MEG Summary T Mori for MEG Collaboration February

MEG Summary T. Mori for MEG Collaboration February 9, 2005

The MEG Collaboration Spokespersons: T. Mori, A. Baldini Technical Coordinator: S. Ritt Detectors: • Beam line: • COBRA: • Drift Chamber: • Timing Counter: • Photon Detector: • Trigger: • DAQ/Elec. : • Offline: PSI P. -R. Kettle KEK/Tokyo W. Ootani PSI J. Egger Genova/Pavia/Roma G. Cecchet Tokyo/Pisa/KEK S. Mihara Pisa M. Grassi PSI S. Ritt C. Gatto/S. Yamada/F. Cei

Highlights in developments sine July 2004 Beam line Separator, BTS in construction COBRA Fringing field problem ~solved LXe Beam test w/ new PMTs, waveform digitizers, and wire alpha sources Detector cryostat in construction

Absolute time of LXe 55 Me. V normal gain 110 psec high gain 103 psec Intrinsic from LR analysis depth 110 - 64 - 61 = 65 = 56 + 33 psec LYSO target 5

Background and Sensitivity Gamma Energy (%) e+ Timing (nsec) Gamma Timing Gamma Position (mm) Gamma acceptance Muon rate (108/sec) Running Time (107 sec) Accidental Rate (10 -14) # Accidental Events 90% CL Limit (10 -13) Jan 2004 4. 5 -5. 0* 0. 1* <0. 23* 4. 5 -9. 0* >0. 4* 0. 2 -0. 3 4. 0 2. 3 -3. 5 0. 6 1. 2 -1. 7 * Measured More detailed calculation necessary Jan 2005 ~0. 15** 0. 25 -0. 35 1. 9 -3. 0 0. 6 0. 9 -1. 4 **w/ new PMTs

Schedule

Changes (~delays) in schedule Beam line BTS construction LXe Detector cryostat construction PMT delivery new problem arising -- solution foreseen DC Troubles with cathode foil production

Noise from Zener diode

2005 J Beam Time F M A M Shutdown S O N D J F Shutdown MEG Commiss. Part 2 Tgt Full Test Full Installation Proto Inst BG Test Tst Inst PMT testing + calibration Cryogenics Installation Assembly + Test Inst Trigger Test Inst DC Electr. M Field Map BTS Test LPT DAQ A P F Beam Line Drift Chamber Timing Counter Full Calorimeter J MEG Te sts COBRA J 2006 Inst A

Manpower

Mostly in healthy situation except: beam line + target Monte Carlo

Budget

We now have enough money for PMTs! a new budget for construction in Japan ~400 PMTs additional budget for ~110 PMTs in Italy Then new problems arising… LXe electronics LXe calibration equipment for last 300 liters proton beam? PSI

PREVIOUS 1982 !! e EXPERIMENT

NOW: GLAST SPACE EXPERIMENT CRYSTAL CALORIMETER CALIBRATION 180 cm target-pipe It is the old VDG of the Crystal Ball experiment ! ! they have some problems: old device, max. VDG p-energy is 400 Ke. V out of resonance: -rate reduced by factor 5000