl. Phys. A, 544, p. 197. , (E772 and E789 Collaboration),. NUPABL 0375-9474 10.1016/0375-9474(92) 90574-4Leitch, M., (2000) Phys. Rev. Lett., 84, p. 3256. , (NuSea Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.84.3256Alessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Baglin, C., Baldit, A., Beole, S., Willis, N., Charmonium production and nuclear absorption in p-A interactions at 450 GeV (2004) European Physical Journal C, 33 (1), pp. 31-40. , DOI 10.1140/epjc/s2003-01539-yAlessandro, B., Alexa, C., Arnaldi, R., Atayan, M., Beole, S., Boldea, V., Bordalo, P., Wu, T., A new measurement of J/ψ suppression in Pb-Pb collisions at 158 GeV per nucleon (2005) European Physical Journal C, 39 (3), pp. 335-345. , DOI 10.1140/epjc/s2004-02107-9Arnaldi, R., (2012) Phys. Lett. B, 706, p. 263. , (NA60 Collaboration),. PYLBAJ 0370-2693 10.1016/j.physletb.2011.11.042Adare, A., (2013) Phys. Rev. C, 87, p. 034904. , (PHENIX Collaboration),. 10.1103/PhysRevC.87.034904Adare, A., (2013) Phys. Rev. Lett., 111, p. 202301. , (PHENIX Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.111.202301Adare, A., (2011) Phys. Rev. Lett., 107, p. 142301. , (PHENIX Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.107.142301Zhao, X., Rapp, R., (2010) Phys. Rev. C, 82, p. 064905. , PRVCAN 0556-2813 10.1103/PhysRevC.82.064905Adamczyk, L., (2013) Phys. Rev. Lett., 111, p. 052301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.111.052301Ackermann, K.H., Adams, N., Adler, C., Ahammed, Z., Ahmad, S., Allgower, C., Amonett, J., Harris, J.W., STAR detector overview (2003) Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 499 (2-3), pp. 624-632. , DOI 10.1016/S0168-9002(02)01960-5Llope, W.J., (2004) Nucl. Instrum. Methods Phys. Res., Sect. A, 522, p. 252. , NIMAER 0168-9002 10.1016/j.nima.2003.11.414Adler, C., Denisov, A., Garcia, E., Murray, M., Strobele, H., White, S., The RHIC zero-degree calorimeters (2003) Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 499 (2-3), pp. 433-436. , DOI 10.1016/j.nima.2003.08.112Llope, W., (2012) Nucl. Instrum. Methods Phys. Res., Sect. A, 661, pp. S110. , (Suppl. 1),. NIMAER 0168-9002 10.1016/j.nima.2010.07.086Reed, R., (2010) J. Phys.: Conf. Ser., 219, p. 03020. , 1742-6596 10.1088/1742-6596/219/3/032020Beringer, J., (2012) Phys. Rev. D, 86, p. 010001. , (Particle Data Group),. 10.1103/PhysRevD.86.010001Beddo, M., Bielick, E., Fornek, T., Guarino, V., Hill, D., Krueger, K., LeCompte, T., Suaide, A.A.P., The STAR barrel electromagnetic calorimeter (2003) Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 499 (2-3), pp. 725-739. , DOI 10.1016/S0168-9002(02)01970-8Miller, M.L., Reygers, K., Sanders, S.J., Steinberg, P., (2007) Annu. Rev. Nucl. Part. Sci., 57, p. 205. , ARPSDF 0163-8998 10.1146/annurev.nucl.57.090506.123020Abelev, B.I., (2009) Phys. Lett. B, 673, p. 183. , (STAR Collaboration),. PYLBAJ 0370-2693 10.1016/j.physletb.2009.02.037Bichsel, H., A method to improve tracking and particle