The MEG Experiment

T. Morifor the MEG Collaboration

MEG Physics• Clear signal of New Physics

Never occurs in the Standard Model

• SUSY GUT promisingUnification of 3 forces (LEP)

• Solar Neutrino mixing ( - e) is largeSuperKamiokande, SNO, KamLANDSeesaw mechanism

• Muon (g-2) may be SUSY

• And more… e

GUT, m

ICEPP, University of Tokyo Y. Hisamatsu, T. Iwamoto, T. Mashimo, S. Mihara, T. Mori, H. Nishiguchi, W. Ootani, K. Ozone, T. Saeki, R. Sawada, S. Yamada, S. YamashitaKEK, Tsukuba T. Haruyama, A. Maki, Y. Makida, A. Yamamoto, K. Yoshimura

Osaka University Y. Kuno

Waseda University T. Doke, J. Kikuchi, S. Suzuki, K. Terasawa, A. Yamaguchi, T. Yoshimura

Budker Institute, Novosibirsk L.M. Barkov, A.A. Grebenuk, D.G. Grigoriev, B, Khazin, N.M. Ryskulov

PSI, Villigen J. Egger, P. Kettle, M. Hildebrandt, S. Ritt

The MEG Collaboration

INFN & Pisa University A. Baldini, C. Bemporad, F.Cei, M.Grassi, F. Morsani, D. Nicolo’, R. Pazzi, F. Raffaelli, F. Sergiampietri, G. Signorelli

INFN & Pavia University A.de Bari, P. Cattaneo, G. Cecchet, G. Nardo’, M. Rossella

INFN & Genova University S. Dussoni, F. Gatti, D. Pergolesi, R. Valle

INFN Roma I D. Zanello

INFN & Lecce University S. Spagnolo, C. Chiri, P. Creti, M. Panareo, G. Palama’

Spokespersons: T.Mori, A.BaldiniTechnical Coordinator: S.Ritt

Detectors:• Beam line: PSI P.-R.Kettle• COBRA: KEK/Tokyo W.Ootani • Drift Chamber: PSI J.Egger• Timing Counter:Genova/Pavia/Roma G. Cecchet• Photon Detector: Tokyo/KEK/Pisa S.Mihara• Trigger: Pisa M.Grassi• DAQ/Elec.: PSI S.Ritt• Offline: S.Yamada/F.Cei/P.Cattaneo

The MEG Collaboration

The MEG Detector

Placed in SLS hall for the initial test. The installation in πE5 is planned this April.

COBRA arrived at PSI!

Excitation Test at PSIExcitation test was done between Jan.17-27,2004.Full excitation for SC and 8% excitation for NC because of limited utility at SLS.

Field mapping study is starting at SLS hall.

COBRA Magnet

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Design Ass. TestWinding & Cryo.

Deliv.PSI

Test

Field Measurement

Platform

optional wall

small rail

electronics

LXestorage compressor

LN2 line

Trigger & DAQ

HV

triplets

separator

Transport solenoid

Experiment Area Layout

2003: established beam line design

Beam2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Studies

Solenoid BTS

Triplet I + II

Target

Part 1

New Separator

Part 2Beam Line Commissioning

BTS + COBRA coupling being studied

Drift Chamber

•Final design•Know how to build it

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Full Prototype

Medium PrototypeCharge division & Cosmics

FP FP

Full Detector (18 DC)

Positron Tracker

Full Prototype Beam test

Timing Counter

Minimal CrossSection 39x30 mm

60º

PM section

PM activediameter

20º 20º8.5º

From COBRA center

105 cm

10º

25 cm

BB

0.75 T 1.05 T

-Final design in progress

-APD tests for Phi counters (trigger)

-Tests under B field planned

Timing Counter

Beam Test

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Design

Assembly

PMT Evaluation PMT procur.

Procur & Manuf.

2” Fine Mesh 19 dyn. R5924

APD Evaluation APD test APD procur.

