1. Jinghua Fu Institute of Particle Physics, CCNU, Wuhan TUHEP, Tsinghua University, Beijing On the Measurement of Event Mean Pt Fluctuations Motivation Analytical Considerations Monte Carlo Simulations Summary

2. 2/14 Transverse Momentum and Temperature Fluctuations Single event transverse momentum distribution from thermal model Transverse momentum fluctuations sensitive to temperature fluctuations

3. Aug09-15ISMD2005, kromeriz3/14 Experimental Event-by-Event Pt Fluctuation Measurements Event average pt fluctuations Observables

4. = - Observables

5. Measur ement sqrt(s N N )  T /, Most central  T /, At the peak PHENIX2001.8%3.7% STAR1301.7%3.8% CERES171.3%2.2% NA49170.6%1.7% J.T.Mitchell QM2004 Results from different experiments

6. Aug09-15ISMD2005, kromeriz6/14 ? Are they the same?

7. Aug09-15ISMD2005, kromeriz7/14 Analytical Considerations Variance of theoretical event mean pt Factorial moments (Fixed multiplicity) (Non-Fixed Multiplicity)

8. Aug09-15ISMD2005, kromeriz8/14 (1) Fixed Multiplicity

9. Aug09-15ISMD2005, kromeriz9/14 (2) Non-Fixed Multiplicity measure fluctuations of

10. Aug09-15ISMD2005, kromeriz10/14 HIJING Monte Carlo Simulations 2,000,000 min-bias Au-Au collision events pseudo-rapidity transverse momentum

11. 11/14 Fixed Multiplicity Multiplicity fixed at n=5,10,20,50,100, 200,500 Theoretical event mean transverse momentum fluctuations has a similar results as dynamical fluctuations of event average transverse momentum. In measuring event average transverse momentum fluctuations, the statistical contribution is dominant even for high multiplicity sample

12. 12/14 Non-Fixed Multiplicity Number of participants fixed from peripheral to central collisions at 10,50,100,150,200,250,300 Hijing simulations show that is large than for fixed number of participant event samples, their dependence on average multiplicity are similar

13. Aug09-15ISMD2005, kromeriz13/14 First and Second Order Moments First Order: Second Order:

14. Summary For fixed multiplicity For non-Fixed multiplicity and other similar observables can’t be directly related to Measure both of them in Ebye analysis Thanks ! References: PRC68,064904(2003) PRC72,017901(2005)

15. Aug09-15ISMD2005, kromeriz15/14 Summary Robust Variance: