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