Future Plans for PHENIX

1. Future Plans for PHENIX Joe Seele (RIKEN/BNL Research Center) for the PHENIX Collaboration HEP2012

2. RHIC

3. Multifaceted Physics of PHENIX • Heavy Ion Program • Study medium properties • Search for the QCD critical point Cold Nuclear Matter Program • Study low-x properties of nuclear state, initial conditions, search for CGC Polarized p+p program • Study proton intrinsic properties • Study spin dependent strong interactions J. Seele - RBRC

4. PHENIX 2 central arms (|η|<0.35) electrons, photons, hadrons • charmonium J/, ’ -> e+e- • vector mesonr, w,  -> e+e- • high pTpo, p+, p- • direct photons • open charm, beauty (D,Be) • hadron physics 2 muon arms (1.2<|η|<2.4) • “onium” J/, ’,  -> m+m- • open charm, beauty (D,Bm) • W -> u J. Seele - RBRC

5. Near term upgrades (some completed, some not) J. Seele - RBRC

6. Heavy Flavour in HI/CNM Collisions • Heavy flavour measurements are essential to our understanding of quark energy loss and interactions in the QGP medium • With the “current” capabilities of PHENIX, measuring open heavy flavour channels is difficult -> add the ability to tag via a displaced vertex • Not only will this make new measurements possible, but it will reduce systematic uncertainties in some of our cornerstone measurements J. Seele - RBRC

7. Overview of Vertex Detector • Fine granularity, low occupancy • 50mm×450mm pixel sensor at inner 2 layers. • Unique strip sensor • 80mm×1000mm pixel pitch • Large acceptance |h|<1.2, almost 2p in f plane This detector is installed now and first measurements will be out soon! J. Seele - RBRC

8. Overview of Forward Vertex Det. • Two Arms, Four tracking stations with full azimuthal coverage • 75 m pitch strips in radial direction, 3.75° staggered phi strips • Radiation length < 2.4%/wedge to minimize multiple scattering This detector is being installed as we speak J. Seele - RBRC

9. Probing the Sea through Ws • Detect Ws through u+ andu- decay channels • V-A coupling leads to perfect spin separation • Neutrino helicity gives preferred direction in decay J. Seele - RBRC

10. A new high-p muon trigger • The muon rate at PHENIX is too high with the original muon triggering system (Muon Identifier gives p > 2 GeV/c trigger) • A new trigger based on Muon Tracker hit pattern recognition was built which allows for efficient triggering on muons with p > 7 GeV/c Old trigger New trigger J. Seele - RBRC

11. Far(ther) term upgrade(s) J. Seele - RBRC

12. Introducing sPHENIX Forward rapidity for Spin and Cold Nuclear Matter Physics Central rapidity for Heavy Ion Physics J. Seele - RBRC

13. HI Physics with sPHENIX The first part of the proposal will focus on these measurements as part of a DOE MIE J. Seele - RBRC

14. An old problem in Transverse Spin Large, forward ANs in hadron production in p+p (p+A) have been measured since the mid 70’s The asymmetries persist from low CM energies to high CM energies. A simple (collinear) pQCD calculation tells us that an AN can exist, but that it should scale like J. Seele (RBRC)

15. Spin Physics at sPHENIX - I With a good enough detector, we can unambiguously separate all these pieces Initial State Piece Jets with identified hadrons (measure AN for jets) Do jets from certain quarks prefer to go left or right? Final State Piece Left-right asymmetry of identified particle inside a jet Do certain hadrons fragment from certain quarks to the left or right of the jet axis? π0 π0 J. Seele (RBRC)

16. Spin Physics at sPHENIX - II There is a prediction that the Sivers function measured in DY should be opposite that measured in SIDIS. (Sivers)SIDIS = -(Sivers)DY DY is a very clean process. The measured asymmetry is directly related to the Sivers function as there is no uncertainty/smearing due to fragmentation. BUT, all the interesting asymmetry is at large rapidity J. Seele (RBRC)

17. CNM Physics with sPHENIX For CNM physics measurements of jets and DY at forward rapidity (1 < η < 4) can contribute significantly to our understanding mainly by Characterizing the initial state of nuclei which is a dominant systematic uncertainty that still plagues our understanding (forward jet-jet correlations) Understanding scattering and hadron formation in the cold nuclear environment (DY, J/Psi, etc) J. Seele - RBRC

18. Conclusions • Since its inception, PHENIX has been an ever evolving detector, and it continues to be with a variety of upgrades • The near term upgrades will provide exciting, unique physics capabilities for the next few years • In the far term, an ambitious suite of upgrades and new detectors is being pursued to allow for a broad spectrum of measurements • Also exploring the possibility of sPHENIX -> ePHENIX in the EIC (eRHIC) era • Stay tuned for the proposals and sensitivity plots and if you’re interested in collaborating let us know! J. Seele - RBRC

19. Backup Slides J. Seele -RBRC

20. A new high-p muon trigger • The muon rate at PHENIX is too high with the original muon triggering system (Muon Identifier gives p > 2 GeV/c trigger) • A new trigger based on Muon Tracker hit pattern recognition was built which allows for efficient triggering on muons with p > 7 GeV/c • The readout of the Muon Tracker is also quite slow (~7 bunch crossings) -> A new fast detector (based on resistive plates) was needed to properly identify the bunch crossing Old trigger New trigger J. Seele - RBRC