identification in TPCs and silicon detectors (2006) Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 562 (1), pp. 154-197. , DOI 10.1016/j.nima.2006.03.009, PII S0168900206005353Shao, M., (2006) Nucl. Instrum. Methods Phys. Res., Sect. A, 558, p. 419. , NIMAER 0168-9002 10.1016/j.nima.2005.11.251Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.79.034909Adamczyk, L., (STAR Collaboration), arXiv:1402.1791Spiridonov, A., arXiv:hep-ex/0510076Abelev, B.I., (2009) Phys. Rev. C, 80, p. 041902. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.80.041902Tang, Z., Xu, Y., Ruan, L., Van Buren, G., Wang, F., Xu, Z., (2009) Phys. Rev. C, 79, p. 051901. , PRVCAN 0556-2813 10.1103/PhysRevC.79.051901Tang, Z., Yi, L., Ruan, L., Shao, M., Chen, H., (2013) Chin. Phys. Lett., 30, p. 031201. , CPLEEU 0256-307X 10.1088/0256-307X/30/3/031201Adare, A., (2010) Phys. Rev. D, 82, p. 012001. , (PHENIX Collaboration),. 10.1103/PhysRevD.82.012001Liu, Y., Qu, Z., Xu, N., Zhuang, P., (2009) Phys. Lett. B, 678, p. 72. , PYLBAJ 0370-2693 10.1016/j.physletb.2009.06.006Heinz, U.W., Shen, C., (private communication)Adare, A., (2008) Phys. Rev. Lett., 101, p. 122301. , (PHENIX Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.101.122301Adams, J., (2003) Phys. Rev. Lett, 91, p. 172302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.91.172302Adare, A., Afanasiev, S., Aidala, C., Ajitanand, N.N., Akiba, Y., Al-Bataineh, H., Alexander, J., Aoki, K., J/ψ Production versus transverse momentum and rapidity in p+p collisions at s=200GeV (2007) Physical Review Letters, 98 (23), p. 232002. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevLett.98.232002&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevLett.98.232002Zhao, X., Rapp, R., (2008) Phys. Lett. B, 664, p. 253. , PYLBAJ 0370-2693 10.1016/j.physletb.2008.03.06

Dielectron Azimuthal Anisotropy At Mid-rapidity In Au+au Collisions At Snn =200 Gev

We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e- pairs) at mid-rapidity from sNN=200 GeV Au+Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (pT) for different invariant-mass regions. In the mass region Mee<1.1 GeV/c2 the dielectron v2 measurements are found to be consistent with expectations from π0,η,ω, and φ decay contributions. In the mass region 1.1<Mee<2.9GeV/c2, the measured dielectron v2 is consistent, within experimental uncertainties, with that from the cc¯ contributions.906Adams, J., (2005) Nucl. Phys. A, 757, p. 102. , NUPABL 0375-9474Arsene, I., (2005) Nucl. Phys. A, 757, p. 1. , NUPABL 0375-9474Adcox, K., (2005) Nucl. Phys. A, 757, p. 184. , NUPABL 0375-9474Back, B.B., (2005) Nucl. Phys. A, 757, p. 28. , NUPABL 0375-9474Rapp, R., Wambach, J., (2002) Adv. Nucl. Phys., 25, p. 1. , 0065-2970David, G., Rapp, R., Xu, Z., (2008) Phys. Rep., 462, p. 176. , PRPLCM 0370-1573Agakichiev, G., (2005) Eur. Phys. J. C, 41, p. 475. , EPCFFB 1434-6044Arnaldi, R., (2006) Phys. Rev. Lett., 96, p. 162302. , PRLTAO 