A. Wetzler

Publications (125)172.38 Total impact

• Article: Search for deconfinement in NA49 at the CERN SPS

  Peter Seyboth, Collaboration, S. V. Afanasiev, T. Anticic, D. Barna, J. Bartke, R. A. Barton, L. Betev, H. Bialkowska, A. Billmeier, [......], D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranic, S. Wenig, A. Wetzler, I. KYoo, J. Zaranek, J. Zimanyi
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  ABSTRACT: Experiment NA49 at the CERN SPS uses a large acceptance detector for a systematic study of particle yields and correlations in nucleus-nucleus, nucleon-nucleus and nucleon-nucleon collisions. Preliminary results for Pb+Pb collisions at 40, 80 and 158 A⋅GeV beam energy shown and compared to measurements at lower and higher energies.
  Pramana 04/2012; 60(4):725-737. · 0.57 Impact Factor
• Article: Energy dependence of particle ratio fluctuations in central Pb+Pb collisions from √sNN=6.3 to 17.3 GeV

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], P. Szymanski, V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, I. K. Yoo
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  ABSTRACT: We present measurements of the energy dependence of event-by-event fluctuations in the K/π and (p+p̅ )/π multiplicity ratios in heavy-ion collisions at the CERN SPS. The particle ratio fluctuations were obtained for central Pb+Pb collisions at five collision energies, √sNN, between 6.3 and 17.3 GeV. After accounting for the effects of finite-number statistics and detector resolution, we extract the strength of nonstatistical fluctuations at each energy. For the K/π ratio, larger fluctuations than expected for independent particle production are found at all collision energies. The fluctuations in the (p+p̅ )/π ratio are smaller than expectations from independent particle production, indicating correlated pion and proton production from resonance decays. For both ratios, the deviation from purely statistical fluctuations shows an increase toward lower collision energies. The results are compared to transport model calculations, which fail to describe the energy dependence of the K/π ratio fluctuations.
  Phys. Rev. C. 04/2009; 79(4).
• Article: Energy dependence of ϕ meson production in central Pb+Pb collisions at √sNN=6 to 17 GeV

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, I. K. Yoo, J. Zimányi
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  ABSTRACT: ϕ meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and with microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies.
  Phys. Rev. C. 10/2008; 78(4).
• Article: Energy dependence of Λ and Ξ production in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV measured at the CERN Super Proton Synchrotron

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, J. Zimányi
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  ABSTRACT: Results on Λ,Λ̅ ,Ξ-, and Ξ̅ + production in central Pb+Pb reactions at 20A,30A,40A,80A, and 158A GeV are presented. The energy dependence of transverse mass spectra, rapidity spectra, and multiplicities is discussed. Comparisons to string hadronic models (UrQMD and HSD) and statistical hadron gas models are shown. Although the latter provide a reasonable description of all particle yields, the first class of models fails to match the Ξ- and Ξ̅ + multiplicities.
  Phys. Rev. C. 09/2008; 78(3).
• Source

  Available from: Predrag Buncic

  Article: Energy dependence of phi meson production in central Pb+Pb collisions at sqrt(s_nn) = 6 to 17 GeV

  C. Alt, T. Anticic, B Baatar, D Barna, J. Bartke, L Betev, H Bialkowska, C Blume, B Boimska, M Botje, [......], V Trubnikov, D Varga, M Vassiliou, G I Veres, G Vesztergombi, D Vranic, A. Wetzler, Z. Walodarczyk, I. K. Yoo, J. Zimanyi
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  ABSTRACT: Phi meson production is studied by the NA49 Collaboration in central Pb+Pb collisions at 20A, 30A, 40A, 80A and 158A GeV beam energy. The data are compared with measurements at lower and higher energies and to microscopic and thermal models. The energy dependence of yields and spectral distributions is compatible with the assumption that partonic degrees of freedom set in at low SPS energies.
  07/2008;
• Article: Bose-Einstein correlations of π-π- pairs in central Pb+Pb collisions at 20A,30A,40A,80A, and 158A GeV

