1 jim thomas – the berkeley lab three abstracts for qm 2011 instrumentation session the heavy...

1Jim Thomas – The Berkeley Lab

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

• hello

MRPC ToF barrel100% ready for run 10

(now!)

BBC

PMD

FPD

FMS

EMC barrelEMC End Cap

DAQ1000

FGT

Completed

Ongoing

MTD

R&DHFT

TPC

FHC

HLT


The HFT – The Question

Spyros Margetis


The HFT – The Challenge

The STAR HFT has the capability to reconstruct the displaced vertex of

D0 K (B.R 3.8%, c = 123 m) Λc Kp (B. R. 5.0%, c = 59.9 m)and more …

• 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 HFT – The configuration

0

10

20

30

-30

-10

-20

Beampipe SSD

IST

Pixel Detector

0

• 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


The HFT – Technology


The MTD - Design Concept

A detector with long-MRPCs covers thewhole iron bars and leave the gaps in- between uncovered. Acceptance: 45% at ||<0.5

117 modules, 1404 readout strips, 2808 readoutchannels

Long-MRPC detector technology, HPTDCelectronics (same as STAR-TOF)


A large area of muon telescope detector (MTD) at mid-rapidity, allows for the detection of

• di-muon pairs from QGP thermal radiation, quarkonia, light vector mesons, possible correlations of quarks and gluons as resonances in QGP, and Drell-Yan production

• single muons from the semi- 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- correlation to distinguish heavy flavor production from

initial lepton pair production

The MTD - Physics Motivation


The MTD - Single Muon and J/ Efficiency

J/ efficiency

1. muon efficiency at |η|<0.5: 36%, pion efficiency: 0.5-1% at pT>2 GeV/c

2. muon-to-pion enhancement factor: 50-100

3. muon-to-hadron enhancement factor: 100-1000 including track matching, TOF and dE/dx

4. dimuon trigger enhancement factor from online trigger: 40-200 in Au-Au (central collisions)

G. Lin, Yale Univ.


The MTD - High Mass Di-muon Capabilities

1. J/: S/B=6 in d+Au and S/B=2 in central Au+Au

2. With HFT, study BJ/ X; J/ using displaced vertices

3. Excellent mass resolution: separate different upsilon states

Heavy flavor collectivity and colorscreening, quarkonia production mechanisms:J/ RAA and v2; upsilon RAA …

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


Distinguish Heavy Flavor from Initial Lepton Pair Production: e- Correlations

e- correlation simulation with Muon TelescopeDetector 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

Z. Xu, BNL LDRD 07-007; L. Ruan et al., Journal of Physics G: Nucl. Part. Phys. 36 (2009) 095001

NA60, PRL100,022302(2008)

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+Au collsions

- 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

SL3SL3 SL3SL3 SL3SL3

GL3GL3

BEMCBEMC TOFTOF

GL3GL3

HFTHFT MTDMTD

Total 24 SL3 machines

• 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.


• 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 - Motivation


The HLT – Physics agenda

• Heavy flavor measurement, EM probes

J/ψ production and flow for exploring the unexpectedly fast thermalization at 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 – Tracking performance


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

Potential for new discoveries.Computing intensive, must use GPU acceleration.R & D is ongoing.

Topology triggers


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

Precision comparable to offline when combined with HFT hits.

Vertex finding


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.


FY09 FY10 FY11 FY12 FY13 FY14 FY15

HFT Construction

HFTOperation

MTDConstruction

MTDOperation

HLT Development

HLT Operation

Finish HFT in time for the 2014 runFinish MTD project by Mar, 2014 and make 80% of the full system ready for year 2014 runHLT funded and under development through FY15, but continuously available

Three projects – Three Compatible Schedules

$2.5 M

$1.7 M

$14-16M

1 jim thomas – the berkeley lab three abstracts for qm 2011 instrumentation session the heavy...

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run slide

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muon telescope detector