1. 4.5 GeV Au+Au Analysis Plan
Why study fixed-target Au+Au collsions at 4.5 GeV?
QGP “signatures” have been seen all the way down to 7.7 GeV, although most “disappear” as we reach the lowest BES energy, we do not have a clean “control” energy that can be clearly stated as being confidently pure hadron gas.
The NA49 collaboration pointed to 7.7 GeV as the onset of deconfinement. Again we would like to student energies both above and below this onset energy.
There was a robust experimental program with Au+Au collisions at the AGS. There are many studies to which we can compare.
The goal of these analyses will be to repeat the students of the previous AGS experiments to verify that we can make the same measurements.
Further studies which use newer analysis techniques and draw deeper conclusions would likely need to be separate papers.

2. Background – What has been done previously
AGS AGeV/c Gold beams in 1993 (√sNN = 4.9)
AGS 2, 4, 6, and 8 AGeV Gold beams in 1994 and 1995 (√sNN = 2.7, 3.3, 3.8, 4.3)
Experiments:
E866/E917 (Spectrometer) [Previously E802/E859]
E891 (MPS TPC) [Previously E810]
E877 (Forward Calorimeter) [Previously E814]
E895 (EOS TPC) [Only 2, 4, 6, and 8 AGeV]

3. Published Results By Topic
Spectra
Pions: E895, E877, E917
Kaons: E9866/E917
Protons: E895, E877, E802, E917
Anti-protons: E802
Light nuclei: E814/E877, E802
Strangeness
K0s: none
Lambda: E877
Anti-Lambda: E917
Cascade: E895 (at 6 AGeV)
Phi: E917
Directed Flow:
K0s: E895
Protons: E895, E802, E877
Anti-protons: E877
Lambdas: E895, E877
Light nuclei: E802
Elliptic Flow:
Protons: E895
HBT:
Pions: E895, E877, E802
Protons: E877

4. Spectra

5. Spectra Task List
p- : Need embedding, energy loss correction, background and feeddown correction
p+ : Need TOF, emb.,ELC., BFC.
K+/- : Need TOF, emb., ELC., BFC.
p: Need TOF, emb., ELC., BFC., need knock-out proton correction
p¯: Need TOF, emb., ELC., BFC.
d, t, h: Need emb., ELC., need knock-put correction, need absorption correction
Anti-light nuclei: Not worth pursuing. Not enough statistics.

