Forward Silicon Vertex Tracking in PHENIX

1. Forward Silicon Vertex Trackingin PHENIX Mike LeitchLANL Medium Energy Nuclear Physics Outline: What can a forward tracker do? Physics Program available with FVTX What is LANL’s role? Status

2. y = 1.2 y = 2.4 What can a forward tracker do? • Silicon Vertex Tracker for Forward Rapidity: • 4 layers of silicon accurately measuring vertex displacement, track trajectory at forward rapidity • Greatly enhances physics reach of PHENIX Muon System • Complements Barrel Tracker which will cover central rapidity Typical decay distances: D ~ 500 μm B ~ 1,300 μm Resolution ZVTX ~ 170 μm

3. Note: Prompt J/ys scaled down by 100 First Explicit Beauty Measurement Requires FVTX • Physics Motivation: • Open beauty measurement needed to separate charm and beauty components from single lepton measurements • Only explicit measurement of open beauty • Relatively free of background because prompt AND displaced B-decay vertex can be reconstructed • Additionally, c and b may be separated by different lifetimes of D, B (cm)

4. Simulation Simulation Real Data m from D and B Physics Program Available with FVTX • New Measurements become Feasible with Muon arms and Improve All Existing Muon Measurements • Allows direct measurement of beauty via B  J/ • Open Heavy Flavor can be extracted with precision from single muon background • W from single muons can be extracted to lower pT, background reduction • Drell-Yan measurements become feasible with separation from heavy-flavor

5. Spin Physics Measurements with the FVTX • Open heavy flavor  gluon polarization. Precision measurement only possible with large reduction of backgrounds • W  sea quark polarization. Broader kinematic range and background reduction with addition of FVTX • Drell-Yan valence and sea quark polarization. Extraction of Drell-Yan continuum from open heavy flavor and combinatorial background only feasible with FVTX • Entire muon arm spin program is broadened and/or improved with addition of FVTX

6. Cold Nuclear Matter Measurements with the FVTX • Only way to directly measure beauty production, via BJ/ • Entire spectrum of –onia measurements can be explored only with FVTX • Likely only way to access ’ with precision • J/ and  measurements with improved resolution and background rejection provided by FVTX • Combination of all measurements necessary to untangle various cold nuclear matter effects • Open heavy flavor measurements can only be made with addition of FVTX which can significantly reduce backgrounds • Also critical in combination with above to untangle CNM effects • Drell-Yan measurements to help understand energy loss • Entire muon arm CNM program is broadened and/or improved with addition of FVTX

7. LANL’s Role • FVTX • Project manager - Melynda Brooks • Successfully passed BNL review and submitted to DOE for FY08 funding • LDRD • Obtained $1.25M/year grant from LANL to put in small acceptance vertex tracker, and work with T-division on expanding theory • Pat McGaughey PI, Emil Mottola (T-16) co-PI • Will share readout technology and analysis techniques with FVTX so will advance FVTX in addition to getting early physics • VTX • Major responsibility in mechanical structure

8. Status • FVTX • Proposed construction start in FY08 • Calculated installation complete in FY10 • Cost of $4.5M • LDRD • Grant covering FY06 thru FY08 • Expected installation before FY09 • Precise heavy flavor measurement via single muons will be obtained • Work on technical issues already in progress

9. Summary • Addition of FVTX/LDRD silicon trackers will greaty enhance the spin physics and cold-nuclear physics program attainable with the PHENIX Muon Arms • LANL has lead the effort on the FVTX proposal, successfully defended this to BNL, and external review committees and sent proposal to DOE. • LANL has also brought critical funding through our LDRD grant which should provide much of the R+D needed also for the FVTX project • We look forward to the coming physics program with this critical detector addition