Measurement of the Bottom contribution to non-photonic electron production in p+pp+p collisions at s\sqrt{s} =200 GeV

The contribution of $B$ meson decays to non-photonic electrons, which are mainly produced by the semi-leptonic decays of heavy flavor mesons, in $p+p$ collisions at $\sqrt{s} =$ 200 GeV has been measured using azimuthal correlations between non-photonic electrons and hadrons. The extracted $B$ decay contribution is approximately 50% at a transverse momentum of $p_{T} \geq 5$ GeV/$c$. These measurements constrain the nuclear modification factor for electrons from $B$ and $D$ meson decays. The result indicates that $B$ meson production in heavy ion collisions is also suppressed at high $p_{T}$.Comment: 6 pages, 4 figures, accepted by PR

Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV

We report a measurement of the longitudinal double-spin asymmetry A_LL and the differential cross section for inclusive Pi0 production at midrapidity in polarized proton collisions at sqrt(s) = 200 GeV. The cross section was measured over a transverse momentum range of 1 < p_T < 17 GeV/c and found to be in good agreement with a next-to-leading order perturbative QCD calculation. The longitudinal double-spin asymmetry was measured in the range of 3.7 < p_T < 11 GeV/c and excludes a maximal positive gluon polarization in the proton. The mean transverse momentum fraction of Pi0's in their parent jets was found to be around 0.7 for electromagnetically triggered events.Comment: 6 pages, 3 figures, submitted to Phys. Rev. D (RC

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

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

Fluctuations Of Charge Separation Perpendicular To The Event Plane And Local Parity Violation In S Nn = 200 Gev Au + Au Collisions At The Bnl Relativistic Heavy Ion Collider

