Bernhard Schmidt DESY - 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) VDSFully operational (always was) ITRGetting into operation… OTRImproved stability, less noise RICHFully operational as in 2000 ECALSubstantially improved MuonStable, 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: ( %) & S/N (16-24) looks ok Alignment : first iteration done chambers of MS01 layer
ITR-2 New problem observed recently ~25% of channels show no signal ! normal chamber abnormal chamber REASON UNCLEAR Due to high redundancy in ITR: Coverage and efficiency of tracking still sufficient Run 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 2000RECENT GOOD80.4 %93.3 % NOISY5.1 %1.5 % DEAD14.5 %5.2 % Channel statistics threshold, 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/ ->µµ online
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 x F > 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 MHz Seen : 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: ~ events K0K0 00 00 E/p Counts Mass (GeV/c 2 ) K + K - With RICH PID. K* K - + Statistics: K S ~ ~ ~ 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 section Publishable charmonium physics Investigation of physics program beyond 2002 The initial goal for 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 J/ c ’ 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