Bernhard Schmidt DESY - HH PRC open session, October 30, 2002 HERA-B.
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Transcript of Bernhard Schmidt DESY - HH PRC open session, October 30, 2002 HERA-B.
Bernhard SchmidtDESY - HH
PRC open session, October 30, 2002
HERA-B
Status of “run 2000” analysis
in press submitted
- nearing completion
Some additional theses ongoing
There are no more data left to analyze
Detector status
Status (compared to 2000)
VDS Fully operational (always was)
ITR Getting into operation…
OTR Improved stability, less noise
RICH Fully operational as in 2000
ECAL Substantially improved
Muon Stable, not perfect but working
ITR
• HV training completed (425 hours operation), stability ok
• HV problems: 4 (160) chambers in-operational (1 cathode, 3 GEM)
acceptable level• Hit efficiency: (90 - 95%) & S/N (16-24) looks ok
• Alignment : first iteration
done
chambers of MS01 layer
ITR-2• New problem observed recently
~25% of channels show nosignal !
normal chamber abnormal chamberREASONUNCLEAR
Due to high redundancy in ITR:Coverage and efficiency of trackingstill sufficient
Run 19990
ITR-tracks at exit of PC section
Worrisome but not fatal
OTR• Fully operational in trigger and for tracking• HV problems level out :
mean time between failures at 58 h (since May 2002)• Noise level improved considerably
0
100
200
300
400
500
600
MC PC1 PC2 PC3 PC4 TC1 TC2 MC1 PC1 PC2 PC3 PC4 TC1 TC2
2000
2002
2000 RECENT
GOOD 80.4 % 93.3 %
NOISY 5.1 % 1.5 %
DEAD 14.5 % 5.2 %
Channel statisticsthreshold, noise at 1%
(-) (+)
Cell efficiency >95 %,fine for triggering and tracking
ECAL• Fully operational and
calibrated with (1%)• Dramatically improved
performance compared to 2000( noise, stability, spatial resolution)
Calibration precision
1 %
0
ECAL-2
J/ee signals
• improved PID with ECAL• no BR tag required to see J/
-1 < E/p < 3
Muon System• Operational, some non-working chambers in MU1, not critical• No new HV problems since May 2002 • Efficiency of pad read out: on average 88±3 % (include. dead
channels), no major holes
Not perfect, but sufficient for triggering
Muon tracks at MU1 position
J/->µµonline
TRIGGER and DAQ status : FLT
• FLT routinely used for J/ triggering now • High level of understanding but still some mysteries • single track efficiencies usable (25% µ-ons, 60% for electrons )
• FLT - pair trigger works
trigger schemes
• No FLT-pairs, but FLT(1 track + 1 pre-trigger) & SLT(2tracks)
advantage : much less affected by FLT efficiency (OR inst. AND) covers ITR for second track (acceptance at xF> 0)
star mode
achieved J/ rates:
400 J/ per hour and MHz interaction rate (e+µ)
? Dead time, achievable interaction rate ?
Typical : 30 % DT at 3 MHzSeen : 0% DT at 3 MHz -> ?
> 800 J/ per hour
We hope to get ~ 1000 J/ per hour these days.beam & DAQ conditions
work ongoing
Status of Commissioning
running in 2002 so far
Many thanks to HERA for giving us beam in hard times
20 %
70 %
Readiness for data taking• Spectrometer performance
Carbon target: ~ 7•106 events
K0 0 0
E/p
Cou
nts
Mass (GeV/c2)
K+K-
With RICH PID.
K*K-+
Statistics:KS ~ 90200 ~ 20000 ~ 9700
Readiness…
Spectrometer considerably improved since 2002
Performance and reliability of sub-detectors Calibration and alignment Reconstruction algorithms Data Quality Monitoring….. Track finding efficiency
(real data)2000 : 86.9 ± 2.3 %2002 : 96.5 ± 2.0 %
Readiness.. • J/ trigger (signals, rates)
Collection rate:
1000 J/psi per real hour(both channels)
almost at hand
’J/
ee
Physics goals & Run plans
Measurement of the b cross sectionPublishable charmonium physicsInvestigation of physics program beyond 2002
The initial goal for 2002
2•106 J/months running
We Are Ready To Take These Data
we need SERIOUS physics data before shutdown OR
collaboration will collapse
- complicated situation with HERA & planned new shutdown-
• Reduced time scale : 52 days stable running • with existing performance :
• lower limit for meaningful charmonium program and B-cross section measurement
• Mandatory prerequisite : stable and reliable HERA operation (moderate currents, no aggressive machine experiments..)
• Run schedule : 75 % charmonium prod.25% min.bias, calibration, tests..
Physics goal & run plan - present planning
350.000 J/c - 6.000 ’ - 350 b J/
~1/6 of planned data sample
Perspectives and Outlook
• HERA-B in better shape than ever• Ready to take serious physics data NOW
We need these data