Previous experimental results based on data (∼15×106 events) collected by the STAR detector at the BNL Relativistic Heavy Ion Collider suggest event-by-event charge-separation fluctuations perpendicular to the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57×106 events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion. © 2013 American Physical Society.886NRF-2012004024; National Research FoundationLee, T.D., Yang, C.N., (1956) Phys. Rev., 104. , 1, 254. 0031-899X PHRVAO 10.1103/PhysRev.104.254Vafa, C., Witten, E., (1984) Phys. Rev. Lett., 53. , 2, 535. 0031-9007 PRLTAO 10.1103/PhysRevLett.53.535Lee, T.D., (1973) Phys. Rev. D, 8. , 3, 1226. 0556-2821 10.1103/PhysRevD.8.1226Lee, T.D., Wick, G.C., (1974) Phys. Rev. D, 9. , 4, 2291. 0556-2821 10.1103/PhysRevD.9.2291Kharzeev, D., Parity violation in hot QCD: Why it can happen, and how to look for it (2006) Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 633 (2-3), pp. 260-264. , DOI 10.1016/j.physletb.2005.11.075, PII S0370269305017430Kharzeev, D., Zhitnitsky, A., (2007) Nucl. Phys. A, 797. , 6, 67. 0375-9474 NUPABL 10.1016/j.nuclphysa.2007.10.001Kharzeev, D., McLerran, L.D., Warringa, H.J., (2008) Nucl. Phys. A, 803. , 7, 227. 0375-9474 NUPABL 10.1016/j.nuclphysa.2008.02.298Fukushima, K., Kharzeev, D.E., Warringa, H.J., (2008) Phys. Rev. D, 78. , 8, 074033. 1550-7998 PRVDAQ 10.1103/PhysRevD.78.074033Abelev, B.I., (2009) Phys. Rev. Lett., 103. , 9 (STAR Collaboration), 251601. 0031-9007 PRLTAO 10.1103/PhysRevLett.103. 251601Abelev, B.I., (2010) Phys. Rev. C, 81. , 10 (STAR Collaboration), 054908. 0556-2813 PRVCAN 10.1103/PhysRevC.81. 054908Abelev, B.I., (2013) Phys. Rev. Lett., 110. , 11 (ALICE Collaboration), 012301. 0031-9007 PRLTAO 10.1103/PhysRevLett. 110.012301Ackermann, 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)01960-5Adams, J., Aggarwal, M.M., Ahammed, Z., Amonett, J., Anderson, B.D., Arkhipkin, D., Averichev, G.S., Bai, Y., Directed flow in Au+Au collisions at sNN=62.4 GeV (2006) Physical Review C - Nuclear Physics, 73 (3), pp. 1-7. , http://oai.aps.org/oai?verb=GetRecord&Identifier=oai:aps.org: PhysRevC.73.034903&metadataPrefix=oai_apsmeta_2, DOI 10.1103/PhysRevC.73.034903, 034903Adamczyk, L., (2012) Phys. Rev. Lett., 108. , 14 (STAR Collaboration), 202301. 0031-9007 PRLTAO 10.1103/PhysRevLett. 108.202301Voloshin, S.A., Parity violation in hot QCD: How to detect it (2004) Physical Review C - Nuclear Physics, 70 (5), pp. 0579011-0579012. , DOI 10.1103/PhysRevC.70.057901, 057901Poskanzer, A.M., Voloshin, S.A., Methods for analyzing anisotropic flow in relativistic nuclear collisions (1998) Physical Review C - Nuclear Physics, 58 (3), pp. 1671-1678. , DOI 10.1103/PhysRevC.58.1671Ollitrault, J.-Y., Poskanzer, A.M., Voloshin, S.A., (2009) Phys. Rev. C, 80. , 17, 014904. 0556-2813 PRVCAN 10.1103/PhysRevC.80.014904Pratt, S., Schlichting, S., Gavin, S., (2011) Phys. Rev. C, 84. , 18, 024909. 0556-2813 PRVCAN 10.1103/PhysRevC.84.024909Schlichting, S., Pratt, S., (2011) Phys. Rev. C, 83. , 19, 014913. 0556-2813 PRVCAN 10.1103/PhysRevC.83.014913Selyuzhenkov, I., Voloshin, S., (2008) Phys. Rev. C, 77. , 20, 034904. 0556-2813 PRVCAN 10.1103/PhysRevC.77.034904Kisiel, A., (2006) Comput. Phys. Commun., 174. , 21, 669. 0010-4655 CPHCBZ 10.1016/j.cpc.2005.11.010Bzdak, A., Koch, V., Liao, J., (2011) Phys. Rev. C, 83. , 22, 014905. 0556-2813 PRVCAN 10.1103/PhysRevC.83.014905Adams, J., Aggarwal, M.M., Ahammed, Z., Amonett, J., Anderson, B.D., Arkhipkin, D., Averichev, G.S., Grebenyuk, O., Azimuthal anisotropy in Au+Au collisions at sNN=200GeV (2005) Physical Review C - Nuclear Physics, 72 (1), pp. 1-23. , http://oai.aps.org/oai/?verb=ListRecords&metadataPrefix= oai_apsmeta_2&set=journal:PRC:72, DOI 10.1103/PhysRevC.72.014904, 014904Ray, R.L., Longacre, R.S., 24, arXiv:nucl-ex/0008009 and private communicationKopylov, G.I., Podgoretsky, M.I., Kopylov, G.I., Podgoretsky, M.I., (1972) Sov. J. Nucl. Phys., 15. , 25a, 219 ()25b, Phys. Lett. B. 50, 472 (1974) 0370-2693 PYLBAJ 10.1016/0370-2693(74)90263-925c, Sov. J. Part. Nucl. 20, 266 (1989)Goldhaber, G., Goldhaber, S., Lee, W., Pais, A., (1960) Phys. Rev., 120. , 26, 325. 0031-899X PHRVAO 10.1103/PhysRev.120.32

Event-plane-dependent Dihadron Correlations With Harmonic Vn Subtraction In Au + Au Collisions At S Nn =200 Gev

