Pion HBT in AuAu@19.6 GeV

    Paper proposal : Pion HBT in AuAu@19.6 GeV  - presentation at Convenior's meeting - 11-09-2007

Abstract

We present  results of identical pion correlations in Au+Au collisions at √sNN = 19.6 GeV from the STAR experiment at RHIC. This analysis is sensitive to a long system lifetime which has been proposed as a signal of the onset of a phase transition to QGP. This is particularly interesting as possible QGP-onset signals have been reported at energies close to that studied. Our results are consistent with baseline expectations and disfavor large-lifetime scenarios.

Blast-Wave fit to spectra and HBT

Blast-Wave fit to spectra and HBT in AuAu @ 19.6 GeV

Figures

Figures that go into paper

Figure 1

Figure 1: Cartesian projections of the CF for the first kT bin for the most central AuAu@19.6GeV

 (non-projected Q-components < 0.04 GeV/c)

Figure 2

Figure 2: mT dependence : RHIC/AGS/SPS systematics

Figure 3

Figure: mT dependence of HBT radii from CERES, NA49 & STAR.


STAR data : most central AuAu@19.6 GeV [preliminary]

kT bin [GeV/c]
 <mT> [GeV] Rout [fm] Rside [fm] Rlong [fm] λ
[0.15,0.25] 0.240  4.84 ± 0.44  4.94 ± 0.42  5.87 ± 0.49  0.43 ± 0.07
[0.25,0.35] 0.328  4.97 ± 0.27  4.71 ± 0.24  4.99 ± 0.27  0.53 ± 0.04
[0.35,0.45] 0.420  4.46 ± 0.28  4.29 ± 0.26  4.10 ± 0.29  0.60 ± 0.07
[0.45,0.60] 0.522  3.37 ± 0.36  3.76 ± 0.31  3.35 ± 0.37  0.45 ± 0.07


CERES PbPb@17.3 GeV

<mT> [GeV] Rout [fm] Rside [fm] Rlong [fm]
0.183  5.833 ± 0.075  5.348 ± 0.060  6.996 ± 0.090
0.238  5.600 ± 0.049  4.865 ± 0.040  5.849 ± 0.054
0.323  4.963 ± 0.079  4.566 ± 0.061  4.889 ± 0.071
0.416  4.349 ± 0.144  4.252 ± 0.094  4.134 ± 0.105
0.572  3.538 ± 0.191  3.926 ± 0.103  3.620 ± 0.113

NA49 PbPb@17.3 GeV [ArXiv:0709.4507v2]  

<mT> [GeV] Rout [fm] Rside [fm] Rlong [fm]
0.152 6.06 ± 0.06 5.59 ± 0.05 7.95 ± 0.09
0.205 5.90 ± 0.06 5.25 ± 0.05 6.65 ± 0.07
0.286 5.29 ± 0.08 4.66 ± 0.06 5.19 ± 0.08
0.377 4.99 ± 0.10 4.42 ± 0.07 4.45 ± 0.08
0.500 5.05 ± 0.12 4.17 ± 0.09 3.85 ± 0.09

Figure 3 (old)

Figure: mT dependence of HBT radii from CERES, NA49 & STAR. (OLD - includes NA49 data from QM2004)


STAR data : most central AuAu@19.6 GeV [preliminary]

kT bin [GeV/c]
 <mT> [GeV] Rout [fm] Rside [fm] Rlong [fm] λ
[0.15,0.25] 0.240  4.84 ± 0.44  4.94 ± 0.42  5.87 ± 0.49  0.43 ± 0.07
[0.25,0.35] 0.328  4.97 ± 0.27  4.71 ± 0.24  4.99 ± 0.27  0.53 ± 0.04
[0.35,0.45] 0.420  4.46 ± 0.28  4.29 ± 0.26  4.10 ± 0.29  0.60 ± 0.07
[0.45,0.60] 0.522  3.37 ± 0.36  3.76 ± 0.31  3.35 ± 0.37  0.45 ± 0.07


CERES PbPb@17.3 GeV

<mT> [GeV] Rout [fm] Rside [fm] Rlong [fm]
0.183  5.833 ± 0.075  5.348 ± 0.060  6.996 ± 0.090
0.238  5.600 ± 0.049  4.865 ± 0.040  5.849 ± 0.054
0.323  4.963 ± 0.079  4.566 ± 0.061  4.889 ± 0.071
0.416  4.349 ± 0.144  4.252 ± 0.094  4.134 ± 0.105
0.572  3.538 ± 0.191  3.926 ± 0.103  3.620 ± 0.113

NA49 PbPb@17.3 GeV [preliminary QM 2004]  

<mT> [GeV] Rout [fm] Rside [fm] Rlong [fm]
0.158 5.80 5.35 7.80
0.198 6.00 5.00 6.60
0.286 5.60 4.35 5.00
0.377 5.10 4.05 4.20
0.470 5.61 4.10 3.90

* values taken directly from the figure so there is no errors

Figure 4

Figure 4: Ri=o,s,l ~ 1/(mTαi) fit (symbols as in Fig. 2)

Figure 5

Figure 5: HBT excitation function

(what to do with STAR unpublished AuAu62GeV data?)