21. Extended Muon Piston Calorimeter • A highly segmented Si-W preshower upgrade to our existing MPCs which sit at 3.1 < |η|< 3.8 to distinguish between γ’s and π0’s • Measurements in d+Au should provide constrains on the low-x region of the nuclear parton distribution functions • The high segmentation will also allow for a crude jet-axis measurement giving access to the Collins and transversity distributions 21 J. Seele - RBRC

22. Spin Physics with sPHENIX • Make measurements to elucidate the source of the large forward analyzing powers that have been seen in polarized p+p collisions for decades. • DY measurement at forward rapidity to confirm sign flip of the Sivers function (as compared to the Sivers function measured in DIS) • Separate AN into initial state and final state effects to measure Sivers, Collins, and Transversity which are some of the possible spin-momentum correlations that can lead to the large ANs J. Seele - RBRC

23. Muon Arms Upgrades RPC3 • 2 dedicated trigger Resistive Plate Chambers (RPC) stations to identify the bunch crossing • 1 degree pitch in phi • New MuTr front end electronics give a fast, high momentum trigger RPC1 r=3.40m MuTr J. Seele - RBRC

24. Jets in HI Collisions The first part of the upgrade will be concerned with upgrading the central barrel to do jet measurements in the HI system J. Seele -RBRC

25. Towards ePHENIX In our efforts to pursue a significantly upgraded detector, we were charged with J. Seele -RBRC

26. Muon Arms New Trigger Upgrade Run11 500 GeV Projection σtot=60mb L=1.5x1032cm-2s-1 Rate 9 MHz BBCMuID Rejection Power RP~100 Trigger Upgrade RP ~ 45 90 kHz W RPtot ~ 4500 2 kHz PHENIX Band Width for Muon Required Rejection Power MuID Trigger High Rejection Power High Efficiency 26 J. Seele -RBRC

27. W->u in the Muon Arms New Trigger Upgrade • Muon Tracking Chambers • 3 stations of Cathode strip chambers • Each station has multiple planes for redundancy • Slow read out -> No trigger • Muon Identifier • 5 layers of Iarocci tubes in x and y • 80 cm of steel plate absorber (total) • Provides trigger p > 2 GeV W MuID Trigger J. Seele -RBRC

28. Heavy Flavor Measurements in HI • Precision Heavy Flavor Measurements via direct (e.g. DK) and indirect (e.g. Dl) measurements to distinguish different energy loss mechanisms in the plasma-->better determination of plasma properties • Separation of D and B measurements • Complete set of -onium measurements to understand Debye screening contributions from the plasma • Removal of di-lepton combinatorial background allows better open heavy flavor measurements, Drell-Yan becomes possible • Forward and Central rapidity measurements of open and closed heavy flavor to understand cold-nuclear matter effects and how they extrapolate to heavy-ion collisions J. Seele -RBRC

29. For the uninitiated… AN (analyzing power) is a left-right (about the spin) asymmetry in particle production Occurs in processes where one beam is transversely polarized and the other is unpolarized π0 π0 Spin is transverse to the beam momentum J. Seele (RBRC)

30. An old problem in Transverse Spin Large, forward ANs in hadron production in p+p (p+A) have been measured since the mid 70’s The asymmetries persist from low CM energies to high CM energies. A simple (collinear) pQCD calculation tells us that an AN can exist, but that it should scale like J. Seele (RBRC)

31. Much Theoretical Progress Since the mid to late 90’s new extended factorization schemes (TMD and Twist-3) have provided a new mechanism to generate single spin asymmetries in these collisions. Initial-state (Sivers-type) spin-momentum correlations – Considers intrinsic transverse momentum in the nucleon and initial-state interactions Final-state (Collins-type) spin-momentum correlations – Considers transverse momentum inside a jet and final-state interactions Other Higher Order Correlations AN ~ (Initial State Piece) + (Final State Piece) + (h.o.t.) J. Seele (RBRC)

32. Measuring these “pieces” With a good enough detector, we can unambiguously separate all these pieces Initial State Piece Jets with identified hadrons (measure AN for jets) Do jets from certain quarks prefer to go left or right? Final State Piece Left-right asymmetry of identified particle inside a jet Do certain hadrons fragment from certain quarks to the left or right of the jet axis? π0 π0 J. Seele (RBRC)

33. Interpreting these “pieces” This is a rapidly changing field and over the past few years there has been a huge amount of progress (it is really reshaping our understanding of pQCD and factorization). In one of the frameworks (TMD) the two pieces can be interpreted as The typical fragmentation function (Initial State Piece) ~ A Sivers function The Collins fragmentation function (Final State Piece) ~ A quark transversity distribution J. Seele (RBRC)

34. Are these functions universal? There is a prediction that the Sivers function measured in DY should be opposite that measured in SIDIS. (Sivers)SIDIS = -(Sivers)DY DY is a very clean process. The AN is directly related to the Sivers function as there is no uncertainty/smearing due to fragmentation. BUT, all the interesting asymmetry is at large rapidity J. Seele (RBRC)

35. MuTrg Performance J. Seele -RBRC