A Parasitic search for a muon EDM to 10 -xx e -cm using tracking

1. A Parasitic search for a muon EDM to 10-xxe-cm using tracking Brendan Casey, Fermilab New (g-2)m Collaboration Meeting 3/19/2011

2. A universe with matter s d • Differences between matter and antimatter interactions allowed a small amount of matter to escape annihilation in the early universe • (4-6)x10-11 baryon to photon ratio • Observed CP violation in neutral meson mixing and decay only partially explains this • From CKM: < 6x10-27 baryons/photon • Huet, Sather PRD51 379 (1995) • New effects needed. A small permanent electric dipole moment (EDM) of elementary particles is a good candidate. • Violates P and T B. Casey, 3/19/2011

3. EDM expectations Large Bs CPV shrinks available parameter space • The large anomalous CPV in Bs mixing reported at the Tevatron + minimal flavor violation predicts EDMs are “around the corner!” • Gino Isidori, ICHEP 2010 plenary talk • Need lepton and quark EDM searches to distinguish new weak interaction from a small QQCD • Need different leptons to determine if the new phase is universal 10-25 Titanium 10-30 neutron Mercury Bs CPV Buras, Isidori, Paradisi arXiv:1007.5291 Muon may be the only competitive place we can study EDMs outside the first generation B. Casey, 3/19/2011

4. Muon EDM milestones 10-19 Phys. Rev. D 80, 052008 (2009) |dm|< 1.8 x 10-19 e-cm @ 95% 10-20 10-21 10-22 |dm|< 10-21 e-cm 10-23 10-24 10-25 10-26 10-27 B. Casey, 3/19/2011

5. Muon EDM milestones Im am hm Re SM 10-19 Phys. Rev. D 80, 052008 (2009) |dm|< 1.8 x 10-19 e-cm @ 95% 10-20 |dm|< 10-21 e-cm 10-21 10-22 |dm|~3 x 10-22 e-cm 10-23 10-24 10-25 10-26 10-27 B. Casey, 3/19/2011

6. Muon EDM milestones 10-19 Phys. Rev. D 80, 052008 (2009) |dm|< 1.8 x 10-19 e-cm @ 95% 10-20 |dm|< 10-21 e-cm 10-21 |dm|~3 x 10-22 e-cm 10-22 10-23 |dm| < 10-24 e-cm: (mm / me)2 10-24 10-25 |dm| < 10-26 e-cm: (mm / me) 10-26 10-27 B. Casey, 3/19/2011

7. Experimental setup • Muon sees E field pointing into the ring • Muon EDM will tilt the precession plane • Results in an up-down asymmetry in the positron decay angle, 90° out of phase M. Sossong’s analysis note B. Casey, 3/19/2011

8. Proposed update • Previous measurement based on ~10 million reconstructed positron tracks • Tracking detectors in front of all calorimeter stations could reconstruct ~1011 tracks in the new experiment • Factor 100 reduction in limit Muon orbit Positron trajectory Tracking volume B. Casey, 8/10/2010

9. Tracking design considerations Convoluted with Michelle Spectrum • Effective maximum asymmetry • Optimize design for positron momentum near 1.5 GeV • Inherent angular spread in decay angle • Sets upstream material budget: keep multiple scattering below this. • Occupancy throughout the fill • Sets how early we can take data • Many more details outlined in Thursday’s talk asymmetry ~11 mrad RMS inherent decay angle in positron decay B. Casey, 3/19/2011

10. Limit per POT We might have the statistics for 1 order of magnitude per 2 x 1020 POT |dm| x 1020 POT B. Casey, 3/19/2011

11. Tracking team Petersburg Nuclear Physics Institute Actively investigating cathode strip chambers, straws, and readout electronics options either inside the vacuum or using vacuum inserts Starting to investigate plastic scintillator and Silicon options as well Much more detail in Thursday’s detector team talk B. Casey, 3/19/2011

12. EDM conclusions • Best current knowledge indicates EDMs will be seen in experiments this decade • To understand what we see requires a measurement of the muon EDM • We know how to improve by (at least) 2 orders of magnitude by adding tracking stations to the new (g-2)m experiment • This naturally progresses into a dedicated muon EDM experiment at Project X B. Casey, 3/19/2011

13. Happy St. Patrick’s Day! Katie, Pono Dylan, Logan 3/17/2011 B. Casey, 3/19/2011