1. Peter-Raymond KettleMEG Review February 20091 MEG 2008 Run Run Coordinator’s view E e /E Max 

2. Peter-Raymond KettleMEG Review February 20092 Situation - Review Feb. 2008 Back to “Square One” - TOTAL Detector DISMANTLED post 2007 Engineering Run - for Maintenance/Repair /Improvement TCs: Fibre light-leak + new N 2 Bags + APD amplifier/electronics TCs: Fibre light-leak + new N 2 Bags + APD amplifier/electronics DCs: Support Structure + new Target Angle + HV Investigation DCs: Support Structure + new Target Angle + HV Investigation Calo: new HV Feed-thro’s + LN 2 Cooling-pipe mod. (heat-load) + lnvest. LXe Light-Yield mod. Purification system Calo: new HV Feed-thro’s + LN 2 Cooling-pipe mod. (heat-load) + lnvest. LXe Light-Yield mod. Purification system C-WC-W BTSBTS Calo.Calo. DS-EC + IS DS-EC DCsDCs TCsTCs TCsTCs ECEC

3. Peter-Raymond KettleMEG Review February 20093 2008 Beam Time & Constraints 2008 Run Goals: final beam operational conditions to be tuned/optimized {(  -,  - & p-beams C-W)} final beam operational conditions to be tuned/optimized {(  -,  - & p-beams C-W)} Full set of detector calibrations + optimization/exploitation of various techniques Full set of detector calibrations + optimization/exploitation of various techniques optimized detector/trigger settings optimized detector/trigger settings as fuller set of information as possible, necessary for Data-analysis as fuller set of information as possible, necessary for Data-analysis + “Long-term” Goal of understanding our Detector + “Long-term” Goal of understanding our Detector Max. Expectation MEG-Physics Data ~ 16 weeks Max. Expectation MEG-Physics Data ~ 16 weeks End-of-Shutdown

4. Peter-Raymond KettleMEG Review February 20094 Planning & Organization Total of 62 persons for 959 shifts (Full Run Only) Basic Run Layout Full Run Part I CEX Run + Trigger Setup + calibrations Detector monitoring Full Run Part I CEX Run + Trigger Setup + calibrations Detector monitoring Parasitic Run Beam optimization in parallel with Debug, Tune & Calibrate Parasitic Run Beam optimization in parallel with Debug, Tune & Calibrate Full Run Part II Pre-physics data check Physics Data (MEG + RD) Full Run Part II Pre-physics data check Physics Data (MEG + RD) 2 Shift 2 ShiftCoordinators  7 weeks tot. 2 Shift 2 ShiftCoordinators  7 weeks tot. 13 Shift Coordinators 13 Shift Coordinators  2 weeks/person  2 weeks/person 13 Shift Coordinators 13 Shift Coordinators  2 weeks/person  2 weeks/person Run Coordinator Run Coordinator Parasitic Run Full Run 12 Hr Shifts: 1 DAY SHIFT (Beam Group) 10:00 – 22:00 1 DAY SHIFT (Beam Group) 10:00 – 22:00 1 NIGHT SHIFT max. 22:00 – 10:00 1 NIGHT SHIFT max. 22:00 – 10:00 1 Shift Leader Nights Manned by Detector Experts Manned by Detector Experts 12 Hr Shifts: 1 DAY SHIFT (Beam Group) 10:00 – 22:00 1 DAY SHIFT (Beam Group) 10:00 – 22:00 1 NIGHT SHIFT max. 22:00 – 10:00 1 NIGHT SHIFT max. 22:00 – 10:00 1 Shift Leader Nights Manned by Detector Experts Manned by Detector Experts 8 Hr Shifts: 1 DAY SHIFT 07:00 – 15:30 1 DAY SHIFT 07:00 – 15:30 1 EVENING SHIFT 15:00 – 23:30 1 EVENING SHIFT 15:00 – 23:30 1 NIGHT SHIFT 23:00 – 07:30 1 NIGHT SHIFT 23:00 – 07:30 1 Shift Leader + 1 Crew Member 8 Hr Shifts: 1 DAY SHIFT 07:00 – 15:30 1 DAY SHIFT 07:00 – 15:30 1 EVENING SHIFT 15:00 – 23:30 1 EVENING SHIFT 15:00 – 23:30 1 NIGHT SHIFT 23:00 – 07:30 1 NIGHT SHIFT 23:00 – 07:30 1 Shift Leader + 1 Crew Member to allow for flexibility + continuity: Staggered & Overlapping shift system Staggered & Overlapping shift system Daily Run Meetings (on-site) Daily Run Meetings (on-site) Weekly Video Run Meeting (Collaboration-wide) Weekly Video Run Meeting (Collaboration-wide) later, weekly Video Physics Analysis Group Meeting later, weekly Video Physics Analysis Group Meeting Web-based Schedule + Shift list + “On-call” List Web-based Schedule + Shift list + “On-call” List

5. Peter-Raymond KettleMEG Review February 20095 Organization In Practice Detailed Information Access “How to” information database for shift crews on MEGWiki “How to” information database for shift crews on MEGWiki Shift List ScheduleSchedule EXAMPLES comprehensive electronic Hardware/Software comprehensive electronic Hardware/Software check-list for shift crews check-list for shift crews fully searchable & cross-referenced Electronic fully searchable & cross-referenced Electronic Logbooks for all sub-detectors & Run shift-crews Logbooks for all sub-detectors & Run shift-crews 5 Sheets easy web-based experiment/instrument easy web-based experiment/instrument control for shift-crews control for shift-crews (e.g. Beam Line – magnets, separator) (e.g. Beam Line – magnets, separator) push-button changing of rate with auto push-button changing of rate with auto magnet/slits hysteresis cycling magnet/slits hysteresis cycling

6. Peter-Raymond KettleMEG Review February 20096 Detector Synopsis TCs DCs Calo. NaI Calo: HV feedthroughs replaced HV feedthroughs replaced Liquid & Gaseous purification Liquid & Gaseous purification success LY-behaviour needs success LY-behaviour needs further study + PM gain stability Calo: HV feedthroughs replaced HV feedthroughs replaced Liquid & Gaseous purification Liquid & Gaseous purification success LY-behaviour needs success LY-behaviour needs further study + PM gain stability DCs: HV instability problems with HV instability problems with air-doping still persist!!! DCs: HV instability problems with HV instability problems with air-doping still persist!!! TCs: Fibres working, problem Fibres working, problem DAQ control of DS fibres DAQ control of DS fibres Laser temp. control problems Laser temp. control problemsTCs: Fibres working, problem Fibres working, problem DAQ control of DS fibres DAQ control of DS fibres Laser temp. control problems Laser temp. control problems C-W: proved “Essential Tool” proved “Essential Tool” Li (17.6, 14.6 MeV) + B (4.4, 11.7, 16.1 MeV) lines – Energy + Timing C-W: proved “Essential Tool” proved “Essential Tool” Li (17.6, 14.6 MeV) + B (4.4, 11.7, 16.1 MeV) lines – Energy + Timing NaI: New APD preamps New APD preamps automated mover automated mover temp. contolled APDs temp. contolled APDs  E/E ~5-6% (  )  E/E ~5-6% (  )NaI: New APD preamps New APD preamps automated mover automated mover temp. contolled APDs temp. contolled APDs  E/E ~5-6% (  )  E/E ~5-6% (  ) C-W

7. Peter-Raymond KettleMEG Review February 20097 Trigger + DAQ Trigger + Splitters Trigger + Splitters Online Cluster Megonxx Online Cluster Megonxx Multi-trigger implementation: Multi-trigger implementation: Final Complement of 29 Triggers implemented Final Complement of 29 Triggers implemented multiple & pre-scaled (MEG=11, RMD=5) multiple & pre-scaled (MEG=11, RMD=5) Single & Coincidence detector triggers crucial Single & Coincidence detector triggers crucial for monitoring/Calibration for monitoring/Calibration e.g. 7 Li, 11 B C-W, , CR, LED – RMD,  0,  0 -Dalitz e.g. 7 Li, 11 B C-W, , CR, LED – RMD,  0,  0 -Dalitz CEX software collimators LXe responce CEX software collimators LXe responce Direction matching    e  (planned TC fibres) Direction matching    e  (planned TC fibres) too slow  still XEC PMT-index + TC-bar(index,z) too slow  still XEC PMT-index + TC-bar(index,z) where z from bar charge-ratio where z from bar charge-ratio Trig. Monitoring via (cyclic-buffers) Trig. Monitoring via (cyclic-buffers) Multi-trigger implementation: Multi-trigger implementation: Final Complement of 29 Triggers implemented Final Complement of 29 Triggers implemented multiple & pre-scaled (MEG=11, RMD=5) multiple & pre-scaled (MEG=11, RMD=5) Single & Coincidence detector triggers crucial Single & Coincidence detector triggers crucial for monitoring/Calibration for monitoring/Calibration e.g. 7 Li, 11 B C-W, , CR, LED – RMD,  0,  0 -Dalitz e.g. 7 Li, 11 B C-W, , CR, LED – RMD,  0,  0 -Dalitz CEX software collimators LXe responce CEX software collimators LXe responce Direction matching    e  (planned TC fibres) Direction matching    e  (planned TC fibres) too slow  still XEC PMT-index + TC-bar(index,z) too slow  still XEC PMT-index + TC-bar(index,z) where z from bar charge-ratio where z from bar charge-ratio Trig. Monitoring via (cyclic-buffers) Trig. Monitoring via (cyclic-buffers) lcmeg05lcmeg05 lcmeg04lcmeg04 lcmeg03lcmeg03 lcmeg02lcmeg02 lcmeg01lcmeg01 Offline Cluster lcmeg Offline Cluster lcmeg Limits: DAQ/DRS readout limited by VME (83MB/s) DAQ/DRS readout limited by VME (83MB/s) ~ 30 events/s full waveforms (threading) ~ 30 events/s full waveforms (threading) Online (backend) 2TB storage Online (backend) 2TB storage Offline (lcmeg) 64 CPUs + 104TB disk Offline (lcmeg) 64 CPUs + 104TB disk “Lazylogger” autocopy Online  Offline “Lazylogger” autocopy Online  Offline factor 2 compression offline factor 2 compression offline DRS3 – partly implemented (clock signals, temp eff. Etc.) DRS v2 + part v3

