Tue·Jul 5, 2011Tuesday·July 5, 2011

1. 01*

   Elliptic flow at high transverse momentum in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV with the ALICE experiment

   A. Dobrin (for the ALICE Collaboration)🇺🇸

   An observable that can be used to better constrain the mechanism responsible for the parton energy loss is the elliptic azimuthal event anisotropy, $v_2$. We report on measurements of $v_2$ for inclusive and identified charged particles in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV recorded by the ALICE experiment at the LHC. $v_2$ is presented for a wide range of particle transverse momentum up to $p_T=20$ GeV/c. The particle $v_2$ is finite, positive and approximately constant for $p_T>8$ GeV/c. The proton $v_2$ is higher than that of the pion up to about $p_T=8$ GeV/c. The results are compared to the measurements at lower energy reported by RHIC experiments.

   nucl-exJ.Phys.G(2011)·12 citations
2. 02*

   Centrality dependence of charged particle spectra and RCP in Pb+Pb collisions at \sqrt{s_{NN}}=2.76TeV with the ATLAS detector at the LHC

   Alexander Milov (for the ATLAS Collaboration)🇮🇱

   The ATLAS experiment at the LHC measures the charged particle spectra and the nuclear modification factor in Pb+Pb collisions at the \sqrt{s_{NN}}=2.76TeV in a transverse momentum range up to 30 GeV and a pseudorapidity range up to |\eta| < 2.5. The measurement reveals the strong suppression of charged hadron production in the most central collisions at a p_T of about 7 GeV. A suppression of more than a factor of 2 is also measured at the upper edge of the analyzed p_T range. The suppression does not show any strong \eta dependence.

   nucl-exJ.Phys.G(2011)·16 citations
3. 03*

   Two-pion Bose-Einstein correlations in Pb-Pb collisions at 2.76 TeV with ALICE

   Jorge Mercado🇩🇪

   We present the first measurement of pion source radii in Pb-Pb collisions at the LHC. The radii were obtained by analyzing the Bose-Einstein enhancement in two-pion correlation functions. Like at lower energies, the radii drop with increasing transverse momentum, indicating presence of collective expansion. In absolute terms, all three radii (Rout, Rside, Rlong) are larger than at RHIC, roughly consistent with a linear scaling with the cube root of the particle multiplicity.

   nucl-exhep-exJ.Phys.G(2011)·4 citations
4. 04*

   Hadron Correlations in Pb-Pb collisions at sqrt(s_NN) = 2.76 TeV with ALICE

   Jan Fiete Grosse-Oetringhaus (for the ALICE collaboration)🇨🇭

   Untriggered di-hadron correlations studies are shown which provide a map of the bulk correlation structures in Pb-Pb collisions. Long-range correlations are further studied by triggered correlations which address the dependence on trigger and associated pT. Measured correlation functions are decomposed with a multi-parameter fit and into Fourier coefficients. The jet-yield modification factor I_AA is presented.

   nucl-exhep-exJ.Phys.G(2011)·11 citations
5. 05*

   J/psi production at sqrt(s)=1.96 and 7 TeV: Color-Singlet Model, NNLO* and polarisation

   J.P. Lansberg🇫🇷

   We study J/psi production in pp collisions at sqrt(s)=1.96 and 7 TeV using the Colour-Singlet Model (CSM), including next-to-leading order (NLO) corrections and dominant alphaS^5 contributions (NNLO*). We find that the CSM reproduces the existing data if the upper range of the NNLO* is near the actual --but presently unknown-- NNLO. The direct yield polarisation for the NLO and NNLO* is increasingly longitudinal in the helicity frame when P_T gets larger. Contrary to what is sometimes claimed in the literature, the prompt J/psi yield polarisation in the CSM is compatible with the experimental data from the CDF collaboration, when one combines the direct yield with a data-driven range for the polarisation of J/psi from chi(c).

   ↳ hep-phhep-exnucl-exnucl-thJ.Phys.G(2011)·53 citations
6. 06*

   How to Improve UrQMD Model to Describe NA61/SHINE Experimental Data

   V. Uzhinsky🇨🇭

   The NA61/SHINE collaboration measured inclusive cross sections of pi+ and pi- meson production in the interactions of 31 GeV/c proton with carbon nuclei at small emission angles (0 - 420 mrad). The collaboration presented also predictions of Monte Carlo models - FLUKA, VENUS and UrQMD, in a comparison with the data. The worst description of the data was observed for UrQMD model results. In the present paper it is shown that the drawback of the UrQMD model is connected with an inaccurate treatment of low mass string fragmentation. The strings appeared at a diffraction of target nucleons. A simple patch is proposed to overcome the problem.

   ↳ hep-phhep-exnucl-exnucl-th15 citations
7. 07*

   Short-range tensor interaction and high-density nuclear symmetry energy

   Ang Li🇨🇳 · Bao-An Li🇺🇸

   Effects of the short-range tensor interaction on the density-dependence of nuclear symmetry energy are examined by applying an approximate expression for the second-order tensor contribution to the symmetry energy derived earlier by G.E. Brown and R. Machleidt. It is found that the uncertainty in the short-range tensor force leads directly to a divergent high-density behavior of the nuclear symmetry energy.

   ↳ nucl-thnucl-ex12 citations
8. 08*

   J/psi production and correlation in p+p and Au+Au collisions at STAR

   Zebo Tang (for the STAR Collaboration)🇨🇳

   The results on J/psi pT spectra in 200 GeV p+p and Au+Au collisions at STAR with pT in the range of 3-10 GeV/c are presented. Nuclear modification factor of high-pT J/psi is found to be consistent with no suppression in peripheral Au+Au collisions and significantly smaller than unity in central Au+Au collisions. The J/psi elliptic flow is measured to be consistent with no flow at pT < 10 GeV/c in 20-60% Au+Au collisions.

   ↳ hep-exnucl-exJ.Phys.G(2011)·54 citations
9. 09*

   Flow fluctuations and long-range correlations: elliptic flow and beyond

   Matthew Luzum🇫🇷

   These proceedings consist of a brief overview of the current understanding of collective behavior in relativistic heavy-ion collisions. In particular, recent progress in understanding the implications of event-by-event fluctuations have solved important puzzles in existing data -- the "ridge" and "shoulder" phenomena of long-range two-particle correlations -- and have created an exciting opportunity to tightly constrain theoretical models with many new observables.

   ↳ nucl-thhep-phnucl-exJ.Phys.G(2011)·104 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.