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.

Background – What has been done previously AGS 11.7 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]

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

Spectra

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.

Spectra -- pions E895_PRC68(2003)054905

Spectra -- pions E877_PRC62(2000)024901

Spectra -- pions E802_PRC57(1998)R466

Spectra -- pions E917_PLB476(2000)1

Spectra - Kaons E866_PLB490(2000)53

Spectra -- Kaons E917_PLB476(2000)1

Spectra - Protons E917 PRL86(2001)1970

Spectra -- protons E802_PRC57(1998)R466

Spectra -- protons E802_PRC60(1999)064901

Spectra -- protons E895_PRL88(2002)102301

Spectra -- protons E877_PRC56(1997)3254

Spectra -- Protons E877_PRC62(2000)024901

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

Spectra – anti-protons E802_PRL81(1998)2650

Spectra -- deuterons E814_PRC61(2000)044906

Spectra -- deuterons E802_PRC60(1990)064901

Spectra – tritons and helions E814_PRC61(2000)044906

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

Strangeness

Strangeness - Lambdas E877_PRC63(2001)014902

Strangeness – Phi meson E917_PRC69(2004)054901

Strangeness – Lambdas and Cascades E895_PRL91(2003)202301

Directed Flow

Directed Flow -- Protons E895_PRL84(2000)5488

Directed Flow -- Lambdas E895_PRL86(2001)2533

Directed Flow – pions and nucleons E877_PRC55(1997)1420

Directed Flow – protons and pions E877_PRC56(1997)3254

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

Directed Flow -- Kaons E895_PRL85(2000)940

Directed Flow – Lambdas and Protons E877_PRC63(2001)014902

Elliptic Flow

Elliptic Flow -- protons E877_PRC56(1997)3254

Elliptic Flow -- protons E895_PRL83(1999)1295

Elliptic Flow --- protons E895_PRC66(2002)021901

HBT

HBT -- pions E895_PRL84(2000)2798

HBT -- pions E802_PRC66(2002)054096

HBT -- pions E877_PRL78(1997)2916

HBT – asHBT -- Pions E895_PLB496(2000)1

HBT -- protons E814_PRC60(1999)054905

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: http://nuclear.ucdavis.edu/~star/protected/FixedTargetPaper/analysisdetails.php 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.

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 2015

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

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

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 16140033 1 130 89294 TBD 16140034 50 116629 16140036 119238 16140037 6 160 603721 16140038 414977

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

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

Out of time pile-up from the 6 bunch runs

Usman’s Vertex distribution

Before Vertex Cuts

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

Even More Confused by Usman’s analysis

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

7. Acceptance in FXT mode: ymid = 1.52

TOF Efficiency

TOF Incidence Angle on Slat – By Slat Row

TOF Local y and z for Collider Geometry

Spectra

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

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

9. dE/dx Fits:

10. Efficiency Corrections:

11. Energy Loss Corrections

12. Background and Feed down Corrections

13. Invariant Transverse Mass Spectra

14. Rapidity Density Plots:

15. Slope Parameter Plots:

Strangeness

STAR Preliminary 4.5 GeV Au+Au

Directed Flow

Elliptic Flow

HBT

Fluctuations