8. Peter-Raymond KettleMEG Review February 20098 Arsenal of Standard Calibration Tools LED PMT Gain Higher V with light att. Can be repeated frequently alpha PMT QE & Att. L Cold GXe LXe Laser (rough) relative timing calib. < 2~3 nsec Nickel  Generator 9 MeV Nickel γ-line NaI Polyethylene 0.25 cm Nickel plate 3 cm 20 cm quelle onon off Illuminate Xe from the back Source (Cf) transferred by comp air  on/off Proton Acc Li(p,  )Be LiF target at COBRA center 17.6MeV  ~daily calib. Can be used also for initial setup  K Bi Tl F Li(p,  0) at 17.6 MeV Li(p,  1) at 14.6 MeV  radiative decay  0    - + p   0 + n  0   (55MeV, 83MeV)  - + p   + n (129MeV) 10 days to scan all volume precisely (faster scan possible with less points) LH 2 target  e+e+ e-e- e e     Lower beam intensity < 10 7 Is necessary to reduce pile- ups Better  t, makes it possible to take data with higher beam intensity A few days ~ 1 week to get enough statistics MEG Detector StandardCalibrations StandardCalibrations NOT YET STANDARD

9. Peter-Raymond KettleMEG Review February 20099 New & Improved Calibration Techniques Multiple calibration techniques proved Essential for deconvoluting complex effects (1)New Lithium TetraborateTarget (Li 2 B 4 O 7 ) for C-W: - advantage both Li- & B-lines simultaneously available without large X-section of F (~ 6-7 MeV), from LiF simultaneously available without large X-section of F (~ 6-7 MeV), from LiF >16.1 MeV >11.7 MeV 4.4 MeV 11.7 & 4.4 MeV  s Coincident in time (94%) & no angular correlation & no angular correlation 11.7 & 4.4 MeV  s Coincident in time (94%) & no angular correlation & no angular correlation Li used for E-calibration, B can be used for Δ tabs (LXe-TC) or Δt(TC-TC(inter-bar)) Li used for E-calibration, B can be used for Δ tabs (LXe-TC) or Δt(TC-TC(inter-bar)) (2) New timing calibration technique during CEX: - use Dalitz decay for intercalibrating LXe & TC detectors by tracking e + in DCs (  0 → e + e -  ) intercalibrating LXe & TC detectors by tracking e + in DCs (  0 → e + e -  ) used successfully for measuring absolute Δt(LXe-TC) of reference TC-bar, can used successfully for measuring absolute Δt(LXe-TC) of reference TC-bar, can then intercalibrate bar using Boron e.g. then intercalibrate bar using Boron e.g. “Energy” deposit in TC Energy deposit in XEC 4.4 and 11.6 MeV Compton Edges (3) Am/Be – neutron source as a source of 4.44 MeV Gammas from 2 + state of 12 C * via 9 Be(α,n) 12 C Am/Be ≡ Li LY

