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STAR MTD: Physics Motivation, R&D Results and Requirements

STAR MTD: Physics Motivation, R&D Results and Requirements. L ijuan Ruan for STAR-MTD group ( Brookhaven National Laboratory ). Outline: Physics motivation with the STAR-MTD Simulation and R&D results Trigger details for the full system Conclusions .

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STAR MTD: Physics Motivation, R&D Results and Requirements

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  1. STAR MTD: Physics Motivation, R&D Results and Requirements LijuanRuan for STAR-MTD group (Brookhaven National Laboratory) Outline: • Physics motivation with the STAR-MTD • Simulation and R&D results • Trigger details for the full system • Conclusions http://www.star.bnl.gov/~ruanlj/MTDreview2010/mtd.htm http://drupal.star.bnl.gov/STAR/system/files/MTD_proposal_v14.pdf MTD workshop at USTC, Lijuan Ruan (BNL)

  2. What Have We Learnt So Far at RHIC A hot, dense medium with partonic degrees of freedom created at RHIC: Jet quenching Baryon enhancement, number of constituent quark scaling in elliptic flow … Next: Is the system thermalized and how does the system thermalize? What are the properties of the strongly-coupled system? What is the phase structure of QCD matter? What exotic particles are produced at RHIC? What is the mechanism for partonic energy loss? Does QCD matter demonstrate novel symmetry properties? What is the nature of the initial state in nuclear collisions … MTD workshop at USTC, Lijuan Ruan (BNL)

  3. Muons: Penetrating Probes The initial temperature of sQGP; the mass origin of hadrons; color screening features of heavy quarkonia … MTD workshop at USTC, Lijuan Ruan (BNL)

  4. Charm Contribution to Di-lepton Spectrum PHENIX, PRC81,034911(2010) NA60, PRL96,162302(2006) • Charm contribution to di-lepton spectra is significant at low mass at RHIC. • Charm contribution to di-lepton spectra might be dominant in the intermediate mass region. Its correlation makes a big difference to access the thermal radiation contribution from QGP. MTD workshop at USTC, Lijuan Ruan (BNL)

  5. Cocktail Simulation in 200 GeV p+p at STAR STAR: π, KS, K*, , ρ PHENIX: η, ω, J/ Z. Tang et al., PRC 79,051901(R)(2009); M. Shao et al., J. Phys. G: Nucl. Part. Phys. 37 (2010) 085104 ccbar: star measured cross section as input; STAR Collaboration, PRL94(2005)062301 bbar/ccbar ratio from PYTHIA Particle spectra from data were fit with Tsallis function, and were used as an input to full GSTAR simulation to generate e+e- invariant mass cocktail. Same cuts were applied in simulation as in data. MTD workshop at USTC, Lijuan Ruan (BNL)

  6. STAR-MTD Physics Motivation • A large area of muon telescope detector • (MTD) at mid-rapidity, allows forthe • detection of • di-muon pairs from QGP thermal radiation,quarkonia, light vector mesons, possible correlations of quarksand gluons • as resonances in QGP, and Drell-Yan production • single muons from thesemi-leptonic decays of heavy flavor • hadrons • advantages over electrons: no  conversion, much less Dalitz decay contribution, less affected by radiative losses in the detector • materials, trigger capability in Au+Au • trigger capability for low to high pT J/ in central Au+Au collsions • excellent mass resolution, separate different upsilon states • e-muon correlation to distinguish heavy flavor production from initial lepton pair production MTD workshop at USTC, Lijuan Ruan (BNL)

  7. Concept of Design of the STAR-MTD A detectorwith long-MRPCs covers the whole iron bars and leave the gaps in- between uncovered. Acceptance: 45% at ||<0.5 118 modules, 1416 readout strips, 2832 readout channels Long-MRPC detector technology, HPTDC electronics (same as STAR-TOF) MTD workshop at USTC, Lijuan Ruan (BNL)

  8. Single Muon and J/ Efficiency G. Lin, Yale Univ. J/ efficiency • muon efficiency at |η|<0.5: 36%, pion efficiency: 0.5-1% at pT>2 GeV/c • muon-to-pion enhancement factor: 50-100 • muon-to-hadron enhancement factor: 100-1000 including track matching, tof and dE/dx • dimuon trigger enhancement factor from online trigger: 40-200 in central Au+Au collisions MTD workshop at USTC, Lijuan Ruan (BNL)

  9. Comments on Simulations MTD workshop at USTC, Lijuan Ruan (BNL)

  10. High Mass Di-muon Capabilities Quarkonium dissociation temperatures – Digal, Karsch, Satz Z. Xu, BNL LDRD 07-007; L. Ruan et al., Journal of Physics G: Nucl. Part. Phys. 36 (2009) 095001 • J/: S/B=6 in d+Au and S/B=2 in central Au+Au • With HFT, study BJ/ X; J/ using displaced vertices • Excellent mass resolution: separate different upsilon states • Heavy flavor collectivity and color • screening, quarkonia production • mechanisms: • J/ RAA and v2; upsilon RAA … MTD workshop at USTC, Lijuan Ruan (BNL)