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, J. Zimányi
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  ABSTRACT: Measurements of Bose-Einstein correlations of π-π- pairs in central Pb+Pb collisions were performed with the NA49 detector at the CERN Super Proton Synchroton for beam energies of 20A,30A,40A,80A, and 158A GeV. Correlation functions were measured in the longitudinally comoving “out-side-long” reference frame as a function of rapidity and transverse momentum in the forward hemisphere of the reaction. Radius and correlation strength parameters were obtained from fits of a Gaussian parametrization. The results show a decrease of the radius parameters with increasing transverse-momentum characteristic of strong radial flow in the pion source. No striking dependence on pion-pair rapidity or beam energy is observed. Static and dynamic properties of the pion source are obtained from simultaneous fits with a blast-wave model to radius parameters and midrapidity transverse-momentum spectra. Predictions of hydrodynamic and microscopic models of Pb+Pb collisions are discussed.
  Phys. Rev. C. 06/2008; 77(6).
• Source

  Available from: Roy Lacey

  Article: High transverse momentum hadron spectra at sqrt [s_ {NN}]= 17.3 GeV in Pb+ Pb and p+ p collisions

  C Alt, T Anticic, B Baatar, D Barna, J Bartke, L Betev, H Bia, C Blume, B Boimska, M Botje, [......], D Varga, M Vassiliou, G I Veres, G Vesztergombi, D Vrani, A Wetzler, Z W Lodarczyk, A Wojtaszek, I K Yoo, J Zimányi
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  ABSTRACT: Transverse momentum spectra up to 4.5 GeV/c around midrapidity of π ± , p, ¯ p, K ± in Pb+Pb reactions were measured at √ s N N = 17.3 GeV by the CERN-NA49 experiment. The nuclear mod-ification factors RAA for π ± and RCP for π ± , p, ¯ p, K ± were extracted and are compared to RHIC results at √ s N N = 200 GeV. The modification factor RAA shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor RCP , in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the π ± channel. The extracted RCP values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for π ± above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.
  04/2008;
• Article: High transverse momentum hadron spectra at √sNN=17.3 GeV in Pb+Pb and p+p collisions

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, J. Zimányi
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  ABSTRACT: Transverse momentum spectra up to 4.5 GeV/c around midrapidity of π±,p,p̅ , and K± in Pb+Pb reactions were measured at √sNN=17.3 GeV by the CERN-NA49 experiment. The nuclear modification factors RAA for π± and RCP for π±,p,p̅ ,K± were extracted and compared with results obtained at the BNL Relativistic Heavy Ion Collider (RHIC) at √sNN=200 GeV. The modification factor RAA shows a rapid increase with transverse momentum in the covered region. This indicates that the Cronin effect is the dominating effect in our energy range. The modification factor RCP, in which the contribution of the Cronin effect is reduced, shows a saturation well below unity in the π± channel. The extracted RCP values follow the 200 GeV RHIC results closely in the available transverse momentum range, except for π± above 2.5 GeV/c transverse momentum. There the measured suppression is smaller than that observed at RHIC.
  Phys. Rev. C. 03/2008; 77(3).
• Article: Pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV: Evidence for the onset of deconfinement

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], V. Trubnikov, D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, I. K. Yoo, J. Zimányi
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  ABSTRACT: Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.
  Phys. Rev. C. 02/2008; 77(2).
• Article: Rapidity and species dependence of particle production at large transverse momentum for d+Au collisions at √sNN=200 GeV

