1 / 15

Collective motion of Xe-Xe collision at CSR energy

Collective motion of Xe-Xe collision at CSR energy. Xie Fei, Wu Kejun, Liu Feng ccnu Institute of Particle Physics. Outline. Motivation Result and discussion Centrality selection Baryon density evolution Collective flow Thermalization and m T spectra Summary. 1. Motivation.

jesus
Download Presentation

Collective motion of Xe-Xe collision at CSR energy

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Collective motion of Xe-Xe collision at CSR energy Xie Fei, Wu Kejun, Liu Feng ccnu Institute of Particle Physics

  2. Outline • Motivation • Result and discussion • Centrality selection • Baryon density evolution • Collective flow • Thermalization and mT spectra • Summary

  3. 1. Motivation Matter Compression: Vacuum Heating: Deconfinement CSR energy High Baryon Density -- low energy collisions -- neutron starquark star High Temperature Vacuum -- high energy collisions -- the Big Bang

  4. HIRFL-CSR SFC: up to 10 AMeV SSC: up to 100 AMeV North Building 2# SSC SFC CSRe CSRm 1. Motivation The Heavy Ion Research Facility in Lanzhou (HIRFL) Cooler Storage Ring (CSR) CSRm: 500AMeV~1000AMeV Status and Prospects of HIRFL Experiments Hushan Xu

  5. ETF Phase I(External Target Facility – Phase I) Z.G. Xiao SQM2008 • For RIB Physics mainly •  detectors:4 segmented Clover detectors • ToF Wall:3, 2 layers of BC408 bars, 30 bars/layer, readout fromboth ends with PMT (R7525) • Neutron Wall:14 layers, 18 paddles/layer, readout from both ends with PMT (R7724); BC408 only for the first two layers, sampling type (BC408+Fe) for the others • MWDC:6, with conventional technique

  6. Key part！！ ETF Phase II • New Detectors • -ball • (CsI(Tl) array • MWPC • (inside dipole) • Si-strip array • (inside dipole) • TPC? • (at target region) • Possible Physics • For RIB Physics • For EoS of asymmetry nuclear matter • For high baryon density matter

  7. 2.1 Centrality selection • Two methods: • The multiplicity of forward neutrons with polar angle θ < 15◦ in the laboratory frame. • 2. The multiplicity of charge particles Nch with mid-rapidity • linear dependence of the impact parameter b

  8. 2.2 Baryon density R 5.7fm 6.3fm Short (b -b) 5.8fm Long (t -t) 9.4fm

  9. z y x 2.3 Collective flow(1) v1 flow parameter:

  10. 2.3 Collective flow(2) In ART model: Mean field: are all functions of K Soft : K=201MeV Stiff : K=377MeV Cascade : no mean field Flow parameter is sensitive to EOS.

  11. 2.3 Collective flow(3) Jean-Yves Ollitraulta arXiv:nucl-ex/9802005 v1 12 Feb 1998 At CSR energy region, around 500~1000MeV/u, it has very rich flow information, i.e. collision dynamics information. CSR energy

  12. 2.3 Collective flow(4) F will get the maximum at about b/bmax=0.2 for different elements bmax Cu 9fm Xe 12fm Pb 14fm

  13. 60~80% 40~60% 10~30% 0~10% The Charge Multiplicity Nch 2.4 Thermalization and mT spectra(1)

  14. 2.4 Thermalization and mT spectra(2) (a) proton (b) pion

  15. Summary • We can use forward Neutron or Nch to determine the collision centrality • v1 flow is sensitive to the EOS and system size • Anisotropy flow reach its extremum at CSR energy range. The turnings contain rich dynamic information. This energy region is well worth studying for flow. • Radial collective motion is stronger at central collisions.

More Related