10. Peter-Raymond KettleMEG Review February 200910 Calibration Techniques cont. (4) Use of tuned monochromatic positron beam being investigated as a means of e.g. studying our positron spectrometer tracking efficiency vs. emission angle or momentum, with high statistics, in a momentum range equivalent to real MEG- conditions!!! Mechanism:positron-Nucleus elastic scattering from light nuclei at around Mechanism: positron-Nucleus elastic scattering from light nuclei at around P e ~ 50 MeV/c “Coherent” P e ~ 50 MeV/c “Coherent” nuclear recoil, spin-effects, magnetic terms all ~ negligable nuclear form-factor introduces a small effect X-sections “well known”  basically “Mott-scattering” Mechanism:positron-Nucleus elastic scattering from light nuclei at around Mechanism: positron-Nucleus elastic scattering from light nuclei at around P e ~ 50 MeV/c “Coherent” P e ~ 50 MeV/c “Coherent” nuclear recoil, spin-effects, magnetic terms all ~ negligable nuclear form-factor introduces a small effect X-sections “well known”  basically “Mott-scattering” Reality: MEG beam can be tuned to give ~ 50 MeV/c e + with a max. rate of ~ 8· 10 8 e + /s at 2mA proton current with ΔP/P ~ 7% FWHM  obviously would reduce ΔP/P to achieve “monochromaticity” though at the cost of rate. Wien-filter does not work at this momentum to sufficiently separate e + from  + but a 2mm CH 2 -degrader at the collimator system in front of BTS DOES! Carbon target ρ ~ 2.1 g/cm 3 t < 1cm thick, and 10 7 e + /s Integrated X-section: 30 ° < Δθ < 120 ° & Δφ =   2.5 mbarn  ~ 1300 events/s Carbon target ρ ~ 2.1 g/cm 3 t < 1cm thick, and 10 7 e + /s Integrated X-section: 30 ° < Δθ < 120 ° & Δφ =   2.5 mbarn  ~ 1300 events/s

11. Peter-Raymond KettleMEG Review February 200911 2008 Run Conditions  - target inclinationangle inclinationangle (1)New Target Angle: - modification DC Support Structure optimal @ ~ 21° to match beam stopping distribution etc. Prior 2008 limited by DC Support structure to max. 13° (1)New Target Angle: - modification DC Support Structure optimal @ ~ 21° to match beam stopping distribution etc. Prior 2008 limited by DC Support structure to max. 13° Target Inclination 2008  = (20.5 ± 0.3)° Conventional = (20.6 ± 0.2)° Conventional = (20.6 ± 0.2)° Photogrammetric Photogrammetric (outside COBRA) = (20.4 ± 0.2)° (outside COBRA) = (20.4 ± 0.2)° Photogrammetric Photogrammetric (inside COBRA) = (20.3 ± 0.3)° (inside COBRA) = (20.3 ± 0.3)° Conventional = (20.6 ± 0.2)° Conventional = (20.6 ± 0.2)° Photogrammetric Photogrammetric (outside COBRA) = (20.4 ± 0.2)° (outside COBRA) = (20.4 ± 0.2)° Photogrammetric Photogrammetric (inside COBRA) = (20.3 ± 0.3)° (inside COBRA) = (20.3 ± 0.3)° (2)Beam Intensities: - apart from “Normal” beam intensity 2 further tunes were optimized based on standard degrader 300  m Mylar – “Ultra-low” & “High” (2)Beam Intensities: - apart from “Normal” beam intensity 2 further tunes were optimized based on standard degrader 300  m Mylar – “Ultra-low” & “High” Measured values at 7% air contamination 1% Air ~ 10  m Mylar degrader - Not compensated for in 2008!!! Mode R  Measured Rate COBRA at 2mA R stop Stopping Rate at 2mA (ε STOP = 0.794) “High” 8.4  10 7  + s -1 6.7  10 7  + s -1 “Normal” 3.5  10 7  + s -1 ~ 2.8  10 7  + s -1 ~ 2.8  10 7  + s -1 “Ultra-low” 1.5  10 6  +s -1 ~ 1.2  10 6  + s -1

12. Peter-Raymond KettleMEG Review February 200912 Run Conditions cont. (3)COBRA He-Concentration: - for DC HV-stability reasons air-doping of COBRA Environment was necessary (3)COBRA He-Concentration: - for DC HV-stability reasons air-doping of COBRA Environment was necessary 637061 62 60 DS-ECUS-ECCOBRA Mean Air-doping (Physics Run Part1 + 2) = 6% 1% Air ~ 10  m Mylar degrader Not compensated for!!! P61 blue P70 green P63 red P60 light blue blue P61 blue P70 green P63 red P60 light blue blue O 2 -sensor Part1: 11/9 (01 00 ) – 20/10 (01 00 ) 11/9 (01 00 ) – 20/10 (01 00 ) 35 days 35 daysPart1: 11/9 (01 00 ) – 20/10 (01 00 ) 11/9 (01 00 ) – 20/10 (01 00 ) 35 days 35 days Physics Run Classification: MEG Data ONLY(before/after DC COBRA test) MEG Data ONLY(before/after DC COBRA test) Physics Run Classification: MEG Data ONLY(before/after DC COBRA test) MEG Data ONLY(before/after DC COBRA test) P61,P70, P63 96% He He92% 95% 93% Part 1 Part 2 Part2: 27/10 (11 49 ) – 06/11 (23 59 ) – 23/12 11 + 32.5 days Part2: 27/10 (11 49 ) – 06/11 (23 59 ) – 23/12 11 + 32.5 days