0031-9007Brown, G.E., Rho, M., (1996) Phys. Rep., 269, p. 333. , PRPLCM 0370-1573Rapp, R., Wambach, J., (1999) Eur. Phys. J. A, 6, p. 415. , EPJAFV 1434-6001Dusling, K., Teaney, D., Zahed, I., (2007) Phys. Rev. C, 75, p. 024908. , PRVCAN 0556-2813Van Hees, H., Rapp, R., (2008) Nucl. Phys. A, 806, p. 339. , NUPABL 0375-9474Renk, T., Ruppert, J., (2008) Phys. Rev. C, 77, p. 024907. , PRVCAN 0556-2813Adare, A., (2010) Phys. Rev. C, 81, p. 034911. , PRVCAN 0556-2813Adamczyk, L., (2014) Phys. Rev. Lett., 113, p. 022301. , a longer version (unpublished). PRLTAO 0031-9007Rapp, R., Wambach, J., Van Hees, H., (2010) Relativistic Heavy-Ion Physics, , in, edited by R. Stock, Landolt Börnstein New Series I/23A (Springer, Berlin), Chap. 4-1Linnyk, O., Cassing, W., Manninen, J., Bratkovskaya, E.L., Ko, C.M., (2012) Phys. Rev. C, 85, p. 024910. , PRVCAN 0556-2813Xu, J.-H., Chen, H.F., Dong, X., Wang, Q., Zhang, Y.F., (2012) Phys. Rev. C, 85, p. 024906. , PRVCAN 0556-2813Adare, A., (2010) Phys. Rev. Lett., 104, p. 132301. , PRLTAO 0031-9007Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813Adare, A., (2012) Phys. Rev. Lett., 109, p. 122302. , PRLTAO 0031-9007Van Hees, H., Gale, C., Rapp, R., (2011) Phys. Rev. C, 84, p. 054906. , PRVCAN 0556-2813Chatterjee, R., Srivastava, D.K., Heinz, U., Gale, C., (2007) Phys. Rev. C, 75, p. 054909. , PRVCAN 0556-2813Adare, A., (2009) Phys. Lett. B, 670, p. 313. , PYLBAJ 0370-2693Bonner, B., (2003) Nucl. Instrum. Methods A, 508, p. 181. , NIMAER 0168-9002Shao, M., (2002) Nucl. Instrum. Methods A, 492, p. 344Wu, J., (2005) Nucl. Instrum. Methods A, 538, p. 243. , NIMAER 0168-9002Landgraf, J.M., (2003) Nucl. Instrum. Methods A, 499, p. 762. , NIMAER 0168-9002Ackermann, K.H., (2003) Nucl. Instrum. Methods A, 499, p. 624. , NIMAER 0168-9002Anderson, M., (2003) Nucl. Instrum. Methods A, 499, p. 659. , NIMAER 0168-9002Bichsel, H., (2006) Nucl. Instrum. Methods A, 562, p. 154. , NIMAER 0168-9002Xu, Y., (2010) Nucl. Instrum. Methods A, 614, p. 28. , NIMAER 0168-9002Shao, M., (2006) Nucl. Instrum. Methods A, 558, p. 419. , NIMAER 0168-9002Adams, J., (2005) Phys. Lett. B, 616, p. 8. , PYLBAJ 0370-2693Ruan, L., Ph.D. thesis, University of Science and Technology of China, 2005, arXiv:nucl-ex/0503018 (unpublished)Llope, W.J., (2004) Nucl. Instrum. Methods A, 522, p. 252. , NIMAER 0168-9002Adler, C., (2002) Phys. Rev. Lett., 89, p. 202301. , PRLTAO 0031-9007Adams, J., (2005) Phys. Rev. Lett., 94, p. 062301. , PRLTAO 0031-9007Adamczyk, L., (2012) Phys. Rev. C, 86, p. 024906. , PRVCAN 0556-2813Zhao, J., (2013), https://drupal.star.bnl.gov/STAR/theses/phd-32, Ph.D. thesis, Shanghai Institute of Applied Physics, (unpublished)Voloshin, S.A., Poskanzer, A.M., Snellings, R., (2010) Relativistic Heavy Ion Physics, pp. 5-54. , in, Landolt-Börnstein Vol. 1/23 (Springer-Verlag, Berlin), ppAdamczyk, L., (2013) Phys. Rev. C, 88, p. 014902. , PRVCAN 0556-2813Abelev, B.I., (2008) Phys. Rev. C, 77, p. 054901. , PRVCAN 0556-2813Abelev, B.I., (2006) Phys. Rev. Lett., 97, p. 152301. , PRLTAO 0031-9007Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , PRVCAN 0556-2813Abelev, B.I., (2009) Phys. Rev. C, 79, p. 064903. , PRVCAN 0556-2813Adams, J., (2005) Phys. Lett. B, 612, p. 181. , PYLBAJ 0370-2693Adler, S.S., (2007) Phys. Rev. C, 75, p. 024909. , PRVCAN 0556-2813Tang, Z., Xu, Y., Ruan, L., Van Buren, G., Wang, F., Xu, Z., (2009) Phys. Rev. C, 79, p. 051901. , (R) () PRVCAN 0556-2813Shao, M., Yi, L., Tang, Z., Chen, H., Li, C., Xu, Z., (2010) J. Phys. G, 37, p. 085104. , JPGPED 0954-3899Afanasiev, S., (2009) Phys. Rev. C, 80, p. 054907. , PRVCAN 0556-2813Adams, J., (2005) Phys. Rev. C, 72, p. 014904. , PRVCAN 0556-2813Abelev, B.I., (2007) Phys. Rev. Lett., 99, p. 112301. , PRLTAO 0031-9007Kroll, N.M., Wada, W., (1955) Phys. Rev., 98, p. 1355. , PHRVAO 0031-899XRuan, L., (2011) Nucl. Phys. A, 855, p. 269. , NUPABL 0375-9474Huang, B., (2011), Ph.D. thesis, University of Science and Technology of China, (unpublished)Sjöstrand, T., (2001) Comput. Phys. Commun., 135, p. 238. , CPHCBZ 0010-4655Adamczyk, L., (2012) Phys. Rev. D, 86, p. 072013. , PRVDAQ 1550-7998Agakishiev, H., (2011) Phys. Rev. D, 83, p. 052006. , PRVDAQ 1550-7998Adare, A., (2011) Phys. Rev. C, 84, p. 044905. , PRVCAN 0556-2813Adare, A., (2012) Phys. Rev. C, 85, p. 064914. , PRVCAN 0556-2813Adare, A., (2007) Phys. Rev. Lett., 98, p. 162301. , PRLTAO 0031-9007Adams, J., (2004) Phys. Rev. Lett., 92, p. 052302. , PRLTAO 0031-9007Vujanovic, G., Young, C., Schenke, B., Jeon, S., Rapp, R., Gale, C., (2013) Nucl. Phys. A, 904-905, p. 557c. , NUPABL 0375-9474Vujanovic, G., Young, C., Schenke, B., Jeon, S., Rapp, R., Gale, C., (2014) Phys. Rev. C, 89, p. 034904. , PRVCAN 0556-281

Beam-energy Dependence Of Charge Separation Along The Magnetic Field In Au+au Collisions At Rhic

Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies. © 2014 American Physical Society.1135DOE; National Research Foundation; CNRS/IN2P3; NSF; National Research Foundation; NRF-2012004024; National Research FoundationVafa, C., Witten, E., (1984) Phys. Rev. Lett., 53, p. 535. , PRLTAO 0031-9007 10.1103/PhysRevLett.53.535Lee, D.T., (1973) Phys. Rev. D, 8, p. 1226. , PRVDAQ 0556-2821 10.1103/PhysRevD.8.1226Lee, T.D., Wick, G.C., (1974) Phys. Rev. D, 9, p. 2291. , PRVDAQ 0556-2821 10.1103/PhysRevD.9.2291Kharzeev, D.E., McLerran, L.D., Warringa, H.J., (2008) Nucl. Phys., A803, p. 227. , NUPBBO 0375-9474 10.1016/j.nuclphysa.2008.02.298Kharzeev, D., (2006) Phys. Lett. B, 633, p. 260. , PYLBAJ 0370-2693 10.1016/j.physletb.2005.11.075Kharzeev, D., Zhitnitsky, A., (2007) Nucl. Phys., A797, p. 67. , NUPBBO 0375-9474 10.1016/j.nuclphysa.2007.10.001Fukushima, K., Kharzeev, D.E., Warringa, H.J., (2008) Phys. Rev. D, 78, p. 074033. , PRVDAQ 1550-7998 10.1103/PhysRevD.78.074033Kharzeev, E.D., (2010) Ann. Phys. (Amsterdam), 325, p. 205. , APNYA6 0003-4916 10.1016/j.aop.2009.11.002Gatto, R., Ruggieri, M., (2012) Phys. Rev. D, 85, p. 054013. , PRVDAQ 1550-7998 10.1103/PhysRevD.85.054013Abelev, B.I., (2009) Phys. Rev. Lett., 103, p. 251601. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.103.251601Abelev, B.I., (2010) Phys. Rev. C, 81, p. 054908. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.81.054908Adamczyk, L., (2013) Phys. Rev. C, 88, p. 064911. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.88.064911Adamczyk, L., (2014) Phys. Rev. C, 89, p. 044908. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.89.044908Ajitanand, N.N., Esumi, S., Lacey, R.A., Proceedings of the RBRC Workshops, 2010, 96. , http://www.bnl.gov/isd/documents/74466.pdf, (PHENIX Collaboration), in, Vol.Ajitanand, N.N., Lacey, R.A., Taranenko, A., Alexander, J.M., (2011) Phys. Rev. C, 83, p. 011901. , PRVCAN 0556-2813 10.1103/PhysRevC.83.011901Abelev, B.I., (2013) Phys. Rev. Lett., 110, p. 012301. , (ALICE Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.110.012301Bzdak, A., Koch, V., Liao, J., (2010) Phys. Rev. C, 81, p. 031901. , PRVCAN 0556-2813 10.1103/PhysRevC.81.031901Liao, J., Koch, V., Bzdak, A., (2010) Phys. Rev. C, 82, p. 054902. , PRVCAN 0556-2813 10.1103/PhysRevC.82.054902Kharzeev, D.E., Son, D.T., (2011) Phys. Rev. Lett., 106, p. 062301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.062301Voloshin, A.S., (2004) Phys. Rev. C, 70, p. 057901. , PRVCAN 0556-2813 10.1103/PhysRevC.70.057901Anderson, M., (2003) Nucl. Instrum. Methods Phys. Res., Sect. A, 499, p. 659. , NIMAER 0168-9002 10.1016/S0168-9002(02)01964-2Adams, J., (2005) Phys. Rev. C, 72, p. 014904. , (STAR Collaboration), ()PRVCAN 0556-2813 10.1103/PhysRevC.72.014904Agakishiev, G., (2012) Phys. Rev. C, 86, p. 014904. , (STAR Collaboration), ()PRVCAN 0556-2813 10.1103/PhysRevC.86.014904Adamczyk, L., (2012) Phys. Rev. C, 86, p. 054908. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.86.054908Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813 10.1103/PhysRevC.58.1671Barrette, J., (1997) Phys. Rev. C, 56, p. 3254. , PRVCAN 0556-2813 10.1103/PhysRevC.56.3254Ollitrault, J.-Y., Poskanzer, A.M., Voloshin, S.A., (2009) Phys. Rev. C, 80, p. 014904. , PRVCAN 0556-2813 10.1103/PhysRevC.80.014904Abelev, B.I., (2008) Phys. Rev. Lett., 101, p. 252301. , (STAR Collaboration), () and references therein. PRLTAO 0031-9007 10.1103/PhysRevLett.101.252301Bzdak, A., Koch, V., Liao, J., (2011) Phys. Rev. C, 83, p. 014905. , PRVCAN 0556-2813 10.1103/PhysRevC.83.014905Ray, R.L., Longacre, R.S., arXiv:nucl-ex/0008009;Ray, R.L., Longacre, R.S., (private communication)Bass, S.A., (1998) Prog. Part. Nucl. Phys., 41, p. 255. , PPNPDB 0146-6410 10.1016/S0146-6410(98)00058-1Bleicher, M., (1999) J. Phys. G, 25, p. 1859. , JPGPED 0954-3899 10.1088/0954-3899/25/9/308Ma, G.-L., Zhang, B., (2011) Phys. Lett. B, 700, p. 39. , PYLBAJ 0370-2693 10.1016/j.physletb.2011.04.057Okorokov, A.V., (2013) Int. J. Mod. Phys. e, 22, p. 1350041. , IMPEER 0218-3013 10.1142/S0218301313500419Bzdak, A., Koch, V., Liao, J., (2013) Lect. Notes Phys., 871, p. 503. , LNPHA4 0075-8450 10.1007/978-3-642-37305-