  B. I. Abelev, J. Adams, M. M. Aggarwal, Z. Ahammed, J. Amonett, B. D. Anderson, M. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, [......], H. Zhang, W. M. Zhang, Y. Zhang, Z. P. Zhang, Y. Zhao, C. Zhong, R. Zoulkarneev, Y. Zoulkarneeva, A. N. Zubarev, J. X. Zuo
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  ABSTRACT: We determine rapidity asymmetry in the production of charged pions, protons, and antiprotons for large transverse momentum (pT) for d+Au collisions at √sNN=200 GeV. The rapidity asymmetry is defined as the ratio of particle yields at backward rapidity (Au beam direction) to those at forward rapidity (d beam direction). The identified hadrons are measured in the rapidity regions |y|<0.5 and 0.5<|y|<1.0 for the pT range 2.5<pT<10 GeV/c. We observe significant rapidity asymmetry for charged pion and proton+antiproton production in both the rapidity regions. The asymmetry is larger for 0.5<|y|<1.0 than for |y|<0.5 and is almost independent of particle type. The measurements are compared to various model predictions employing multiple scattering, energy loss, nuclear shadowing, saturation effects, and recombination and also to a phenomenological parton model. We find that asymmetries are sensitive to model parameters and show model preference. The rapidity dependence of π-/π+ and p̅ /p ratios in peripheral d+Au and forward neutron-tagged events are used to study the contributions of valence quarks and gluons to particle production at high pT.
  Phys. Rev. C. 11/2007; 76(5).
• Article: Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV.

  B I Abelev, M M Aggarwal, Z Ahammed, B D Anderson, D Arkhipkin, G S Averichev, Y Bai, J Balewski, O Barannikova, L S Barnby, [......], W M Zhang, Y Zhang, Z P Zhang, Y Zhao, C Zhong, J Zhou, R Zoulkarneev, Y Zoulkarneeva, A N Zubarev, J X Zuo
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  ABSTRACT: We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.
  Physical Review Letters 10/2007; 99(11):112301. · 7.37 Impact Factor
• Source

  Available from: Roy Lacey

  Article: Event-by-event transverse momentum fluctuations in nuclear collisions at CERN SPS

  K Grebieszkow, C. Alt, T. Anticic, B Baatar, D Barna, J. Bartke, L Betev, H Białkowska, C Blume, B Boimska, [......], D Varga, M Vassiliou, G I Veres, G Vesztergombi, D Vranić, A. Wetzler, Z Włodarczyk, A Wojtaszek, I. K. Yoo, J Zimányi
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  ABSTRACT: The latest NA49 results on event-by-event transverse momentum fluctuations are presented for central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV). Two different methods are applied: evaluating the $\Phi_{p_{T}}$ fluctuation measure and studying two-particle transverse momentum correlations. The obtained results are compared to predictions of the UrQMD model. The results on the energy dependence are compared to the NA49 data on the system size dependence. The NA61 (SHINE, NA49-future) strategy of searching of the QCD critical end-point is also discussed.
  08/2007;
• Article: Partonic Flow and ϕ-Meson Production in Au+Au Collisions at sNN=200GeV

  B. I. Abelev, M. M. Aggarwal, Z. Ahammed, B. D. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. S. Barnby, [......], W. M. Zhang, Y. Zhang, Z. P. Zhang, Y. Zhao, C. Zhong, J. Zhou, R. Zoulkarneev, Y. Zoulkarneeva, A. N. Zubarev, J. X. Zuo
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  ABSTRACT: We present first measurements of the ϕ-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from sNN=200GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the ϕ meson is consistent with the trend observed for mesons. The ratio of the yields of the Ω to those of the ϕ as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT˜4GeV/c, but disagrees at higher momenta. The nuclear modification factor (RCP) of ϕ follows the trend observed in the KS0 mesons rather than in Λ baryons, supporting baryon-meson scaling. These data are consistent with ϕ mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.
  Physical Review Letters 08/2007; 99(11):112301. · 7.37 Impact Factor
• Article: Rapidity and energy dependence of the electric charge correlations in A+A collisions from 20A to 158A GeV

