Wed·Jul 15, 2009Wednesday·July 15, 2009

1. 01*

   Event anisotropy $v_2$ at STAR

   Shusu Shi (for the STAR Collaboration)🇨🇳

   Collective flow reflects the dynamical evolution in high-energy heavy ion collisions. In particular, the elliptic flow reflects early collision dynamics.We present a systematic analysis of elliptic flow ($v_2$) for identified particles measured in Au + Au and Cu + Cu collisions at $\sqrt{s_{NN}}$ = 200 GeV. Number of quark scaling is tested in the intermediate $p_T$ region and in the smaller system (Cu + Cu). The Cu + Cu collisions results are compared with those from ideal hydrodynamic model calculations.

   nucl-exhep-exNPA(2009)·22 citations
2. 02*

   Photoproduction at the Relativistic Heavy Ion Collider with STAR

   Yury Gorbunov (for the STAR collaboration)🇺🇸

   The strong electromagnetic fields of short duration associated with relativistic heavy ions make a heavy-ion collider a unique tool to study two-photon and photonuclear collisions. In this talk, we introduce the principles of photoproduction at hadron colliders, review recent results from RHIC on meson and e${}^{+}$e${}^{-}$ production. At RHIC, STAR has studied exclusive ${\rho }^0$ vector meson production and ${\rho }^0$ production accompanied by electromagnetic dissociation of both nuclei in collisions of AuAu at 62, 130 and 200 GeV. Recent results suggest the validity of the Glauber calculations for the vector meson photoproduction and incosistency of the model based on the parton saturation phenomenon. The measurements are a lso sensitive to interference between production on the two nuclei: either ion can be the photon emitter or the target. The level of observed interference suggests that the final state wave function carries information about all possible decays long after the decay occurs. We also observe coherent photoproduction of a ${\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ state which may be associated with ${\rho }^{0\ast }$ (1450).

   nucl-exNPA(2009)·1 citation
3. 03*

   Hadrons in strongly interacting matter

   Stefan Leupold🇩🇪 · Volker Metag🇩🇪 · Ulrich Mosel🇩🇪

   We review the current status of theories and experiments aiming at an understanding and a determination of the properties of light vector and scalar mesons inside strongly interacting hadronic matter. Starting from a discussion of the relevant symmetries of QCD and their connection with the hadronic description through QCD sum rules we then discuss hadronic models used to calculate the in-medium self-energies of hadrons and their spectral functions. The difficulties to link these calculated properties to actual observables are emphasized. Finally, we review in detail all the running experiments searching for in-medium changes of vector and scalar mesons, both with relativistic heavy-ion reactions as well as with elementary reactions on (cold) nuclei. Inconsistencies among experimental results are discussed. While almost all experiments observe a considerable broadening of vector mesons inside the nuclear medium, no evidence for mass changes is observed in the majority of the experiments.

   ↳ nucl-thhep-phnucl-exIJMPE(2010)·221 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.