  11. Future Measurement Projection J/ Υ J/ J/ RAA and v2; ΥRAA versus Npart… Z. Tang, USTC MTD workshop at USTC, Lijuan Ruan (BNL)

  12. Upsilon Statistics Using MTD at |y|<0.5 Delivered luminosity: 2013 projected; Sampled luminosity: from STAR operation performance Upsilon in 500 GeV p+p collisions can also be measured with good precision. MTD workshop at USTC, Lijuan Ruan (BNL)

  13. High luminosity for Υ & J/ from e+e- STAR high pT J/ MTD workshop at USTC, Lijuan Ruan (BNL)

  14. Compared to Υ e+e- with HFT Material budget with HFT similar to that at year 2004 With HFT, it’s hard to separate different upsilon states; e+e- channel samples collisions of |vz|<5 cm; can not sample full luminosity due to more material at |vz|>5 cm MTD workshop at USTC, Lijuan Ruan (BNL)

  15. Distinguish Heavy Flavor and Initial Lepton Pair Production: e-muon Correlation Z. Xu, BNL LDRD 07-007; L. Ruan et al., Journal of Physics G: Nucl. Part. Phys. 36 (2009) 095001 NA60, PRL100,022302(2008) e correlation simulation with Muon Telescope Detector at STAR from ccbar: S/B=2 (Meu>3 GeV/c2 and pT(e)<2 GeV/c) S/B=8 with electron pairing and tof association MTD: construction starts in FY2011; project completion in FY2014 R. Rapp, hep-ph/0010101 MTD workshop at USTC, Lijuan Ruan (BNL)

  16. The details for the R&D modules MTD workshop at USTC, Lijuan Ruan (BNL)

  17. The R&D Results for the MTD Long MRPC Technology with double-end readout HV: 6.3 KV gas mixture: 95% Freon + 5% isobutane time resolution: ~60 ps spatial resolution: ~1cm efficiency: >95% 950 mm 25 mm 256 mm Y. Sun et al., nucl-ex/0805.2459; NIMA 593, 430 (2008) MTD workshop at USTC, Lijuan Ruan (BNL)

  18. Fermi Lab Beam Test Results (T963 May 2-15 2007) Y. Sun et al., NIMA 593, 430 (2008) T963 spokesperson: Z. Xu HV: 6.3 KV gas mixture: 95% Freon + 5% isobutane time resolution: ~60-70 ps spatial resolution: ~0.6-1cm efficiency: >95% consistent with cosmic test results MTD workshop at USTC, Lijuan Ruan (BNL)

  19. Run 10 Performance: Time and Spatial Resolution L. Li, UT Austin pure muons average pT: ~6 GeV/c σ: 109 ps Cosmic ray trigger (Z. Xu) Total resolution: 109 ps Start resolution (2 TOF hits): 46 ps Multiple scattering: 25 ps MTD intrinsic resolution: 96 ps System spatial resolution: 2.5 cm, dominated by multiple scattering σ: 2.5 cm MTD workshop at USTC, Lijuan Ruan (BNL)

  20. Trigger Capability with MTD Acceptance RHIC II lumonisity in terms of collision rate: 40 k Hz; Au+Au projection: based on Run 10 prototype performance. 1 ns trigger window: 80 Hz for dimuon trigger Run10 Au+Au B. Huang, USTC MTD workshop at USTC, Lijuan Ruan (BNL)

  21. MTD Trigger System • The primary physics goal requires triggering on di-muon events sampling full luminosity. • To select muons and reject hadronic showers that punch through the magnet steel, a timing cut will be applied to the MTD signals. • Since the MTD pickup strips are ~90 cm in length and readout from both ends, the sum (E+W)/2 will be calculated in the trigger and compared to the collision time. • The average arrival time at MTD boxes in different eta region is different due to difference in path length. • The occupancy in the MTD is very low, only one east and one west signal is sent to trigger from the 60 strips of 5 MTD boxes in the same eta region at 5 nearby backlegs. This allows for a correction on the arrival time in the high eta region at trigger level. The correction could be larger than 1 ns in the highest eta region. MTD workshop at USTC, Lijuan Ruan (BNL)

  22. MTD Trigger System • Each 12 strip MRPC is readout by 4 NINO frontend ASICs on a MINO card. Each NINO reads out 6 east ends or 6 west ends. The NINO produces a logic output signal if any of the 6 inputs is above threshold. • The 10 NINO signals and the corresponding east/west signals are logically combined by the MTRG card and a single east and west signal is sent to trigger from 5 MTD boxes in the same eta range at the 5 nearby backlegs. • Each QT can produce 8 (E+W)/2 sums. 4 QT boards required in all. • The QT is currently in use for the STAR trigger system. MTD workshop at USTC, Lijuan Ruan (BNL)

