1. 1 DOE Office Of Nuclear Physics Supplemental Request For the Purdue Relativistic Heavy Ion Group Grant DE- FG02-88ER404 The Experimental Study Of The Phase Structure Of Strongly Interacting Matter Project Period (1/1/2007) to (12/31/2007) March 30, 2007

2. 2 FacultyR. ScharenbergProf. of Physics A. HirschProf. of Physics F. WangAssoc. Prof. of Physics B. SrivastavaAsst. Research Professor New HireW. XieAsst. Prof. of Physics StaffB. StringfellowResearch Scientist Post Doc.P. Netrakanti Grad.StudentJ. Ulery4th year research T. Tarnowsky3rd year research M. Skoby2nd year research Purdue Personnel

3. 3 PURDUE’S INTEREST IN THE PHASE STRUCTURE OF HADRONIC MATTER The Purdue High Energy Nuclear Physics Group has been a pioneer in the study of the phase structure of hadronic matter. We have found compelling evidence for a nuclear Liquid-Gas critical phase thermal transition at an excitation energy of 5 MeV/nucleon using internal gas jet targets at the Fermi National Accelerator and at the Brookhaven National laboratory (BNL). At the Lawrence Berkeley Laboratory a complete reconstruction of the nuclear multifragmentation of 1 GeV per nucleon Au on C nuclei determined critical indices and the critical scaling function. At (FNAL) we found clear evidence for the Quark-Gluon to Hadron transition at a transition energy density of 1.1 GeV/fm 3 from p-pbar collisions at 1.8 TeV. We also found large long range forward-backward multiplicity correlations indicating the presence of multiple parton-parton interactions in these events.

4. 4 REDIRECTION OF ~50% OF STAR RESEARCH TO EMCAL RESEARCH AT ALICE The group presently has major hardware and software responsibilities in STAR which have been critical to the success of the STAR program. We want to redirect some of our efforts from RHIC to the LHC 1.Blair Stringfellow is the TPC subsystem manager and has provided critical service work and supervision over TPC maintenance and data taking. Stringfellow will retire in 2008 and Purdue will phase out of this responsibility in 2008. 2. Srivastava, Tarnowsky and Skoby will phase out their FTPC calibration, software, and operational maintenance in 2008. We will end this service responsibility by 2009.

5. 5 REDIRECTION OF ~50% OF STAR RESEARCH TO EMCAL RESEARCH AT ALICE 3. Hirsch, Wang and Xie will work at STAR. We expect that Purdue will continue to play a very active role in the STAR II program, for example in the construction of upgrades for the STAR detector. 4. Srivastava and Scharenberg are interested in the EMCAL initiative at LHC. We are committed to contributing to detector support and simulation-analysis efforts for EMCAL. We are interested in the analysis of Long Range Forward-Backward multiplicity correlations in Pb-Pb collisions at 5.5 TeV. 5. To summarize: It is proposed that two faculty, one postdoctoral research scientist and two PhD. students will work full time on the ALICE EMCAL program.

6. 6 RESEARCH USING THE EMCAL DETECTOR The Purdue interest in physics using the electromagnetic calorimeter (EMCAL) is in studying jet-jet and  -jet tomography of Pb-Pb collisions at  s = 5.5 TeV. The new EMCAL detector will provide the essential trigger capability for these 2 to 2 reactions over a wide range of Q 2 corresponding to jet energies < 200 GeV. An unambiguous signal for deconfinement is the determination of the number of the degrees of freedom (DOF). At the critical temperature lattice gauge numerical simulations predict DOF  20. At temperatures well above the critical temperature lattice-gauge simulations predict that the DOF  40. The cleanest deconfinement signal is the number of degrees of freedom (DOF) g( ) at the earliest time after the Pb-Pb collision. We can follow the suggestion by B. Muller and K. Rajagopal entitled “ From Entropy and Jet Quenching to Deconfinement ”.