13. Peter-Raymond KettleMEG Review February 200913 2008 Beam Time Influences (1) Calorimeter: (1) Calorimeter: 2007 Light-yield << expected both for  s &  s (Q/A)  /(Q/A)  ~ 1.25 expect LP~ 1.92!!! Contamination? new purifier installed 2008 Significant time was invested with monitoring/understanding of LY vs. purification time Using C-W Li, CR,  s & LEDs Liquid & Gaseous & No purification scenarios studied (1) Calorimeter: (1) Calorimeter: 2007 Light-yield << expected both for  s &  s (Q/A)  /(Q/A)  ~ 1.25 expect LP~ 1.92!!! Contamination? new purifier installed 2008 Significant time was invested with monitoring/understanding of LY vs. purification time Using C-W Li, CR,  s & LEDs Liquid & Gaseous & No purification scenarios studied → Induced Noise on electronics Liq.P → Induced Noise on electronics → minimal Noise Gas.P → minimal Noise → Induced Noise on electronics Liq.P → Induced Noise on electronics → minimal Noise Gas.P → minimal Noise Questions to answer: can one survive without Liq.P for 3 weeks between inter-accelerator shutdowns and only rely on GasP? What happens to LY without any purifications? - 0.7%/5 days Gas.P Liq.P Initial Purification May 2008 ssss ssss also CR same response! L-Y 3 Major factors influenced the maximizing of the available beam time for Physics Data-taking – such that substantial extra investigation time was necessary  3 Major factors influenced the maximizing of the available beam time for Physics Data-taking – such that substantial extra investigation time was necessary  No.P Calorimeter – Calorimeter – Light-yield + PMT gain drift Electronics - Noise + Baseline stability Electronics - Noise + Baseline stability Drift Chambers - HV stability Drift Chambers - HV stability Calorimeter – Calorimeter – Light-yield + PMT gain drift Electronics - Noise + Baseline stability Electronics - Noise + Baseline stability Drift Chambers - HV stability Drift Chambers - HV stability

14. Peter-Raymond KettleMEG Review February 200914 Beam Time Influences Calo.- cont. Variations in no Photo-electrons seen…LY changing + ? PMT- Gain variation seen vs. Beam rate drastic during CEX PMT- Gain variation seen vs. Beam rate drastic during CEX changes of several % possible!! Stable at low rate changes of several % possible!! Stable at low rate PMT Gain well monitored using LEDs …Reason for instability? PMT Gain well monitored using LEDs …Reason for instability? in principle effect already compensated for “zener diodes”!!! in principle effect already compensated for “zener diodes”!!! could this be aging? could this be aging? Thus frequent LED calibrations used as gain normalization for Thus frequent LED calibrations used as gain normalization for light/energy measurements light/energy measurements time constants for rate-changes measured (beam-blocker) time constants for rate-changes measured (beam-blocker) therefore in principle all ingredients available for corrections therefore in principle all ingredients available for corrections Variations in no Photo-electrons seen…LY changing + ? PMT- Gain variation seen vs. Beam rate drastic during CEX PMT- Gain variation seen vs. Beam rate drastic during CEX changes of several % possible!! Stable at low rate changes of several % possible!! Stable at low rate PMT Gain well monitored using LEDs …Reason for instability? PMT Gain well monitored using LEDs …Reason for instability? in principle effect already compensated for “zener diodes”!!! in principle effect already compensated for “zener diodes”!!! could this be aging? could this be aging? Thus frequent LED calibrations used as gain normalization for Thus frequent LED calibrations used as gain normalization for light/energy measurements light/energy measurements time constants for rate-changes measured (beam-blocker) time constants for rate-changes measured (beam-blocker) therefore in principle all ingredients available for corrections therefore in principle all ingredients available for corrections 2007Level CEX NormBeam Off 1/2 CEX  - PM Gain LY nearly reached optimal value LY  is constant LY  > LY nearly reached optimal value LY  is constant LY  > How does this affect our energy scale Extrapolated for low-energy low-rate? How does this affect our energy scale Extrapolated for low-energy low-rate?