STAR measurements of dihadron azimuthal correlations (Δφ) are reported in midcentral (20-60%) Au+Au collisions at sNN=200 GeV as a function of the trigger particle's azimuthal angle relative to the event plane, φs=|φt-ψEP|. The elliptic (v2), triangular (v3), and quadratic (v4) flow harmonic backgrounds are subtracted using the zero yield at minimum (ZYAM) method. The results are compared to minimum-bias d+Au collisions. It is found that a finite near-side (|Δφ|π/2) correlation shows a modification from d+Au data, varying with φs. The modification may be a consequence of path-length-dependent jet quenching and may lead to a better understanding of high-density QCD. © 2014 American Physical Society.894DOE; U.S. Department of EnergyArsene, I., (2005) Nucl. Phys. A, 757, p. 1. , (BRAHMS Collaboration), () NUPABL 0375-9474 10.1016/j.nuclphysa.2005.02. 130;Back, B.B., (2005) Nucl. Phys. A, 757, p. 28. , (PHOBOS Collaboration), () NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03. 084;Adams, J., (2005) Nucl. Phys. A, 757, p. 102. , (STAR Collaboration), () NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03. 085;Adcox, K., (2005) Nucl. Phys. A, 757, p. 184. , (PHENIX Collaboration),. NUPABL 0375-9474 10.1016/j.nuclphysa.2005.03.086Heinz, U., Kolb, P.F., (2002) Nucl. Phys. A, 702, p. 269. , NUPABL 0375-9474 10.1016/S0375-9474(02)00714-5Wang, X.-N., Gyulassy, M., (1992) Phys. Rev. Lett., 68, p. 1480. , PRLTAO 0031-9007 10.1103/PhysRevLett.68.1480Adler, S., (2003) Phys. Rev. Lett., 91, p. 072301. , (PHENIX Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.91. 072301;Adams, J., (2003) Phys. Rev. Lett., 91, p. 072304. , (STAR Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.91.072304;Adler, C., (2003) Phys. Rev. Lett., 90, p. 082302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.90.082302Adams, J., (2005) Phys. Rev. Lett., 95, p. 152301. , (STAR Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.95.152301;Aggarwal, M.M., (2010) Phys. Rev. C, 82, p. 024912. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.82.024912Adams, J., (2004) Phys. Rev. Lett., 93, p. 252301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.93.252301Poskanzer, A.M., Voloshin, S.A., (1998) Phys. Rev. C, 58, p. 1671. , PRVCAN 0556-2813 10.1103/PhysRevC.58.1671Alver, B., (2008) Phys. Rev. C, 77, p. 014906. , PRVCAN 0556-2813 10.1103/PhysRevC.77.014906Feng, A., (2008), Ph.D. thesis, Institute of Particle Physics, CCNU, (unpublished);Konzer, J., (2013), Ph.D. thesis, Purdue University, (unpublished)Agakishiev, H., (STAR Collaboration), arXiv:1010.0690Ackermann, K.H., (2003) Nucl. Instrum. Meth., A499, p. 624. , (STAR Collaboration),. NIMAER 0168-9002 10.1016/S0168-9002(02)01960-5Ackermann, K.H., (1999) Nucl. Phys. A, 661, p. 681. , (STAR Collaboration),. NUPABL 0375-9474 10.1016/S0375-9474(99)85117-3Adams, J., (2004) Phys. Rev. Lett., 92, p. 112301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.92.112301Borghini, N., Dinh, P.M., Ollitrault, J.Y., (2000) Phys. Rev. C, 62, p. 034902. , PRVCAN 0556-2813 10.1103/PhysRevC.62.034902Adams, J., (2005) Phys. Rev. C, 72, p. 014904. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.72.014904Abelev, B.I., (2009) Phys. Rev. C, 79, p. 034909. