Production of Phi meson at 62'4GeV AuAu Collisions

1
Production of Phi meson at 62.4GeV AuAu
Collisions
Outlines 1.Dataset , cut method 2.Centroid
Width 3.Correction Factor 4.Spectra 5.Conclusion

• Shengli Huang
• Vanderbilt University

2
The dataset, cuts and methods

• DataSet 62.4GeV AuAu
• full field --
• Centrality083.7
• VertexZlt30cm
• The total events 34M
• Kaon selections
• Quality 3163
• Momemtum Cut
• EMCal momlt2.5GeV/c
• TOFw momlt4.0GeV/c
• Ghost and intruder tracks are kicked out

• Mixing event methods
• 8 centrality bins
• 6 VertexZ bins
• 10 mixing events
• Normalization methods
• 1)AkibaNevents/Nmixevents
• 2)Hemmick2sqrt(NN--)
• 3)Integral yield(m0gt1.10GeV)

3
The Phi signal Centroid Width

• Min-Bias
• Fit Function Breit-wigner
• with Gaussian mass resolution
• of 1.4MeV
• Width
• 4.61 0.46(sta) 0.58(sys)MeV
• Centroid
• 1.0200.0002(sta) 0.0009(sys)GeV
• Consistent with PDG value

4
The Centroid Width _at_Centrality
The centroid and width of phi meson have not
centrality dependence
5
Correction Factor(I)
6
Correction Factor(II)
Embedding Results
Run-by-Run reference 123202
7
Spectra

• The invariant yield of phi
• meson as a function of mT
• at three different centrality
• The error is statistic error
• only. The systematic error
• is about 3. It mainly
• come from different fit
• region and normal methods
• Fit function

8
dN/dy_at_centrality
The 1/0.5Npartdn/dy at 62GeV AuAu is smaller than
200GeV AuAu They both increase from peripheral
collision and saturates at central collision.
9
T Slope_at_centrality
The T slope of phi meson at 62GeV is smaller than
200GeV. They both do not show centrality
difference.
10
Conclusions
1.The production of phi in 62.4GeV AuAu
collision has been studied. 2.The centroid
width of phi meson do not show clear centrality
dependence 3.The T slope 1/0.5Npartdn/dy at
62GeV AuAu are smaller than 200GeV. At these two
energy, the T does not show centrality
dependence, while 1/0.5Npartdn/dy has a little
increase from peripheral to central collisions
11
The Phi signal Centroid Width
3.Integral4.03 0.44MeV
1.Akiba 4.610.46MeV

• Min-Bias
• Width
• 4.61 0.46(sta) 0.58(sys)MeV
• Centroid
• 1.0200.0002(sta) 0.0009(sys)GeV
• Consistent with PDG value

2.Hemmick4.93 0.47MeV