15. Peter-Raymond KettleMEG Review February 200915 Effect on Energy Scale ~30 mins. B-B “opened” B-B “closed” C-W CEX For our Photon Energy-scale we extrapolate from “Low-energy” “Low-rate” C-W data to “High-energy” “High-rate” CEX pion data What is the rate dependency at CEX-rates? Not enough LED data taken during intial CEX  Hence new “mini-CEX” run at end of December For our Photon Energy-scale we extrapolate from “Low-energy” “Low-rate” C-W data to “High-energy” “High-rate” CEX pion data What is the rate dependency at CEX-rates? Not enough LED data taken during intial CEX  Hence new “mini-CEX” run at end of December Rate-dependent effect ~ 4% discrepancy from Extrapolation to CEX energies before correction from “Mini-CEX” After? better but not perfect! More work needed better but not perfect! More work needed Before Correction

16. Peter-Raymond KettleMEG Review February 200916 Beam Time Influences – cont. (2) Electronics: baseline instability as well higher noise content on DRS i/ps (2) Electronics: baseline instability as well higher noise content on DRS i/ps 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from defective Calorimeter feed-thro’s. defective Calorimeter feed-thro’s.  all boards modified with new higher rated  all boards modified with new higher rated diodes & resistors changed diodes & resistors changed (ii) burst-noise suppressed with external shielding of flat-band (ii) burst-noise suppressed with external shielding of flat-band calorimeter cables between splitter & DRS calorimeter cables between splitter & DRS  external shielding added to all calo-cables between splitter & DRS  external shielding added to all calo-cables between splitter & DRS (2) Electronics: baseline instability as well higher noise content on DRS i/ps (2) Electronics: baseline instability as well higher noise content on DRS i/ps 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from 2 reasons found – (i) i/p stages (diodes + resistors)of splitter damaged by sparking from defective Calorimeter feed-thro’s. defective Calorimeter feed-thro’s.  all boards modified with new higher rated  all boards modified with new higher rated diodes & resistors changed diodes & resistors changed (ii) burst-noise suppressed with external shielding of flat-band (ii) burst-noise suppressed with external shielding of flat-band calorimeter cables between splitter & DRS calorimeter cables between splitter & DRS  external shielding added to all calo-cables between splitter & DRS  external shielding added to all calo-cables between splitter & DRS (3) Drift Chambers: HV-stability of chambers persists, seems to be a time (3) Drift Chambers: HV-stability of chambers persists, seems to be a time dependency before onset & seems worsened by CEX pion beam then worsens dependency before onset & seems worsened by CEX pion beam then worsens with time. Gives a complicated time-dependent e+ detector efficiency with time. Gives a complicated time-dependent e+ detector efficiency  Air doping + overpressure + gas-mixture investigated during dedicated  Air doping + overpressure + gas-mixture investigated during dedicated combined electronics/Calo./DC maintenance week combined electronics/Calo./DC maintenance week (3) Drift Chambers: HV-stability of chambers persists, seems to be a time (3) Drift Chambers: HV-stability of chambers persists, seems to be a time dependency before onset & seems worsened by CEX pion beam then worsens dependency before onset & seems worsened by CEX pion beam then worsens with time. Gives a complicated time-dependent e+ detector efficiency with time. Gives a complicated time-dependent e+ detector efficiency  Air doping + overpressure + gas-mixture investigated during dedicated  Air doping + overpressure + gas-mixture investigated during dedicated combined electronics/Calo./DC maintenance week combined electronics/Calo./DC maintenance week He-Con C He-Con C. ΔP(DC-COBRA) ΔP(DC-COBRA). Anode Hit-map Anode Hit-map. 0% 100%

