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Three Abstracts for QM 2011 Instrumentation Session The Heavy Flavor Tracker (HFT) The Muon Telescope Detector (MTD) A High Level (Online Tracking) Trigger for STAR (HLT). Flemming Videbaek, EPD, plus JT, et al. LiJuan Ruan , et al. Aihong Tang, et al. The STAR Detector . MTD.
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Three Abstracts for QM 2011 Instrumentation SessionThe Heavy Flavor Tracker (HFT)The Muon Telescope Detector (MTD)A High Level (Online Tracking) Trigger for STAR (HLT) Flemming Videbaek, EPD, plus JT, et al. LiJuanRuan, et al. Aihong Tang, et al.
The STAR Detector MTD EMC barrel MRPC ToF barrel 100% ready for run 10 (now!) EMC End Cap • hello FMS BBC FPD TPC FHC PMD Completed DAQ1000 HLT Ongoing R&D HFT FGT
The HFT – The Question Spyros Margetis
The HFT – The Challenge • Primary Challenges • Neutral particle decay • Proper lifetime, c, 123 m • Find a common vertex away from the primary vertex • Identify daughters, measure pT, and reconstruct the invariant mass The STAR HFT has the capability to reconstruct the displaced vertex of D0 K (B.R 3.8%, c = 123 m) ΛcKp (B. R. 5.0%, c = 59.9 m) and more …
The HFT – The configuration SSD 30 IST Beampipe • The HFT puts 4 layers of Silicon around the vertex • Provides ~20 m space point resolution on tracks • Works at high rate (~ 800 Hz – 1K) • Does topological reconstruction of open charm • Will be ready for the 2014 run Pixel Detector 20 10 0 0 -10 -20 -30
The MTD - Design Concept A detectorwith long-MRPCs covers the whole iron bars and leave the gaps in- between uncovered. Acceptance: 45% at ||<0.5 117 modules, 1404 readout strips, 2808 readout channels Long-MRPC detector technology, HPTDC electronics (same as STAR-TOF)
The MTD - Physics Motivation • A large area of muon telescope detector(MTD) at mid-rapidity, allowsforthe 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 muonsfrom thesemi-leptonic decays of heavy flavorhadrons • 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+Aucollsions • - excellent mass resolution, • - separate different upsilon states • - e- correlation to distinguish heavy flavor production frominitial lepton pair production
The MTD - Single Muon and J/ Efficiency G. Lin, Yale Univ. J/ efficiency • muon efficiency at |η|<0.5: 36%, pionefficiency: 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, TOFand dE/dx • dimuon trigger enhancement factor from online trigger: 40-200 in Au-Au (central collisions)
Quarkonium dissociation temperatures – Digal, Karsch, Satz The MTD - High Mass Di-muon Capabilities 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 BJ/ 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 …
Distinguish Heavy Flavor from Initial Lepton Pair Production: e- Correlations 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
The MTD - Summary • Charm contribution to di-lepton spectrum measurement is essential to obtain the thermal radiation from QGP and understand in-medium modifications of vector mesons at RHIC. • MTD will advance our knowledge of Quark Gluon Plasma: - trigger capability for low to high pT J/ in central Au+Aucollsions - excellent mass resolution, separate different upsilon states - e-muon correlation to distinguish heavy flavor production from initial lepton pair production - rare decay and exotics … - different background contribution provides complementary measurements for dileptons • The prototype of MTD works at STAR from Run 7 to Run 10. L. Ruan et al., Journal of Physics G: Nucl. Part. Phys. 36 (2009) 095001; 0904.3774; Y. Sun et al., NIMA 593 (2008) 430. • 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.
The HLT HFT MTD SL3 SL3 SL3 BEMC TOF Total 24 SL3 machines GL3 GL3 • Sector tracking (SL3) in DAQ machines (24 in total, one per TPC sector) • Information from subsystems (SL3 and others) are sent to Global L3 machines (GL3) where an event is assembled and a trigger decision is made.
The HLT - Motivation • Over the next five years RHIC is expected to increase its delivered luminosity to 8x1027cm-1s-1 for AuAu collisions at 200 GeV and 6x1031cm-1s-1(1.5x1032cm-2s-1) for pp collisions at 200 (500) GeV. • To cope with the high collision rate, STAR has upgraded the DAQ system. • The improved data taking capability, imposes a challenge for STAR • computing resource in terms of CPU time and tape storage • Data analysis: struggle with large data volume and suffer long analysis cycles • By implementing an HLT it will be possible to reduce the amount of data written to tape by selecting desirable events while still maintaining a high sampling rate. The HLT will fully utilize the delivered luminosity for a wide range of triggers. • With the HLT, all the upgraded components will be able to perform at their full potential and will be performing beyond STAR’s current trigger capabilities.
The HLT – Physics agenda • Heavy flavor measurement, EM probes • J/ψ production and flow for exploringthe unexpectedly fast thermalizationat RHIC. Access in-medium modification of vector mesons via di-lepton invariant mass spectra. • Search for exotics • strangelets, antimatter, hypernuclei etc. • High pt probe • energy loss, jets Interesting physics with the HLT, fast output with the HLT
The HLT – Recent physics results Anti-α discovered ! Paper submitted to Nature. Without HLT, STAR would have eventually seen anti-α but LHC is trying to scoop us. It is a race to the publisher.
The HLT – Recent progress on R & D Topology triggers Potential for new discoveries. Computing intensive, must use GPU acceleration. R & D is ongoing.
The HLT – Recent progress on R&D – online ’s V0 finding runs 60 times faster than the standard CPU v0 finder, after optimizing the algorithm with GPU acceleration. An online farm of 20 – 60 PCs with GPU is needed. Experience gained can benefit other computing intensive tasks.
The HLT – Recent progress on R & D Vertex finding Precision comparable to offline when combined with HFT hits.
The HLT – Summary With HLT we can do compelling physics fast (this is proven !) Good physics potential with GPU upgrades. R & D is progressing well.
Three projects – Three Compatible Schedules $14-16M $1.7 M $2.5 M Finish HFT in time for the 2014 run Finish MTDproject by Mar, 2014 and make 80% of the full system ready for year 2014 run HLT funded and under development through FY15, but continuously available