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WG4 Summary and Future Plans. The muon trio and more. B. Lee Roberts Department of Physics Boston University. roberts@bu.edu http://physics.bu.edu/roberts.html. Lepton Flavor Violation Muon MDM (g-2) chiral changing Muon EDM. The Muon Trio:. MEG. MECO. PRIME.
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WG4 Summary and Future Plans The muon trio and more B. Lee Roberts Department of Physics Boston University roberts@bu.edu http://physics.bu.edu/roberts.html B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Lepton Flavor Violation Muon MDM (g-2) chiral changing Muon EDM The Muon Trio: B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
MEG MECO PRIME B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Today with e+e- based theory: All E821 results were obtained with a “blind” analysis. world average B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Electric and Magnetic Dipole Moments Transformation properties: An EDM implies both PandT are violated. An EDM at a measureable level would imply non-standard model CP. The baryon/antibaryon asymmetry in the universe, needs new sources of CP. B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Present EDM Limits *projected B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
General Statements • We know that n oscillate • neutral lepton flavor violation • Expect Charged lepton flavor violation at some level • enhanced if there is new dynamics at the TeV scale • in particular if there is SUSY • We expect CP in the lepton sector (EDMs as well as n oscillations) • possible connection with cosmology (leptogenesis) B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
The Physics Case: • Scenario 1 • LHC finds SUSY • MEG sees m→ e g • The trio will have SUSY enhancements • to understand the nature of the SUSY space we need to get all the information possible to understand the nature of this new theory B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
10 -11 10 -13 10 -15 10 -17 10 -19 10 -21 SUSY predictions ofm-A e-A From Barbieri,Hall, Hisano … Rme MECO single event sensitivity PRIME single event sensitivity 100 200 300 100 200 300 • eg& m-A e-ABranching Ratios are linearly correlated Complementary measurements(discrimination between SUSY models) B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Experimental bound Connection with n oscillations Additional contributiontoslepton mixingfromV21, matrix element responsible for solar neutrino deficit. (J. Hisano & N. Nomura, Phys. Rev. D59 (1999) 116005). tan(b) = 30 tan(b) = 0 Largely favoured and confirmed by Kamland After Kamland MEG goal All solar n experiments combined B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
SUSY connection between am , Dμ, μ→ e B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
aμ sensitivity to SUSY (large tanb) B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
SUSY, dark matter, (g-2) DE821 CMSSM B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
DE969 = Dnow B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
DE969= 0 B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
The Physics Case • Scenario 2 • LHC finds Standard Model Higgs at a reasonable mass, nothing else, (g-2) discrepancy could be the only indication beyond neutrino mass of New Physics • Then precision measurements come to the forefront, since they are sensitive to heavier virtual particles. • μ-e conversion is especially sensitive to other new physics besides SUSY B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Sensitivity to Various me Conversion Mechanisms Supersymmetry Compositeness Predictions at 10-15 Second Higgs doublet Heavy Neutrinos Heavy Z’, Anomalous Z coupling Leptoquarks After W. Marciano B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
The Experiments: LFV • μe conversion and Muonium-anti-Muonium conversion • pulsed beam • μ→ eg and eee • DC beam B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Near Term Experiments on LFV • MEG @ PSI (under construction, data begins in 2006) • 10-13 BR sensitivity • MECO @BNL (funding not certain) • 10-17 BR sensitivity B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
MEG @ PSI (10-13 BR sensitivity) Discovery Potential: 4 Events BR = 2 X 10-13 B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
The MECO Apparatus Straw Tracker Muon Stopping Target Muon Beam Stop Superconducting Transport Solenoid (2.5 T – 2.1 T) Crystal Calorimeter Superconducting Detector Solenoid (2.0 T – 1.0 T) Superconducting Production Solenoid (5.0 T – 2.5 T) Collimators approved but not funded 10-17BR single event sensitivity p beam B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Future Experiments on LFV • PRIME-type experiment • with FFAG muon storage ring • few X 10-19 • Such an experiment is perfect for the front end of a muon factory B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
m +e-→ m -e+ Full M search Muonium production B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
