1. 12 GeV MOLLER U PDATE TO THE H ALL A C OLLABORATION Juliette M. Mammei

2. O UTLINE Physics motivation Description of the experiment Update on spectrometer design (since Magnet Advisory Meeting) Status and Future Plans 2 Hall A Summer 2011 Collaboration Meeting

3. PV M OLLER SCATTERING 3 Hall A Summer 2011 Collaboration Meeting e- Z0Z0 12 GeV MOLLER A PV ≈ 35 ± 0.7 ppb A SEARCH FOR NEW PHYSICS

4. C OMPLEMENTARY TO THE LHC 4 Hall A Summer 2011 Collaboration Meeting Petriello et. al. (2009) 0.1% measurement of sin 2 θ W !

5. C OMPARISON TO Q WEAK MOLLER Qweak Target 150 cm, 5kW 35 cm, 2.5 kW Magnet 1550 A/cm 2 500 A/cm 2 Incident rate 20 GHz/sector 0.8 GHz/sector Asymmetry 35 ± 0.7 ppb 200 ± 5 ppb “Beam properties” ~0.2 ppb ~2 ppb 5 Hall A Summer 2011 Collaboration Meeting

6. E RROR B UDGET 6 Hall A Summer 2011 Collaboration Meeting o Dedicated measurements with auxiliary detectors Q2, transverse and inelastic asymmetries, pions o Careful design beam properties (1 st and 2 nd order – work at laser table) transverse (take advantage of cancellations) neutrals (design a “2-bounce” collimation system) o Improvements to polarimeters

7. T HE E XPERIMENT 7 Hall A Summer 2011 Collaboration Meeting two-toroid spectrometer (focus Møller electrons from 5.5-19 mrads) detectors located 28 m downstream (~150 GHz rate, <10% bkgd) 150 cm high power liquid hydrogen target 11 GeV, 75 μA beam Picture thanks to Patrick Rogan, UMass undergrad SOLIDWORKS STUDENT EDITION

8. 100% A ZIMUTHAL A CCEPTANCE 8 Hall A Summer 2011 Collaboration Meeting Forward Backward ForwardBackward e- COM Frame e- Lab Frame Identical particle scattering!

9. TOSCA 9 Hall A Summer 2011 Collaboration Meeting Use GEANT4 with a TOSCA- generated field map Use GEANT4 with a TOSCA- generated field map Commercial software available from Vector Fields for finite element analysis Tracking of particles with no radiative effects Magnetic Forces CAD-like capability Physical layout of coils Support structure Export to step file

10. C ONDUCTOR L AYOUT 10 Hall A Summer 2011 Collaboration Meeting Biot-Savart calculation optimized current returns Actual conductor layout

11. T RACKING IN TOSCA 11 Hall A Summer 2011 Collaboration Meeting

12. GEANT4 R ESULTS (O RIGINAL P ROPOSAL M ODEL ) 12 Hall A Summer 2011 Collaboration Meeting Radius (m) ϕ (degrees) θ lab (degrees) θ cm (degrees)

13. 13 Hall A Summer 2011 Collaboration Meeting GEANT4 R ESULTS (TOSCA M ODEL – ACTUAL C ONDUCTOR L AYOUT ) Radius (m) ϕ (degrees) θ lab (degrees) θ cm (degrees)

14. 14 Hall A Summer 2011 Collaboration Meeting PropertyUpstreamHybridQweak Field Integral (T·m) 0.151.10.89 Total Power (kW) 407651340 Current per wire (A) 2983849500 Voltage per coil (V) 1928518 Current Density (A/cm 2 ) 12001550500 Wire cross section (ID: water hole, in) 0.229x0.229 (0.128) 0.229x0.229 (0.128) 2.3x1.5 (0.8) Weight of a coil (lbs) 445557600 Magnetic Forces (lbs) 100300027000 M AGNET S TATS

15. B ACKGROUNDS 15 Hall A Summer 2011 Collaboration Meeting Field Map Moller (GHz) Elastic ep (GHz) Inelastic ep (GHz) Background (%) Proposal133120.49 TOSCA155140.58 Other sources of background include: scattering from aluminum target windows multiple-bounce photons (minimize 1-bounce) neutrons weak decays with large analyzing power To be studied with GEANT4 simulation!

16. S TATUS AND F UTURE P LANS Plan to do 3 runs: 14 PAC days – Achieve statistical precision of E158 95 PAC days – Focus on systematics, 25% statistical 235 PAC days – All the kinks ironed out FY 2011 MIE proposal to be submitted to DOE DNP by end of June (start of CD process) FY 2012-13 Complete design and engineering FY 2014-16 Construction funding 2016 Assembly in Hall for first run, ~3 months (commissioning + 14 PAC days) 16 Hall A Summer 2011 Collaboration Meeting

17. E XTRA S LIDES 17 Hall A Summer 2011 Collaboration Meeting

18. S UPPORT S TRUCTURE 18 Hall A Summer 2011 Collaboration Meeting 3.6 m 7 m

19. J EFFERSON L AB 19 Hall A Summer 2011 Collaboration Meeting Parity quality beam >85% using strained GaAs photocathodes Upgrade to 12 GeV beam energy, addition of a new Hall “D” 12 GeV MOLLER will run in Hall A with an 11 GeV, 75 μA beam 150 cm high power liquid hydrogen target detectors located 28 m downstream (~150 GHz rate, <10% bkgd) two-toroid spectrometer (focus Møller electrons from 5.5-19 mrads) Picture thanks to Patrick Rogan, UMass undergrad SOLIDWORKS STUDENT EDITION

20. T WEAKING THE OPTICS 20 Hall A Summer 2011 Collaboration Meeting Moller (ee) Mott (ep) Beam (centered at x=0, y=0)

21. 100% A ZIMUTHAL A CCEPTANCE 21 Hall A Summer 2011 Collaboration Meeting Forward Backward ForwardBackward e- COM Frame e- Lab Frame

22. S PIN P RECESSION AT J EFFERSON L AB 22 Hall A Summer 2011 Collaboration Meeting

23. E RROR B UDGET 23 Hall A Summer 2011 Collaboration Meeting Simulation, dedicated tracking detectors Careful work at laser table, cancellation with helicity reversal Compton/ Moller polarimeters Average over sectors, forward/backward cancellation Measurements of asymmetry between peaks Dedicated detectors

24. O UTLINE sin 2 θ W Interference of Z boson with single photon Moller scattering Comparable to 2 highest energy exp. Description of the 12 GeV MOLLER experiment apparatus High rate, small backgrounds – 150 GHz, 8% backgrounds Two toroids Novel toroid design (TOSCA and GEANT4) Angular acceptance 5.5-19 mrads 150cm target, detectors at 28m Multiple current returns High power 24 Hall A Summer 2011 Collaboration Meeting