  23. MTD System Requirement MTD requirements: • Time resolution less than 100 ps, spatial resolution ~ 1 cm. • The mechanics design must allow a convenient replacement of individual MTD box and access to the BEMC box. • The system must be able to operate in the fringe field from 0.5 Tesla STAR magnet field. • The system must operate at low noise rate. The total noise rate should be less than 0.5 M Hz, 1 Hz/cm2. • The system must be safe, meet all BNL safely requirements. • The system must not impair the performance of other STAR detectors. MTD workshop at USTC, Lijuan Ruan (BNL)

  24. Organization MTD group: • Brookhaven National Laboratory: L. Ruan, Z. Xu, K. Asselta, W. Christie, C. D’Agostino, J. Dunlop, J. Landgraf, T. Ljubicic, J. Scheblein, R. Soja, A.H. Tang, T. Ullrich • University of California, Berkeley: H.J. Crawford, J. Engelage • University of California, Davis: M. Calder′on de la Barca S′anchez, R. Reed, H.D. Liu • Rice University: J. Butterworth, G. Eppley, F. Geurts, W.J. Llope, D. McDonald, T. Nussbaum, J. Roberts, K. Xin, L. Bridges • University of Science & Technology of China: H.F. Chen, B.C. Huang, C. Li, M. Shao, Y.J. Sun, Z.B. Tang, X.L. Wang, Y.C. Xu, Z.P. Zhang, H. Zeng, Y. Zhou • Texas A&M University: Y. Mohammed, S. Mioduszewski • University of Texas, Austin: A. Davila, G.W. Hoffmann, L. Li, C. Markert, L. Ray, J. Schambach, D. Thein, M. Wada • Tsinghua University: J.P. Chen, K.J. Kang, Y.J. Li, Y. Wang, X.L. Zhu • Variable Energy Cyclotron Centre: Z. Ahammed, P.P. Bhaduri, S. Chattopadhyay, A.K. Dubey, M.R. Dutt-Mazumdar, P. Ghosh, S.A. Khan, S. Muhuri, B. Mohanty, T.K. Nayak, S. Pal, R. Singaraju, V. Singhal, P. Tribedy, Y.P. Viyogi MTD workshop at USTC, Lijuan Ruan (BNL)

  25. MTD Schedule Design Production Design Production Design Production Finish the project by Mar, 2014 and make 80% of the full system ready for year 2014 run MTD proposal submitted to BNL in Feb. 2010;STAR-MTD review held in Sep. 2010. The project approved in Mar. 2011. Now in the process of setting up charge numbers. MTD workshop at USTC, Lijuan Ruan (BNL)

  26. Summary • MTD will advance our knowledge of Quark Gluon Plasma: trigger capability for low to high pT J/ in central Au+Au collsions excellent mass resolution, separate different upsilon states e-muon correlation to distinguish heavy flavor production from initial lepton pair production different background contribution provides complementary measurements for dileptons • The prototype of MTD works at STAR from Run 7 to Run 10. Results published at L. Ruan et al., Journal of Physics G: Nucl. Part. Phys. 36 (2009) 095001; 0904.3774; Y. Sun et al., NIMA 593 (2008) 430. muon purity>80%; the primary muon over secondary muon ratio: good for quarkonium program the trigger capability with L0 and L2: promising for dimuon program: Upsilon, J/ elliptic flow v2 and RAA at high pT • The larger Run 11 modules with slightly wider readout strips show a comparable performance as the modules in Runs 7-10, based on cosmic ray tests at USTC and Tsinghua. MTD workshop at USTC, Lijuan Ruan (BNL)

  27. Backup MTD workshop at USTC, Lijuan Ruan (BNL)

  28. STAR-MTD in Year 2007 and 2008 • iron bars as hadron absorber • 403 cm away from TPC center, ||<0.25 MTD workshop at USTC, Lijuan Ruan (BNL)

  29. Performance of a Prototype at STAR • MTD hits: matched with real high pT tracks • z distribution has two components: narrow (muon) and broad (hadron) ones • spatial resolution (narrow Gaussian) is ~10 cm at pT>2 GeV • narrow to broad ratio is ~2; can be improved with dE/dx and tof cut • are the particles in the narrow Gaussian muons? MTD workshop at USTC, Lijuan Ruan (BNL)

  30. Runs 9-10 Prototype Issues from Runs 7-8: Time resolution for the full system: 300 ps Start resolution: 160 ps (start detector withtrigger readout) Multiple scattering: 70 ps Intrinsic MTD resolution: 200-300 ps Is this real?  install a prototype with TOF electronics in run9 Runs 9-10: 3 modules, one tray covered: 87(z)51() cm2 18 channels on each side 2 TINO,TDIG, TTRG boards, 1 TCPU board Both ends go to trigger QT MTD workshop at USTC, Lijuan Ruan (BNL)

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