An improvement of 102 on GMM would confront these types of models which would also contribute to double b – decay. At the front end of a n factory with a pulsed beam this might be possible. B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Future Muon (g-2) Experiments • E969 @ BNL 0.5 → 0.20 ppm (scientific approval but not funded) • expected near-term improvement in theory, → the ability to confront the SM by ~ x 2 • The next generation 0.20 → 0.06 ppm • substantial R&D would be necessary • new ring or improved present ring? B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Use an E field for vertical focusing 0 spin difference frequency = ws - wc B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Muon (g-2): Store m ± in a storage ring magnetic field averaged over azumuth in the storage ring B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
E969: Systematic Error Goal • Field improvements will involve better trolley calibrations, better tracking of the field with time, temperature stability of room, improvements in the hardware • Precession improvements will involve new scraping scheme, lower thresholds, more complete digitization periods, better energy calibration B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
SM value dominated by hadronic issues: • Lowest order hadronic contribution ( ~ 60 ppm) • Hadronic light-by-light contribution ( ~ 1 ppm) The error on these two contributions will ultimately limit the interpretation of a more precise muon (g-2) measurement. B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
A (g-2) experiment to ~0.06 ppm? • Makes sense if the theory can be improved to 0.1 ppm, which is hard, but maybe not impossible. • With the present storage ring, we already have B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Where we came from: B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Today with e+e- based theory: All E821 results were obtained with a “blind” analysis. world average B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Muon EDM • Present limit ~10-19 e-cm • Could reach 10-24 to 10-25 at a high intensity muon source? B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Spin Precession Frequencies: m in B field with both an MDM and EDM The motional E - field, β X B, is much stronger than laboratory electric fields . ~GV/m with no sparks! The EDM causes the spin to precess out of plane. B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
EDM – up/down Asymmetry • avoid the magic γ and use a radial E-field to turn off (g-2) precession • Place detectors above and below the vacuum chamber and look for an up/down asymmetry which builds up with time B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Up/Down asymmetry vs. time time B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
The EDM ring • run with both μ+ and μ-. • there must be regions of combined E+B along with separate focusing elements. • There needs to be a scheme to inject CW and CCW. Possible Muon EDM Ring Parameters B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
A possible lattice Yuri Orlov B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
NP2 • the figure of merit is Nμ times the polarization. • we need to reach the 10-24 e-cm level. Narrow pulsed beam every ~100 ms B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Additional topics: • Muons for condensed matter (m SR) • Muon catalyzed fusion (m CF) • Muon lifetime (GF) • Muon capture (gp) • . . . B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Depth dependent mSR measurements in near surface regions B(z) Superconductor l z 0 • Magnetic field profile B(z) over nm scale • Characteristic lengths of the sc l, x B(z) B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
k0 90 Magnetic Field Profile in YBa2Cu3O7-d • Direct, absolute measurement of magnetic penetration depth • effective mass • density of supercarriers • Direct test of theories (London, BCS) local response exponential profile T.J. Jackson, T.M. Riseman, E.M. Forgan, H. Glückler, T. Prokscha, E. Morenzoni, M. Pleines, Ch. Niedermayer, G. Schatz, H. Luetkens, and J. Litterst, Phys. Rev. Lett. 84, 4958 (2000). B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Beams needed: • Pulsed intense muon beams • energy from surface (28 MeV/c) to 3.1 Gev/c • A few experiments could used DC beam, but almost all can use the pulse structure of a pulse, and some ms with no beam B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Beam requirements: A few examples B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Plans for next year • LFV experiments will continue to develop the techniques needed for these challenging experiments • Muon EDM collaboration will continue to investigate the appropriate ring structure. • Participate in scoping study for n factory • At present muon physics is not mentioned in the document of 10 June 2005 B. Lee Roberts, on behalf of the Intense Muon Physics Working Group
Summary • The questions addressed are at the center of the field of particle physics • There is an important program of muon physics which will be possible at the front-end of a n factory. • It makes use of the very intense flux which will be available there • If such a muon facility exists, there will also be a program of other very interesting muon experiments which is possible. B. Lee Roberts, on behalf of the Intense Muon Physics Working Group