6. Spectra -- pions
E895_PRC68(2003)054905

7. Spectra -- pions
E877_PRC62(2000)024901

8. Spectra -- pions
E802_PRC57(1998)R466

9. Spectra -- pions
E917_PLB476(2000)1

10. Spectra - Kaons
E866_PLB490(2000)53

11. Spectra -- Kaons
E917_PLB476(2000)1

12. Spectra - Protons
E917 PRL86(2001)1970

13. Spectra -- protons
E802_PRC57(1998)R466

14. Spectra -- protons
E802_PRC60(1999)064901

15. Spectra -- protons
E895_PRL88(2002)102301

16. Spectra -- protons
E877_PRC56(1997)3254

17. Spectra -- Protons
E877_PRC62(2000)024901

18. Spectra – Anti-protons and anti-Lambdas
E917_PRL(2001)242301

19. Spectra – anti-protons
E802_PRL81(1998)2650

20. Spectra -- deuterons
E814_PRC61(2000)044906

21. Spectra -- deuterons
E802_PRC60(1990)064901

22. Spectra – tritons and helions
E814_PRC61(2000)044906

23. Spectra – d, t, h
E814_PRC50(1994)1077

24. Strangeness

25. Strangeness - Lambdas
E877_PRC63(2001)014902

26. Strangeness – Phi meson
E917_PRC69(2004)054901

27. Strangeness – Lambdas and Cascades
E895_PRL91(2003)202301

28. Directed Flow

29. Directed Flow -- Protons
E895_PRL84(2000)5488

30. Directed Flow -- Lambdas
E895_PRL86(2001)2533

31. Directed Flow – pions and nucleons
E877_PRC55(1997)1420

32. Directed Flow – protons and pions
E877_PRC56(1997)3254

33. Directed Flow – Protons and anti-protons
E877_PLB485(2000)319

34. Directed Flow -- Kaons
E895_PRL85(2000)940

35. Directed Flow – Lambdas and Protons
E877_PRC63(2001)014902

36. Elliptic Flow

37. Elliptic Flow -- protons
E877_PRC56(1997)3254

38. Elliptic Flow -- protons
E895_PRL83(1999)1295

39. Elliptic Flow --- protons
E895_PRC66(2002)021901

40. HBT

41. HBT -- pions
E895_PRL84(2000)2798

42. HBT -- pions
E802_PRC66(2002)054096

43. HBT -- pions
E877_PRL78(1997)2916

44. HBT – asHBT -- Pions
E895_PLB496(2000)1

45. HBT -- protons
E814_PRC60(1999)054905

46. OK… What next… We really ought to be preparing the Analysis Note as we are going along. Please refer to the Fixed Target Coulomb Paper analysis note for reference:
I will follow the layout of that analysis note and figure out where we are and what we need to be doing next.
Motivation:
Refer back to the first slide of this .pptx.

48. 2. Fixed Target Basics:
OK… here we just want some pretty picture of fxt Au+Au events
3.9 GeV Au+Au 2014
4.5 GeV Au+Au

51. Out-of-time pile-up of gold nuclei with the beam pipe

53. PseudoRapidity Considerations
Internal Fixed Target
PseudoRapidity Considerations
eTOF:
Z = -270 cm
Rmin = 100 cm
Rmax = 192 cm LT
η=0 cm
DZ = 480 cm
Barrel TOF
η=1.49
210
190
Outer Sectors
32 pad rows
Inner Sectors
40 pads rows
Outer Sectors
32 pad rows
Inner Sectors
40 pads rows
η=1.66
eTOF
eTOF lower eta limit
126
120
η=2.27
eTOF upper eta limit
η=2.6 60
Target located at Z = +210 cm
-270
-200
200

54. 3. Data Sets (4.5 GeV Au+Au): May 18th, 2015 08:00 to 12:30
The bulk of the time during the test run was spent carefully lowering the beam elevation to graze the target and tuning up the trigger. During the final half hour, we asked for a 6 bunch fill and tried to tune the beam to fill the DAQ bandwidth.
Run Number
Bunches
TOFmult
Triggers
Events Vz =VT 1
130
89294
TBD 50
116629
119238 6
160
603721
414977

56. Run 37
Run 33
Run 36
Run 38
FXT trigID= 1
laser trigger = 62 (Run 037 only)
Run 34
The TOFmult cut for run 35 was 200

58. 4. Event Selection: 4.5 GeV Au+Au 4.5 GeV Au+Au
Trigger == no selection
210 < Vz < 212
-1.5 < Vx < 1.0
-2.5 < Vy < -1.0
TofMatch > 1
Saturated DAQ Bandwidth with 6 bunches.
% of trigger were Au+Au events still TBD
4.5 GeV Au+Au
4.5 GeV Au+Au

59. Out of time pile-up from the 6 bunch runs

62. Usman’s Vertex distribution

63. Before Vertex Cuts

64. 5. Centrality Determination:
This has been done without cutting out the out-of-time triggers discovered by Lukasz. When making this centrality selection you should cut on # of primary tracks that pass track cuts (nHitsFit/nHitsPoss > 0.52 and nHitsdEdx > 0): Top 5%: >= 153 Top 10%: >= 121 Top 15%: >= 97 Top 20%: >= 77 Top 25%: >= 61 Top 30%: >= 48
Estimate of irreducible pile-up

67. Even More Confused by Usman’s analysis

68. 6. Track Selection: Track quality requirements: •nHitsdEdx> 0
•nHitsFit/nHitsPoss>= 0.52

69. 7. Acceptance in FXT mode:
ymid = 1.52

79. TOF Efficiency

80. TOF Incidence Angle on Slat – By Slat Row

81. TOF Local y and z for Collider Geometry

83. Spectra

84. 8. PID Plots:
p, d, t,
K+, p+,
p, d, t,
K+, p+,
K-, p-

87. Issue was observed in November… see next slide… still not resolved…

89. 9. dE/dx Fits:

90. 10. Efficiency Corrections:

91. 11. Energy Loss Corrections

92. 12. Background and Feed down Corrections

93. 13. Invariant Transverse Mass Spectra

99. 14. Rapidity Density Plots:

100. 15. Slope Parameter Plots:

101. Strangeness

111. STAR Preliminary
4.5 GeV Au+Au

117. Directed Flow

124. Elliptic Flow

128. HBT

134. Fluctuations