1. 1 Jan Rak6/14/2015 kT, jT, and xE from pi0 and gamma associated spectra, Run 5 Jyvaskyla Jan, DongJo, M. Bondila, Timo Alho For spin - UNM - Imran, Doug

2. 2 Jan Rak6/14/2015 The goal of this analysis:  Repeat a similar analysis as presented in ppg029 (run03 data) with run05 larger data sample. Extend the physics scope of ppg029 (with run05 the pT reach is obviously higher, allows to explore e.g. jT(pTa) “scaling violation”, kT evolution with pTt etc.)  Explore the direct photon associated spectra to measure “directly” the fragmentation function D(z). In ppg029 we have shown that D(z) cannot be extracted from the high-pT hadron associated distributions.  Apply the same technique on CuCu and AuAu.  Get at least preliminary before QM06 for run05 p+p and Cu+Cu, both low and top energy.

3. 3 Jan Rak6/14/2015 run05  0 reconstrunction

4. 4 Jan Rak6/14/2015 Run05 p+p 200 GeV/c All distributions generating using 800 run05 runs (full set, 7 10 8 gamma3 triggered events) - latest pro72 and pro73. Trigger efficiency: Event reduction factor:  E ,max > 2GeV = 30  E ,max > 3GeV = 250 ERT_gamma3 doesn’t seems to be very efficient ?

5. 5 Jan Rak6/14/2015 associated xE distributions run03 run05 With the run05 the pTt can go almost up to 20 GeV/c.

6. 6 Jan Rak6/14/2015 inverse xE slopes Exponential fit to x_E distributions show the same raising trend as run03 data

7. 7 Jan Rak6/14/2015 jT at “low” pTa however

8. 8 Jan Rak6/14/2015 High 3<pTa<6 GeV/c ?  j 2 T  =650  24 MeV/c  j 2 T  =607  5 MeV/c There is an apparent increase of jT when highe associated pTa bin is used. We are studying this in pythia.

9. 9 Jan Rak6/14/2015 Pythia simulations In order to develop an analysis of direct gamma associated spectra we studied a bit a pythia simulation. Typically we used following setting: First the jT as a function of pTt for various pTa bins was studied:

10. 10 Jan Rak6/14/2015 Pythia and CCOR Near angle peak, width and, seems to be closer to CCOR data for higher pTa, as we see in run05 data set. If it is a scale evolution of PDF - I do not know. Further study in progress…

11. 11 Jan Rak6/14/2015 Direct gamma Trigger With MSEL=10 one can select the direct photon production. Photon associated spectra are still smeared by kT effect. In the ideal case, when we can extract the direct photon from the pythia record, the associated slopes starts to be flat with pTt. pythia Data - note different scale

12. 12 Jan Rak6/14/2015 uncorrected kT Published ppg029 Run05 shows clearly a saturation - still under development. I am not showing the ppg029-like correction yet (eq. 49 published version). We are still exploring the how to constrain D(z) by use of gamma-charged correlations.

13. 13 Jan Rak6/14/2015 run05 width and pout

14. 14 Jan Rak6/14/2015

15. 15 Jan Rak6/14/2015

16. 16 Jan Rak6/14/2015 Summury Two interesting effect seen in run05  with higher associated pTa we get slightly larger jT – more close to older and STAR and CCOR measurement. This could not be seen in run03 – low stat.  Uncorrected kT reveals more clearly a saturation at high pTt We want to explore still a little bit the evolution of kT and jT with pTa. Above mentioned effect but also and fluctuations mentioned in ppg029, know it is possible to shrink pTa. Bonus: we switched the gears from angular width to p_out. Next time, we would like to preset a CuCu comparison