Measurement Of Charge Multiplicity Asymmetry Correlations In High-energy Nucleus-nucleus Collisions At Snn =200 Gev

A study is reported of the same- and opposite-sign charge-dependent azimuthal correlations with respect to the event plane in Au+Au collisions at sNN=200 GeV. The charge multiplicity asymmetries between the up/down and left/right hemispheres relative to the event plane are utilized. The contributions from statistical fluctuations and detector effects were subtracted from the (co-)variance of the observed charge multiplicity asymmetries. In the mid- to most-central collisions, the same- (opposite-) sign pairs are preferentially emitted in back-to-back (aligned on the same-side) directions. The charge separation across the event plane, measured by the difference, Δ, between the like- and unlike-sign up/down-left/right correlations, is largest near the event plane. The difference is found to be proportional to the event-by-event final-state particle ellipticity (via the observed second-order harmonic v2obs), where Δ=[1.3±1.4(stat)-1.0+4.0(syst)]×10- 5+[3.2±0.2(stat)-0.3+0.4(syst)]×10-3v2obs for 20-40% Au+Au collisions. The implications for the proposed chiral magnetic effect are discussed. © 2014 American Physical Society.894NRF-2012004024; National Research FoundationArsene, I., (2005) Nucl. Phys. A, 757, p. 1. , (BRAHMS Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.02.130Back, B.B., (2005) Nucl. Phys. A, 757, p. 28. , (PHOBOS Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.084Adams, J., (2005) Nucl. Phys. A, 757, p. 102. , (STAR Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.085Adcox, K., (2005) Nucl. Phys. A, 757, p. 184. , (PHENIX Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.086Lee, T.D., (1973) Phys. Rev. D, 8, p. 1226. , 0556-2821 10.1103/PhysRevD.8.1226Lee, T.D., Wick, G.C., (1974) Phys. Rev. D, 9, p. 2291. , 0556-2821 10.1103/PhysRevD.9.2291Morley, P.D., Schmidt, I.A., (1985) Z. Phys. C, 26, p. 627. , ZPCFD2 0170-9739 10.1007/BF01551807Kharzeev, D., Pisarski, R.D., Tytgat, M.H.G., (1998) Phys. Rev. Lett., 81, p. 512. , PRLTAO 0031-9007 10.1103/PhysRevLett.81.512Kharzeev, D., (2006) Phys. Lett. B, 633, p. 260. , PYLBAJ 0370-2693 10.1016/j.physletb.2005.11.075Kharzeev, D., Zhitnitsky, A., (2007) Nucl. Phys. A, 797, p. 67. , NUPABL 0375-9474 10.1016/j.nuclphysa.2007.10.001Fukushima, K., Kharzeev, D.E., Warringa, H.J., (2008) Phys. Rev. D, 78, p. 074033. , PRVDAQ 1550-7998 10.1103/PhysRevD.78.074033Kharzeev, D.E., McLerran, L.D., Warringa, H.J., (2008) Nucl. Phys. A, 803, p. 227. , NUPABL 0375-9474 10.1016/j.nuclphysa.2008.02.298Voloshin, S.A., (2004) Phys. Rev. C, 70, p. 057901. , PRVCAN 0556-2813 10.1103/PhysRevC.70.057901Abelev, B.I., (2009) Phys. Rev. Lett., 103, p. 251601. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.103.251601Abelev, B.I., (2010) Phys. Rev. C, 81, p. 054908. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.81.054908Abelev, B., (2013) Phys. Rev. Lett., 110, p. 012301. , (ALICE Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.110.012301Wang, Q., (2012), http://drupal.star.bnl.gov/STAR/theses/phd/quanwang, Ph.D. thesis, Purdue University, arXiv:1205.4638Ackermann, K.H., (2003) Nucl. Instrum. Methods A, 499, p. 624. , (STAR Collaboration),. NIMAER 0168-9002 10.1016/S0168-9002(02)01960-5Bieser, F.S., (2003) Nucl. Instrum. Methods A, 499, p. 766. , (STAR Collaboration),. NIMAER 0168-9002 10.1016/S0168-9002(02)01974-5Adler, C., (2003) Nucl. Instrum. Methods A, 499, p. 433. , NIMAER 0168-9002 10.1016/j.nima.2003.08.112Adams, J., (2004) Phys. Rev. Lett., 92, p. 112301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.92.112301Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.79.034909Ackermann, K.H., (1999) Nucl. Phys. A, 661, p. 681. , (STAR Collaboration),. NUPABL 0375-9474 10.1016/S0375-9474(99)85117-3Anderson, M., (2003) Nucl. Instrum. Methods A, 499, p. 659. , NIMAER 0168-9002 10.1016/S0168-9002(02)01964-2Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813 10.1103/PhysRevC.58.1671Wang, G., (2005), http://drupal.star.bnl.gov/STAR/theses/ph-d/gang-wang, Ph.D. thesis, UCLAAdamczyk, L., (2012) Phys. Rev. Lett., 108, p. 202301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.108.202301Wang, F., (2010) Phys. Rev. C, 81, p. 064902. , PRVCAN 0556-2813 10.1103/PhysRevC.81.064902Pratt, S., Schlichting, S., Gavin, S., (2011) Phys. Rev. C, 84, p. 024909. , PRVCAN 0556-2813 10.1103/PhysRevC.84.024909Adams, J., (2005) Phys. Rev. Lett., 95, p. 152301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.95.152301Aggarwal, M.M., (2010) Phys. Rev. C, 82, p. 024912. , (STAR collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.82.024912Abelev, B.I., (2009) Phys. Rev. Lett., 102, p. 052302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.102.052302Abelev, B.I., (2009) Phys. Rev. C, 80, p. 064912. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.80.064912Abelev, B.I., (2010) Phys. Rev. Lett., 105, p. 022301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.105.022301Agakishiev, H., (STAR Collaboration), arXiv:1010.0690Petersen, H., Renk, T., Bass, S.A., (2011) Phys. Rev. C, 83, p. 014916. , PRVCAN 0556-2813 10.1103/PhysRevC.83.014916Adamczyk, L., (2013) Phys. Rev. C, 88, p. 064911. , (STAR Collaboration),. 10.1103/PhysRevC.88.064911Asakawa, M., Majumder, A., Müller, B., (2010) Phys. Rev. C, 81, p. 064912. , PRVCAN 0556-2813 10.1103/PhysRevC.81.064912Bzdak, A., Koch, V., Liao, J., (2010) Phys. Rev. C, 81, pp. 031901R. , PRVCAN 0556-2813 10.1103/PhysRevC.81.031901Liao, J., Koch, V., Bzdak, A., (2010) Phys. Rev. C, 82, p. 054902. , PRVCAN 0556-2813 10.1103/PhysRevC.82.054902Ma, G.-L., Zhang, B., (2011) Phys. Lett. B, 700, p. 39. , PYLBAJ 0370-2693 10.1016/j.physletb.2011.04.057Voloshin, S.A., (2010) Phys. Rev. Lett., 105, p. 172301. , PRLTAO 0031-9007 10.1103/PhysRevLett.105.17230