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, J. Zimányi
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  ABSTRACT: Results from electric charge correlations studied with the Balance Function (BF) method in A+A collisions from 20A to 158A GeV are presented in two different rapidity intervals: In the midrapidity region we observe a decrease of the width of the BF distribution with increasing centrality of the collision, whereas this effect vanishes in the forward rapidity region. Results from the energy dependence study in central Pb+Pb collisions show that the narrowing of the BF expressed by the normalized width parameter W increases with energy toward the highest CERN Super Proton Synchrotron and BNL Relativistic Heavy Ion Collider energies. Finally we compare our experimental data points with the predictions of several models. The hadronic string models Ultra-relativistic Quantum Molecular Dynamics and Heavy Ion Jet INteraction Generator (HIJING) do not reproduce the observed narrowing of the BF. However, A MultiPhase Transport medel (AMPT), which contains a quark-parton transport phase before hadronization, can reproduce the narrowing of the BF's width with centrality. This confirms the proposed sensitivity of the BF analysis to the time of hadronization.
  Phys. Rev. C. 08/2007; 76(2).
• Article: Centrality and system size dependence of multiplicity fluctuations in nuclear collisions at 158A GeV

  C. Alt, T. Anticic, B. Baatar, D. Barna, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, M. Botje, [......], D. Varga, M. Vassiliou, G. I. Veres, G. Vesztergombi, D. Vranić, A. Wetzler, Z. Włodarczyk, A. Wojtaszek, I. K. Yoo, J. Zimńyi
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  ABSTRACT: The centrality and system size dependence of multiplicity fluctuations of charged particles produced in nuclear collisions at 158A GeV was studied by the NA49 Collaboration. Centrality selected Pb+Pb collisions, semicentral C+C and Si+Si collisions as well as inelastic p+p interactions were analyzed. The number of projectile participants determined on an event-by-event basis was used to characterize the collision centrality. The scaled variance of the multiplicity distribution obtained in the forward rapidity region (1.1<yc.m.<2.6) shows a significant increase toward peripheral collisions. The results are similar for negatively and positively charged particles and about 50% larger for all charged particles. String-hadronic models of nuclear reactions without the fusion process do not reproduce the rise of fluctuations from central toward peripheral collisions. The measured centrality dependence can be reproduced in superposition models with the assumption of contributions from target participants to particle production in the forward hemisphere or in string models with fusion.
  Phys. Rev. C. 06/2007; 75(6).
• Article: Mass, quark-number, and √sNN dependence of the second and fourth flow harmonics in ultrarelativistic nucleus-nucleus collisions

  B. I. Abelev, M. M. Aggarwal, Z. Ahammed, B. D. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, O. Barannikova, L. S. Barnby, [......], W. M. Zhang, Y. Zhang, Z. P. Zhang, Y. Zhao, C. Zhong, J. Zhou, R. Zoulkarneev, Y. Zoulkarneeva, A. N. Zubarev, J. X. Zuo
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  ABSTRACT: We present STAR measurements of the azimuthal anisotropy parameter v2 for pions, kaons, protons, Λ,Λ̅ ,Ξ+Ξ̅ , and Ω+Ω̅ , along with v4 for pions, kaons, protons, and Λ+Λ̅ at midrapidity for Au+Au collisions at √sNN=62.4 and 200 GeV. The v2(pT) values for all hadron species at 62.4 GeV are similar to those observed in 130 and 200 GeV collisions. For observed kinematic ranges, v2 values at 62.4, 130, and 200 GeV are as little as 10–15% larger than those in Pb+Pb collisions at √sNN=17.3 GeV. At intermediate transverse momentum (pT from 1.5–5 GeV/c), the 62.4 GeV v2(pT) and v4(pT) values are consistent with the quark-number scaling first observed at 200 GeV. A four-particle cumulant analysis is used to assess the nonflow contributions to pions and protons and some indications are found for a smaller nonflow contribution to protons than pions. Baryon v2 is larger than antibaryon v2 at 62.4 and 200 GeV, perhaps indicating either that the initial spatial net-baryon distribution is anisotropic, that the mechanism leading to transport of baryon number from beam- to midrapidity enhances v2 or that antibaryon and baryon annihilation is larger in the in-plane direction.
  Phys. Rev. C. 05/2007; 75(5).
• Source

  Available from: Issam Qattan

  Article: Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV.

