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Juliette M. Mammei Virginia Tech for the Qweak Collaboration Funded by NSF, DOE, SURA,

Qweak: A Search for New Physics at the TeV Scale. Juliette M. Mammei Virginia Tech for the Qweak Collaboration Funded by NSF, DOE, SURA, NSFGRF, VT Cunningham. The Qweak Collaboration. D. Armstrong, T. Averett, J. Benesch, J. Birchall, P. Bosted, A. Bruell, C. Capuano,

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Juliette M. Mammei Virginia Tech for the Qweak Collaboration Funded by NSF, DOE, SURA,

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  1. Qweak: A Search for New Physicsat the TeV Scale Juliette M. Mammei Virginia Tech for the Qweak Collaboration Funded by NSF, DOE, SURA, NSFGRF, VT Cunningham Hall C Meeting January 2008

  2. The Qweak Collaboration D. Armstrong, T. Averett, J. Benesch, J. Birchall, P. Bosted, A. Bruell, C. Capuano, R. Carlini1 (Contact Person), G. Cates, S. Chattopadhyay, S. Covrig, CA Davis, K. Dow, J. Dunne, D. Dutta, R. Ent, J. Erler, W. Falk, JM Finn1, T. Forest, W. Franklin, D. Gaskell, J. Grames, M. Gericke, K. Grimm, FW Hersman, M. Holtrop, P. King, K. Johnston, R. Jones, K. Joo, C. Keppel, M. Khol, E. Korkmaz, S. Kowalski1, L. Lee, Y. Liang, A. Lung, D. Mack, S. Majewski, J. Mammei, R. Mammei, J. Martin, D. Meekins, H. Mkrtchyan, N. Morgan, K. Myers, A. Opper, SA Page1, J. Pan, K. Paschke, M. Pitt, B. (Matt) Poelker, T. Porcelli, Y. Prok, WD Ramsay, M. Ramsey-Musolf, J. Roche, N. Simicevic, G. Smith2, R. Suleiman, E. Tsentalovich, WTH van Oers, P. Wang, S. Wells, S. Wood, R. Young, H. Zhu, C. Zorn 1Co-pokespersons 2Project Manager California Institute of Technology, College of William and Mary, George Washington University, Hampton University, Idaho State University, Louisiana Tech University, Massachusetts Institute of Technology, Mississippi State University, Ohio University, Thomas Jefferson National Accelerator Facility, TRIUMF, University of Connecticut, University of Manitoba, University of Mexico, University of New Hampshire, University of Northern British Columbia, University of Virginia, University of Winnipeg, Virginia Polytechnic Institute & State University, Yerevan Physics Institute

  3. Weak Charges of Light Quarks EM Charge Weak Charge EM Charge Weak Charge Hall C Meeting January 2008

  4. +  + “Running” of sin2W • Electroweak radiative corrections •  sin2W varies with Q Standard Model Prediction Erler, Kurylov & Ramsey-Musolf, Phys. Rev. D 68, 016006 (2003) The “running” curve is normalized by measurements at the Z0 resonance. Hall C Meeting January 2008

  5. Hadronic Structure Contribution PDG SM theoretical estimates of anapole form factor Qpweak Young, Ross, et. al. PRL 99:122003,2007 Hall C Meeting January 2008

  6. Sensitivity to TeV Scale Erler et al., PRD68(2003) Data sets limits on Hall C Meeting January 2008

  7. Neutral Weak Effective Couplings Young, Ross, et. al. PRL 99:122003,2007 Hall C Meeting January 2008

  8. Limits on Extensions to the Standard Model Erler, Kurylov, Ramsey-Musolf, PRD 68, 016006 (2003) Hall C Meeting January 2008

  9. Experimental sensitivity: Precision measurement: Anticipated QpWeak Uncertainties  Aphys/AphysQpweak/Qpweak Statistical (2200 hours production) 2.1% 3.2% Systematic: Hadronic structure uncertainties -- 1.5% Beam polarimetry 1.0% 1.5% Absolute Q2 determination 0.5% 1.0% Backgrounds 0.5% 0.7% Helicity-correlated Beam Properties 0.5% 0.7% _________________________________________________________ Total 2.5% 4.1% Expected value: A(Q2=0.026 GeV2) = -0.234 ppm !!! Hall C Meeting January 2008

  10. Qweak 101 • Keep technology simple! • Build on JLab expertise with parity quality polarized beams (1.165 GeV) • Dual Moller and Compton polarimeters (85% polarized beam) • Resistive toroid magnet (particle separation - ~9000A) • Quartz cerenkov detectors in current mode: Rad hard (stable) and rejection of non-relativistic events Low gain PMTs operated in linear current integrating mode Precision 18-bit ADC rapid sampling (equivalent to 26 bit) • Counting mode (sub nA beam current) for Q2 calibration • World’s highest power LH2 cryogenic target (~2.5 kW) • Rapid flipping (125 Hz) of beam helicity (up to 500Hz) to suppress beam systematics and target boiling noise Hall C Meeting January 2008