7. 7 RESEARCH USING THE EMCAL DETECTOR For a thermalized system this can be done by measuring the ratio of the “ initial ” entropy density to the initial energy density ie. eliminating the temperature. For entropy density s and energy density  the ratio s 4 /  3  1.0 g ( ) is independent of the temperature. An analysis based on the inferred chemical freezeout multiplicities of hadrons has the potential to extract the entropy at chemical freezeout directly. Assuming an isentropic expansion, the initial entropy density could be estimated The initial energy density determination requires the jet quenching studies using the EMCAL trigger signal. A complete theoretical discussion of this approach can be found in their paper. B. Mueller, K. Rajagopal Eur. Phy. J. C. 43, 15-21 (2005)

8. 8 LONG RANGE FORWARD-BACKWARD MULTIPLICITY CORRELATIONS Recently we have discovered very large long range forward- backward multiplicity correlations (LRC) in central Au-Au collisions at 200 GeV. Both the dual parton model (DPM) and color glass condensate considerations (CDC) argue that these correlations are due to multiple parton-parton interactions ie. indicating the presence of dense quark-gluon matter. This suggests that there is a central core surrounded by a halo of hadrons. It is very important to explore this lateral structure using the LRC signal in Pb-Pb collisions and correlate it with the jet quenching energy density and jet fragmentation function measurements.

9. 9 LRC exists only if: F-B Multiplicity Correlations Predicted in context of DPM. Test of multiple [partonic] scattering. Linear expression relating N b, N f found in hadron-hadron experiments (ex. UA5), “b” is correlation strength. –Function of √s and A. –Coefficient can be expressed as,

10. 10 Fluctuation in # of inelastic collisions Measurement of Long-Range Multiplicity Correlations A gap about midrapidity will reduce the effect of short- range correlations. DPM assumes short-range correlations confined to individual strings. Long-range correlations are due to superposition of strings.

11. 11 Long Range Short + Long Range Low Energy Strings High Energy Forward n f Backward n b η2η2 η Rapidity Gap η1η1 0 - η 1 - η 2 Rapidity interval

12. 12 Centrality Dependence of b coefficient vs rapidity gap STAR Preliminary

13. 13 p-p at 200 GeV b coefficient versus rapidity gap STAR Preliminary

14. 14 Centrality dependence of b coefficient for Au-Au (200 GeV) STAR Preliminary

15. 15 Comparison of Data with HIJING and PSM

16. 16 FB Correlation Strength Pt cut studies Pt > 0.15 GeV 1.0 > Pt > 0.15 0.8 > Pt > 0.15 0.6 > Pt > 0.15 STAR Preliminary

17. 17 FB Correlation Strength QM 2006 Long range correlation After subtracting the short range using pp data

18. 18 PURDUE DELIVERABLES 1 FABRICATE/ TEST LED SYSTEM COMPONETS 2007-2010 2007 - Hire and train 2 undergraduate students to fabricate (cut and polish) ~ 3000 fibers - Begin assembly of test boards 2008 - Install quality testing system for fibers - Quality testing system approved - Cut and polish ~3000 additional fibers - Finish assembling test boards (~1000 total)

19. 19 PURDUE EMCAL DELIVERABLES 2 FABRICATE/TEST LED SYSTEM COMPONENTS 2009 - Hire and train 2 undergraduate students - Cut and polish 3000 fibers - Test ~6000 fibers - Deliver batch of ~ 6000 tested fibers 2010 - Cut and polish ~3000 fibers (12,000 total) - Finish testing of all fibers - Deliver final 6,000 tested fibers

20. 20 PURDUE INSTITUTIONAL PLAN MILESTONES 1 2007 - p-p multiplicity distributions for 3< dNc/d  <70 - Emcal detector simulations. - Finish long range forward-backward multiplicity studies at STAR. 2008 - Emcal calibration measurements - p-p long range forward-backward correlations and Handbury-Brown Twiss (HBT) physics analyses as a function of dNc/d .

21. 21 PURDUE INSTiTUTIONAL PLAN MILESTONES 2 2009 - Emcal calibration measurements - p-p  -jet and jet-jet reference analyses - finish HBT physics analysis. 2010 - Online Data acquasition with Emcal and other ALICE subsystems - LRC analysis of Pb-Pb data

22. 22 PURDUE INSTITUTIONAL PLAN MILESTONES 3 2011 - Compare LRC and jet quenching and determine initial energy density at t o = 1fm/c. - Determine freezeout entropy density for central Pb-Pb collisions. 2012 - Measure centrality dependence of LRC in Pb-Pb collisions - Determine quantitative quark-gluon matter fraction using LRC in both peripheral and central Pb-Pb collisions

23. 23 Site Differential Estimates Based on 2006 travel Domestic TravelYearForeign Travel 29 trips20064 trips 25 trips20078 trips 21 trips200812 trips Cost differential between the average domestic trip and the average foreign trip ~ $ 2000. Estimated site differential costs for: 2007 2008 $8000 $16,000 Unexpended funds for 2007 are expected to be: $ 0.00.

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