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.79.034909Bielcikova, J., (2004) Phys. Rev C, 69, p. 021901. , (R) () PRVCAN 0556-2813 10.1103/PhysRevC.69.021901;Konzer, J., Wang, F., (2009) Nucl. Instrum. Meth., A606, p. 713. , NIMAER 0168-9002 10.1016/j.nima.2009.05.011Mishra, A.P., (2008) Phys. Rev. C, 77, p. 064902. , PRVCAN 0556-2813 10.1103/PhysRevC.77.064902;Alver, B., Roland, G., (2010) Phys. Rev. C, 81, p. 054905. , PRVCAN 0556-2813 10.1103/PhysRevC.81.054905Alver, B., Roland, G., (2010) Phys. Rev. C, 82, p. 039903. , 0556-2813 10.1103/PhysRevC.82.039903Xu, J., Ko, C.M., (2011) Phys. Rev. C, 84, p. 014903. , PRVCAN 0556-2813 10.1103/PhysRevC.84.014903Petersen, H., (2010) Phys. Rev. C, 82, p. 041901. , PRVCAN 0556-2813 10.1103/PhysRevC.82.041901Takahashi, J., (2009) Phys. Rev. Lett., 103, p. 242301. , PRLTAO 0031-9007 10.1103/PhysRevLett.103.242301;Andrade, R.P.G., (2012) Phys. Lett. B, 712, p. 226. , PYLBAJ 0370-2693 10.1016/j.physletb.2012.04.044;Qian, W.L., (2013) Phys. Rev. C, 87, p. 014904. , PRVCAN 0556-2813 10.1103/PhysRevC.87.014904Schenke, B., Jeon, S., Gale, C., (2011) Phys. Rev. Lett., 106, p. 042301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.042301;Qiu, Z., Heinz, U.W., (2011) Phys. Rev. C, 84, p. 024911. , PRVCAN 0556-2813 10.1103/PhysRevC.84.024911;Song, H., (2011) Phys. Rev. Lett., 106, p. 192301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.192301;Schenke, B., Jeon, S., Gale, C., (2012) Phys. Rev. C, 85, p. 024901. , PRVCAN 0556-2813 10.1103/PhysRevC.85.024901;Schenke, B., Tribedy, P., Venugopalan, R., (2012) Phys. Rev. Lett., 108, p. 252301. , PRLTAO 0031-9007 10.1103/PhysRevLett.108.252301Adare, A., (2011) Phys. Rev. Lett., 107, p. 252301. , (PHENIX Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.107.252301Adamczyk, L., (2013) Phys. Rev. C, 88, p. 014904. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.88.014904Abelev, B.I., (2008) Phys. Rev. Lett., 101, p. 252301. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.101.252301Teaney, D., Yan, L., (2011) Phys. Rev. C, 83, p. 064904. , PRVCAN 0556-2813 10.1103/PhysRevC.83.064904Pandit, Y., (2013) J. Phys. Conf. Ser., 446, p. 012012. , (STAR Collaboration),. 1742-6596 10.1088/1742-6596/446/1/012012Ajitanand, N.N., (2005) Phys. Rev. C, 72, p. 011902. , PRVCAN 0556-2813 10.1103/PhysRevC.72.011902Agakishiev, G., (2012) Phys. Rev. C, 86, p. 064902. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.86.064902Adler, C., (2002) Phys. Rev. C, 66, p. 034904. , (STAR Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.66.034904Abelev, B.I., (2009) Phys. Rev. C, 80, p. 064912. , (STAR Collaboration), () PRVCAN 0556-2813 10.1103/PhysRevC.80.064912;Abelev, B.I., (2010) Phys. Rev. Lett., 105, p. 022301. , PRLTAO 0031-9007 10.1103/PhysRevLett.105.022301Adler, S.S., (2006) Phys. Rev. Lett., 97, p. 052301. , (PHENIX Collaboration), () PRLTAO 0031-9007 10.1103/PhysRevLett.97. 052301;Adare, A., (2008) Phys. Rev. C, 78, p. 014901. , (PHENIX Collaboration),. PRVCAN 0556-2813 10.1103/PhysRevC.78.014901Stoecker, H., (2005) Nucl. Phys. A, 750, p. 121. , NUPABL 0375-9474 10.1016/j.nuclphysa.2004.12.074;Casalderrey-Solana, J., Shuryak, E.V., Teaney, D., (2005) J. Phys. Conf. Ser., 27, p. 22. , 1742-6588 10.1088/1742-6596/27/1/003;Ruppert, J., Müller, B., (2005) Phys. Lett. B, 618, p. 123. , PYLBAJ 0370-2693 10.1016/j.physletb.2005.04.075Betz, B., (2010) Phys. Rev. Lett., 105, p. 222301. , PRLTAO 0031-9007 10.1103/PhysRevLett.105.222301;Ma, G.L., Wang, X.N., (2011) Phys. Rev. Lett., 106, p. 162301. , PRLTAO 0031-9007 10.1103/PhysRevLett.106.162301Abelev, B.I., (2009) Phys. Rev. Lett., 102, p. 052302. , (STAR Collaboration),. PRLTAO 0031-9007 10.1103/PhysRevLett.102.052302Adamczyk, L., (2014) Phys. Rev. Lett., 112, p. 122301. , (STAR Collaboration),. 10.1103/PhysRevLett.112.12230

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-

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation &lt;92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p&lt;0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p&lt;0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research