5x5 mm APD Hmamatsu

Carbon degrader

Lead Collimator at the beam line exit

LXe Photon Detector

Beam test at PiE1 in Sept-Dec 2003

Elementary process - (essentially) at rest captured on protons:

- p 0 n - p n

0

Photon spectrum

54.9 82.9 129MeV

M/2

M/2(1cos*)

M/2

*

E=55 MeV * =

Energy measurement

FWHM

Material, leakage

Backgroundrejection

~4.5%

FWHM [%]FWHM [%]

4.3±1.0 4.8±0.4 4.6±0.7

4.5±0.6 4.5±0.3 4.5±0.6

4.1±0.9 5.0±0.5 5.0±1.6

center ofthe detector

center ofF14

center ofF21

center ofF20

center ofF15

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

30 40 50 60 70 80 90

Sigma2 threshold

Res

olut

ion

(%)

#689[6-7], trigger:S1*Xe#689[6-7], trigger:S1*Xe

Laser-Compton scattering at TERAS

10, 20, 40MeV

PSI 2003TERAS 2003alpha

PSI 2003TERAS 2003alpha

L-R timing resolutionSigma = 65 psec

•Resolution improves in proportion to 1/sqrt(Npe).

•For 52.8 MeV psec + depth resolution.

•QE improvement and wave-form analysis will help to achieve better resolution.

KSR measurementOf electron beamIn 2002

Depth (cm)

E d

epos

it/u

nit l

engt

h electron

gamma

Xe – TC timing resolutionSigma = 100 psec

Position measurement

Background and Sensitivity

July 2002 NowGamma Energy (%) 4.0-4.5 4.5-5.0*e+ Timing (nsec) 0.1* 0.1*Gamma Timing 0.1 <0.23*Gamma Position (mm) 9-10.5 4.5-9.0*Gamma acceptance 0.6 >0.4*Muon rate (108/sec) 0.2-0.3 0.2-0.3Running Time (107sec) 2.6 4.0Accidental Rate (10-14) 2.2-3.5 2.3-3.5# Accidental Events 0.6 0.690% CL Limit (10-13) 1.0-1.6 1.2-1.7

* MeasuredMore detailed calculation necessary

QE abs=1 m abs=

5% 6% 2.0%

10% 6% 1.7%

20% 6% 1.5%

Problems arising…

- PMT instability

- neutron background

Photon Detector

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Large Prototype Beam Test Beam Test

Vessel Design Assembly & Test

PMT Delivery + Testing

Refrigerator Manufactoring Assembly

Liq. Purification

Assembly Test

Manufactoring

Engineering runs

Prototype system tests• Debugging of the first board Type0 in Pisa

– A minor error fixed

• System assembled at PSI in Nov. ‘03– 100MHz synchronous operation– Negligible transmission error rate– Satisfactory operation of the analog interface

• Connection with the Large Prototype

– PMT from #0 to #31

– Collected data

• Alpha

• Led

• 0

Trigger / DAQ / Electronics

The boardType0

PMT inputs

LVDS transm.

LVDS receiv.

FADC

FPGA

configuration EPROMS

Differential drivers

package error solved with a patch board

control signals.

Internal trigger

Time [10 ns]

Am

plit

ud

e

[mV

]

Max. Amplitude (2)

Index of Max

Amplitude sum

Pulse time

Inpu

t cy

clic-b

uffer

boar

d 0

Out

put cy

clic-

buffer

boa

rd 0

Full System

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

Prototype Board

Final Prototype

Trigger

now

PMC carrier board

Joint effort with the MAGIC experiment (Uni. of Siena and INFN Pisa)

– Clock control (locking to external source)

– DRS readout with FADC

– DRS control signals

DRS

1st Prototype

Wave form digitizer - DRS

DRS (DAQ)

2002 2003 2004 2005

Test MilestoneAssemblyDesign Manufactoring

2nd Prototype

Tests1st Prototype

Boards & Chip Test

now

By May 2004: -Finish merging LXe geometry & scintillation tracking (Cei/Yamada)-ZEBRA framework for MC outputs (Cattaneo)

By July 2004:-Detector digitization (TC:Paolo, XE: Yamada/Cei, DC: Nishiguchi)

Unified MC available for the DC beam test in summer

Offline Software

More people are joining the efforts now

Coordination meeting planned in May-June

Conclusion