  11. Experiment Component Status Main Detectors (Components at JLab) Target (Design) Downstream Pb Shielding (Complete) QTOR +Power Supply (Mapping soon - Bates) Collimators (Procurement) Lumis (Design) Lumis (Design) R-3 Rotation System (Fabrication) Beam New Quartz Scanner (Design) R-2 HDCs (Fabrication and testing) GEMs (Prototype + parts) R-3 VDC (Fabrication) Hall C Meeting January 2008

  12. Main Detectors View Along Beamline of QWeak Apparatus - Simulated Events 8 fused silica radiators (Spectrosil 2000) 200cm x 18cm x 1.25cm 5” PMTs (gain = 2000) Central scattering angle: ~8° ± 2° Phi Acceptance: ~50% of 2π Average Q²: 0.026 GeV2 Acceptance averaged asymmetry: –0.234 ppm Integrated Rate (per detector): ~810 MHz Inelastic/Elastic ratio: ~0.4% Very clean elastic separation! Hall C Meeting January 2008

  13. Main Detectors Quartz bar quality control Bars, light guides, PMTs, IV preamps delivered. Final testing of 18-bit ADC prototypes Gluing jig PMT gain vs. voltage Hall C Meeting January 2008

  14. Target Assembling the heat exchanger Target status Shakedown – with cold He gas Summer ‘08 Neon test – early 2009 High power test – Spring 2009 Beam Hall C Meeting January 2008

  15. Magnet Attaching a coil to the supports Assembled toroid with mapper 9500 A power supply delivered; Field mapping to begin in March Hall C Meeting January 2008

  16. Tracking system GEM prototype and rotator (LA Tech, Idaho State) Region III VDC and rotator (W&M) Region II HDC (VPI) Hall C Meeting January 2008

  17. Conclusion • DOE spending ¾ finished! • most systems are constructing and/or testing • on track to be ready in January ’09 • scheduled for Sept. or Nov. ’09 • ~6 months install, ~4 months commissioning, ~12 months running Hall C Meeting January 2008

  18. Extra Slides Hall C Meeting January 2008

  19. Experiment Status Hall C Meeting January 2008

  20. “DAQ” Tracking System If the track doesn’t point to the target, or if the kinematics don’t match an elastic event, then it is background GEMs – Gas Electron Multiplier HDCs – Horizontal Drift Chamber QTOR – Toroidal Magnet VDCs – Vertical Drift Chamber Region III VDCs Region II HDCs Region I GEMs QTOR Trigger Scintillator Hall C Meeting January 2008

  21. amplifier amplifier Readout PCB Readout PCB Collection Collection GEM 3 GEM 3 GEM 2 GEM 2 avalanche ~12mm avalanche ~12mm GEM 1 GEM 1 sense wire sense wire guard wire guard wire cathode cathode electron electron HDCs – Horizontal Drift Chamber VDCs – Vertical Drift Chamber GEMs – Gas Electron Multiplier Hall C Meeting January 2008

  22. TRIUMF Custom Low Noise Electronics Noise test on bench at TRIUMF VME integrator – 18 bit ADC sampling at 500 kHz FPGA sums 500 samples into one data word same resolution as a 26 bit ADC 2 ppb! Electronic noise is about 3 orders of magnitude below the counting statistics of electron tracks. This permits very sensitive checks with LED light sources and battery powered current sources in only one shift.

  23. Indirect search for new physics JLAB Qweak SLAC E158 • Qweak measurement will provide a stringent stand alone • constraint on Lepto-quark based extensions to the SM. • Qpweak (semi-leptonic) and E158 (pure leptonic) together • make a powerful program to search for and identify new • physics. Hall C Meeting January 2008

  24. Qpweak: Parity-Violating Electron Scattering Scatter longitudinally polarized electrons on unpolarized protons Interference gives rise to parity violating asymmetry MNC MEM Hall C Meeting January 2008

  25. Energy Scale of an “Indirect” Search for New Physics • Parameterize New Physics contributions in electron-quark Lagrangian g: coupling constant, : mass scale • A 4% QpWeak measurement probes with • 95% confidencelevel for new physics • at energy scales to: • If LHC uncovers new physics, then precision • low Q2 measurements will be needed to • determine charges, coupling constants, etc. Hall C Meeting January 2008

  26. In the case of a significant deviation from SM... Constraint including Qweak at central value of current measurements with Qweak with PVES atomic only If LHC finds a Z′, Qweak will help determine its properties Hall C Meeting January 2008 Analysis by Ross Young, JLab

  27. Running coupling constants in QED and QCD 137  s QED (running of ) QCD(running of s) Q2, GeV2 Hall C Meeting January 2008

  28. Why are Precision Measurements far Below the Z-pole Sensitive to New Physics? Precision measurements well below the Z-pole have more sensitivity (for a given experimental precision) to new types of tree level physics, such as additional heavier Z’ bosons. Hall C Meeting January 2008

  29. Relative Shifts in Proton and Electron Weak Charges due to SUSY Effects R parity (B-L conservation) RPC SUSY occurs only at loop level RPV SUSY occurs at tree level Erler, Ramsey-Musolf, Su hep-ph/0303026 Hall C Meeting January 2008

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