Oct 14 – 17, 2009
Europe/Zurich timezone
This page is a work in progress...

Further study on the ridge effect in hydrodynamic model

Oct 15, 2009, 11:20 AM
TH Auditorium (CERN)

TH Auditorium


Talk Investigating Dynamics and the EOS with Correlations Dynamics and the Equation of State (2/2)


Y. Hama (Instituto de Fisica - USP)


In a recent paper [1], the hydrodynamic code NeXSPheRIO was used in conjunction with STAR analysis methods to study two-particle correlations as function of \Delta\eta and \Delta\phi. Both the ridge-like near-side and double-hump away-side structures were obtained. The appearance of the ridge-like structure is related to the combined effect of high-energy density tubes in the initial conditions and the transverse expansion of the fluid. As far as the near-side ridge is concerned, this statement can easily be accepted, if some high-density tubes are located close to the surface of the hot matter. As for the less trivial away-side structure, made of double ridges placed symmetrically with respect to the high-pT trigger in the most central collisions, it is hard to understand. A closer look at the flow produced in the neighborhood of such a tube, showed that actually the ridge structure in our hydrodynamics, both nearside and the away-side, is due to a peculiar flow effect of interference between the peripheral high-energy tubes and the backgound hot matter in expansion. The pT-dependence of the two-particle correlation function in \Delta\phi, produced by this mechanism, is similar to the PHENIX data [3]. We have further studied this mechanism, computing the three-particle correlation, which may discriminate between this and the popular Mach cone mechanism [4]. References: [1] J. Takahashi et al. arXiv:0902.4870. [2] R. Andrade, F. Grassi, Y. Hama and W.-L. Qian, communication to ISMD2009. [3] A.Adare et al., Phys.Rev.C77 (2008)011901(R); Phys.Rev.C78 (2008) 014901. [4] J. Casalderrey-Solana, E.V. Shurayk, D. Teaney, hep-ph/0602183; J. Ruppert and T. Renk, Acta Phys. Polon. Supp. 1, 633 (2008).

Primary author

Y. Hama (Instituto de Fisica - USP)


F. Grassi (Instituto de Fisica - USP) R. Andrade (Instituto de Fisica - USP) W. Qian (Instituto de Fisica - USP)

Presentation materials