17. Peter-Raymond KettleMEG Review February 200917 Beam Time/Data In view of the complex & overlapping problems that were studied & monitored during the “Parasitic” & Part 1 Phase of the “Full Run” the following schedule evolved necessitating a mini-CEX at the end of the period to evaluate the rate dependency during the full CEX, so that the Calorimeter Energy-scale could be fully determined: In view of the complex & overlapping problems that were studied & monitored during the “Parasitic” & Part 1 Phase of the “Full Run” the following schedule evolved necessitating a mini-CEX at the end of the period to evaluate the rate dependency during the full CEX, so that the Calorimeter Energy-scale could be fully determined: Parasitic Run: 19 th May- 3 rd July ~ 7 weeks Beam Tests/Tuning (4.5 weeks) Beam Tests/Tuning (4.5 weeks) Full Run Part 1: 11 th July – 31 st August ~7 weeks CEX 21 st July – 31 st August (6 weeks) CEX 21 st July – 31 st August (6 weeks) Full Run Part 2: 1 st September – 23 rd December ~16 weeks Pre-Physics Data (~ 3 weeks) Pre-Physics Data (~ 3 weeks) Physics Data Part1 35 Days Physics Data Part1 35 Days MEG Maintenance/Repair ~ 7 Days MEG Maintenance/Repair ~ 7 Days Physics Data Part 2 43.5 Days Physics Data Part 2 43.5 Days Mini-CEX ~ 7 Days Mini-CEX ~ 7 Days Parasitic Run: 19 th May- 3 rd July ~ 7 weeks Beam Tests/Tuning (4.5 weeks) Beam Tests/Tuning (4.5 weeks) Full Run Part 1: 11 th July – 31 st August ~7 weeks CEX 21 st July – 31 st August (6 weeks) CEX 21 st July – 31 st August (6 weeks) Full Run Part 2: 1 st September – 23 rd December ~16 weeks Pre-Physics Data (~ 3 weeks) Pre-Physics Data (~ 3 weeks) Physics Data Part1 35 Days Physics Data Part1 35 Days MEG Maintenance/Repair ~ 7 Days MEG Maintenance/Repair ~ 7 Days Physics Data Part 2 43.5 Days Physics Data Part 2 43.5 Days Mini-CEX ~ 7 Days Mini-CEX ~ 7 Days Normal Physics Data-taking: MEG 11-mixed trigger 6.5Hz Trigger Rate, LT~ 80-83% MEG 11-mixed trigger 6.5Hz Trigger Rate, LT~ 80-83% Daily LED-calibration beam “off” Daily LED-calibration beam “off” 3/week Full-calibration LED beam “on” +LED beam “off” 3/week Full-calibration LED beam “on” +LED beam “off” + C-W (Li) + C-W (B) +  s + C-W (Li) + C-W (B) +  s 1/week 24Hrs RMD 5-mixed trigger data 1/week 24Hrs RMD 5-mixed trigger data Normal Physics Data-taking: MEG 11-mixed trigger 6.5Hz Trigger Rate, LT~ 80-83% MEG 11-mixed trigger 6.5Hz Trigger Rate, LT~ 80-83% Daily LED-calibration beam “off” Daily LED-calibration beam “off” 3/week Full-calibration LED beam “on” +LED beam “off” 3/week Full-calibration LED beam “on” +LED beam “off” + C-W (Li) + C-W (B) +  s + C-W (Li) + C-W (B) +  s 1/week 24Hrs RMD 5-mixed trigger data 1/week 24Hrs RMD 5-mixed trigger data DATA DATA MEG ( Runs# 23987- 40997)  10859 Runs a 2k events  22.4 M Triggers  Time 49:18:50:49 RMD (Runs# 23017 – 39963)  1059 Runs a 3k events  2.99 M Triggers  Time 7:05:33:39 DATA DATA MEG ( Runs# 23987- 40997)  10859 Runs a 2k events  22.4 M Triggers  Time 49:18:50:49 RMD (Runs# 23017 – 39963)  1059 Runs a 3k events  2.99 M Triggers  Time 7:05:33:39 TBytes MEG 2008 Run DATA Taken  139 TB Total of 139 TB Data Taken 2008 Total of 139 TB Data Taken 2008

18. Peter-Raymond KettleMEG Review February 200918 Physics Data Preparation Analysis Scheme Analysis Scheme: (Physics Analysis Working Group) Pre-selection Data Reduction in form of “Pre-selection” - use very lose cuts “Conservative Criteria” “Conservative Criteria” (ensure non-biasing) 16% of triggered events reduces data to 16% of triggered events “Blinding” in “pre-selected” data Incorporate “Blinding” in “pre-selected” data use “Hidden” Signal-box on parameters E  & T e  use “Hidden” Signal-box on parameters E  & T e  directly via MEGAnalyzer with widths directly via MEGAnalyzer with widths ~ ± 4.8 MeV & ± 1.5 ns respectively ~ ± 4.8 MeV & ± 1.5 ns respectively Perform Likelihood Analysis on “final revealed data” Perform Likelihood Analysis on “final revealed data” after optimized background study outside “signal-box” after optimized background study outside “signal-box”  “side-bands”  “side-bands” Probability Density Functions (PDFs) for Likelihood Analysis Probability Density Functions (PDFs) for Likelihood Analysis obtained partially direct from measurement & partially from MC. obtained partially direct from measurement & partially from MC. MC substantially advanced e.g. RMD + radiative corrections etc. MC substantially advanced e.g. RMD + radiative corrections etc. “Blinding” Simulation Simulation