  B I Abelev, M M Aggarwal, Z Ahammed, B D Anderson, D Arkhipkin, G S Averichev, Y Bai, J Balewski, O Barannikova, L S Barnby, [......], W M Zhang, Y Zhang, Z P Zhang, Y Zhao, C Zhong, J Zhou, R Zoulkarneev, Y Zoulkarneeva, A N Zubarev, J X Zuo
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  ABSTRACT: The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.
  Physical Review Letters 05/2007; 98(19):192301. · 7.37 Impact Factor
• Article: Two-particle correlations on transverse momentum and momentum dissipation in Au–Au collisions at = 130 GeV

  The STAR Collaboration, J Adams, M M Aggarwal, Z Ahammed, J Amonett, B D Anderson, M Anderson, D Arkhipkin, G S Averichev, Y Bai, [......], H Zhang, W M Zhang, Y Zhang, Z P Zhang, Y Zhao, C Zhong, R Zoulkarneev, Y Zoulkarneeva, A N Zubarev, J X Zuo
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  ABSTRACT: Measurements of two-particle correlations on transverse momentum pt for Au–Au collisions at GeV are presented. Significant large-momentum-scale correlations are observed for charged primary hadrons with 0.15 ≤ pt ≤ 2 GeV/c and pseudorapidity |η| ≤ 1.3. Such correlations were not observed in a similar study at lower energy and are not predicted by theoretical collision models. Their direct relation to mean-pt fluctuations measured in the same angular acceptance is demonstrated. Positive correlations are observed for pairs of particles which have large pt values while negative correlations occur for pairs in which one particle has large pt and the other has much lower pt. The correlation amplitudes per final state particle increase with collision centrality. The observed correlations are consistent with a scenario in which the transverse momentum of hadrons associated with initial-stage semi-hard parton scattering is dissipated by the medium to lower pt.
  Journal of Physics G Nuclear and Particle Physics 03/2007; 34(5):799. · 4.18 Impact Factor
• Article: ΔϕΔη correlations in central Au+Au collisions at √sNN=200 GeV

  J. Adams, M. M. Aggarwal, Z. Ahammed, J. Amonett, B. D. Anderson, M. Anderson, D. Arkhipkin, G. S. Averichev, Y. Bai, J. Balewski, [......], H. Zhang, W. M. Zhang, Y. Zhang, Z. P. Zhang, Y. Zhao, C. Zhong, R. Zoulkarneev, Y. Zoulkarneeva, A. N. Zubarev, J. X. Zuo
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  ABSTRACT: We report charged particle pair correlation analyses in the space of Δϕ (azimuth) and Δη (pseudorapidity), for central Au+Au collisions at √sNN=200 GeV in the STAR detector. The analysis involves unlike-sign charged pairs and like-sign charged pairs, which are transformed into charge-dependent (CD) signals and charge-independent (CI) signals. We present detailed parametrizations of the data. A model featuring dense gluonic hot spots as first proposed by Van Hove predicts that the observables under investigation would have sensitivity to such a substructure should it occur, and the model also motivates selection of transverse momenta in the range 0.8<pt<2.0 GeV/c. Both CD and CI correlations of high statistical significance are observed, and possible interpretations are discussed.
  Phys. Rev. C. 03/2007; 75(3).
• Article: Inclusive production of charged pions in p + C collisions at 158 GeV/c beam momentum

  C. Alt, B. Baatar, D. Barna, G. Barr, J. Bartke, L. Betev, H. Białkowska, C. Blume, B. Boimska, J. Bracinik, [......], V. Trubnikov, D. Varga, M. Vassiliou, G.I. Veres, G. Vesztergombi, D. Vranić, S. Wenig, A. Wetzler, J. Zaranek, The NA Collaboration
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  ABSTRACT: The production of charged pions in minimum bias p+C interactions is studied using a sample of 377000 inelastic events obtained with the NA49 detector at the CERN SPS at 158GeV/c beam momentum. The data cover a phase space area ranging from 0 to 1.8GeV/c in transverse momentum and from -0.1 to 0.5 in Feynman xF. Inclusive invariant cross sections are given on a grid of 270 bins per charge, thus offering for the first time a dense coverage of the projectile hemisphere and of the cross-over region into the target fragmentation zone.
  European Physical Journal C 02/2007; 49(4):897-917. · 3.63 Impact Factor