19. Peter-Raymond KettleMEG Review February 200919 Conclusions With a consolidated effort made by the “whole” collaboration, as well as basically With a consolidated effort made by the “whole” collaboration, as well as basically starting from ”scratch” at the beginning of the 2008 we were able to achieve our goal starting from ”scratch” at the beginning of the 2008 we were able to achieve our goal of taking “True” Physics Data! of taking “True” Physics Data! despite many detector/electronics problems that were encountered we were able to despite many detector/electronics problems that were encountered we were able to dedicate 12 weeks out of the expected 16 weeks to “pure (MEG+RMD) Physics Data dedicate 12 weeks out of the expected 16 weeks to “pure (MEG+RMD) Physics Data a vast amount of calibration data was taken during the whole 2008 period which a vast amount of calibration data was taken during the whole 2008 period which served a as vital input to understanding encountered effects during the run served a as vital input to understanding encountered effects during the run – this however will continue to serve as a basis for a better understanding of our – this however will continue to serve as a basis for a better understanding of our detector with on-going analysis detector with on-going analysis several factors concerning our hardware led to a non-optimal MEG Detector in 2008 several factors concerning our hardware led to a non-optimal MEG Detector in 2008 the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity, the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity, PMT gain-stability, TC: fibre incorporation in trigger) PMT gain-stability, TC: fibre incorporation in trigger) the most worrying issue is that of the DC HV-stability – this however is being tackled the most worrying issue is that of the DC HV-stability – this however is being tackled with a large and dedicated effort by the “detector group” – the experts! and as has with a large and dedicated effort by the “detector group” – the experts! and as has been shown before, especially with “forefront” detector technology such problems been shown before, especially with “forefront” detector technology such problems CAN BE SOLVED! CAN BE SOLVED! we still have a lot of work to do & a lot of improvements are still necessary but !!! we still have a lot of work to do & a lot of improvements are still necessary but !!! the following “Expert” talks will show that the MEG Collaboration has the following “Expert” talks will show that the MEG Collaboration has a lot of dedicated & resourceful means at it’s disposal a lot of dedicated & resourceful means at it’s disposal With a consolidated effort made by the “whole” collaboration, as well as basically With a consolidated effort made by the “whole” collaboration, as well as basically starting from ”scratch” at the beginning of the 2008 we were able to achieve our goal starting from ”scratch” at the beginning of the 2008 we were able to achieve our goal of taking “True” Physics Data! of taking “True” Physics Data! despite many detector/electronics problems that were encountered we were able to despite many detector/electronics problems that were encountered we were able to dedicate 12 weeks out of the expected 16 weeks to “pure (MEG+RMD) Physics Data dedicate 12 weeks out of the expected 16 weeks to “pure (MEG+RMD) Physics Data a vast amount of calibration data was taken during the whole 2008 period which a vast amount of calibration data was taken during the whole 2008 period which served a as vital input to understanding encountered effects during the run served a as vital input to understanding encountered effects during the run – this however will continue to serve as a basis for a better understanding of our – this however will continue to serve as a basis for a better understanding of our detector with on-going analysis detector with on-going analysis several factors concerning our hardware led to a non-optimal MEG Detector in 2008 several factors concerning our hardware led to a non-optimal MEG Detector in 2008 the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity, the main issues have been addressed ( DC: HV-stability, Calorimeter: LXe-purity, PMT gain-stability, TC: fibre incorporation in trigger) PMT gain-stability, TC: fibre incorporation in trigger) the most worrying issue is that of the DC HV-stability – this however is being tackled the most worrying issue is that of the DC HV-stability – this however is being tackled with a large and dedicated effort by the “detector group” – the experts! and as has with a large and dedicated effort by the “detector group” – the experts! and as has been shown before, especially with “forefront” detector technology such problems been shown before, especially with “forefront” detector technology such problems CAN BE SOLVED! CAN BE SOLVED! we still have a lot of work to do & a lot of improvements are still necessary but !!! we still have a lot of work to do & a lot of improvements are still necessary but !!! the following “Expert” talks will show that the MEG Collaboration has the following “Expert” talks will show that the MEG Collaboration has a lot of dedicated & resourceful means at it’s disposal a lot of dedicated & resourceful means at it’s disposal