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A spooky peek in the mirror: probing the weak nuclear force Christopher Crawford, University of Kentucky University of Kentucky Nuclear Physics Seminar Lexington, 2013-10-31

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The Halloween Interaction (HWI) 2013-10-31Nuclear Physics Seminar, University of Kentucky2/27 Trick or Treat Diagram

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The Halloween Interaction (HWI) 2013-10-31Nuclear Physics Seminar, University of Kentucky3/27 Trick or Treat Diagram

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The Halloween Interaction (HWI) 2013-10-31Nuclear Physics Seminar, University of Kentucky4/27 Trick or Treat Diagram

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2013-10-31 Nuclear Physics Seminar, University of Kentucky 5/27

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Hadronic Weak Interaction in a nutshell Hadronic Nuclear EW Nuclear PV Few-body PV 2013-10-31Nuclear Physics Seminar, University of Kentucky6/27

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DDH Potential isospin range Desplanques, Donoghue, Holstein, Annals of Physics 124, 449 (1980) N N N N Meson exchange STRONG (PC) WEAK (PV) PV meson exchange 2013-10-31Nuclear Physics Seminar, University of Kentucky np A nD A n 3 He A p np n n pp A z p A z f -0.11 0.92-0.18-3.12-0.97-0.34 hr0hr0 -0.50-0.14-0. 23-0.32 0.080.14 hr1hr1 -0.001 0.100.027 0.11 0.080.05 h2h2 0.0012-0.25 0.03 h0h0 -0.16-0.13-0. 23-0.22-0.070.06 h1h1 -0.003-0.002 0.05 0.22 0.070.06 Adelberger, Haxton, A.R.N.P.S. 35, 501 (1985) 7/27

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Danilov parameters / EFT Elastic NN scattering at low energy (

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p-p and nuclei Anapole Existing HPV data p-p scat. 15, 45 MeV A z pp p- scat. 46 MeV A z pp p-p scat. 220 MeV A z pp n+p d+ circ. pol. P d n+p d+ asym. A d n- spin rot. d n /dz 18 Fasym. I =1 19 F, 41 K, 175 Lu, 181 Ta asym. 21 Ne (even-odd) 133 Cs, 205 Tl anapole moment GOAL resolve coupling constants from few-body PV experiments only Wasem, Phys. Rev. C 85 (2012) 022501 1st Lattice QCD result 2013-10-31Nuclear Physics Seminar, University of Kentucky9/27 NPDGamma

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Sensitivity matrix for few-body reactions Contribution: 1.15 0.087 1.55 -.002 -0.47

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Experimental Sensitivities 2013-10-31Nuclear Physics Seminar, University of Kentucky11/27 Courtesy: Jason Fry

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NPDGamma Collaboration R. Alarcon 1, R. Allen 18, L.P. Alonzi 3, E. Askanazi 3, S. Baeler 3, S. Balascuta 1, L. Barron-Palos 2, A. Barzilov 27, W. Berry 8, C. Blessinger 18, D. Blythe 1, D. Bowman 4, M. Bychkov 3, J. Calarco,R. Carlini 5, W. Chen 6, T. Chupp 7, C. Crawford 8, M. Dabaghyan 9, A. Danagoulian 10, M. Dawkins 11, D. Evans 3, J. Favela 2, N. Fomin 12, W. Fox 11, E. Frlez 3, S. Freedman 13, J. Fry 11, C. Fu 11, C. Garcia 2, T. Gentile 6, M. Gericke 14 C. Gillis 11, K Grammer 12, G. Greene 4,12, J Hamblen 26, C. Hayes 12, F. Hersman 9, T. Ino 15, E. Iverson 4, G. Jones 16, K. Latiful 8, K. Kraycraft 8, S. Kucuker 12, B. Lauss 17, Y. Li 30, W. Lee 18, M. Leuschner 11, W. Losowski 11, R. Mahurin 12, M. Maldonado-Velazquez 2, E. Martin 8, Y. Masuda 15, M. McCrea 14, J. Mei 11, G. Mitchell 19, S. Muto 15, H. Nann 11, I. Novikov 25, S. Page 14, D. Parsons 26, S. Penttila 4, D. Pocinic 3, D. Ramsay 14,20, A. Salas-Bacci 3, S. Santra 21, S. Schroeder 3, P.-N. Seo 22, E. Sharapov 23, M. Sharma 7, T. Smith 24, W. Snow 11, J. Stuart 26, Z. Tang 11, J. Thomison 18, T. Tong 18, J. Vanderwerp 11, S. Waldecker 26, W. Wilburn 10, W. Xu 30, V. Yuan 10, Y. Zhang 29 1 Arizona State University 2 Universidad Nacional Autonoma de Mexico 3 University of Virginia 4 Oak Ridge National Laboratory 5 Thomas Jefferson National Laboratory 6 National Institute of Standards and Technology 7 Univeristy of Michigan, Ann Arbor 8 University of Kentucky 9 University of New Hampshire 10 Los Alamos National Laboratory 11 Indiana University 12 University of Tennessee, Knoxville 13 University of California at Berkeley 14 University of Manitoba, Canada 15 High Energy Accelerator Research Organization (KEK), Japan 16 Hamilton College 17 Paul Scherer Institute, Switzerland 18 Spallation Neutron Source, ORNL 19 University of California at Davis 20 TRIUMF, Canada 21 Bhabha Atomic Research Center, India 22 Duke University 23 Joint Institute of Nuclear Research, Dubna, Russia 24 University of Dayton 25 Western Kentucky University 26 University of Tennessee at Chattanooga 27 Univeristy of Nevada at Los Vegas 28 University of California, Davis 29 Lanzhou University 30 Shanghai Institute of Applied Physics 2013-10-31Nuclear Physics Seminar, University of Kentucky12/27

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Experimental Layout Supermirror Polarizer Gamma Detectors LH 2 Target RF Spin Rotator Beam Monitors 2013-10-31Nuclear Physics Seminar, University of Kentucky13/27

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Experimental setup at the FnPB Supermirror polarizer FNPB guide CsI Detector Array Liquid H 2 Target H 2 Vent Line Beam Stop Magnetic Field Coils Magnetic Shielding H 2 Manifold Enclosure 2013-10-31Nuclear Physics Seminar, University of Kentucky14/27

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Spallation neutron source spallation sources: LANL, SNS pulsed -> TOF -> energy LH2 moderator: cold neutrons thermal equilibrium in ~30 interactions 2013-10-31Nuclear Physics Seminar, University of Kentucky15/27

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Neutron Flux at the SNS FnPB SNS TOF window 15 meV LH 2 threshold 2013-10-31Nuclear Physics Seminar, University of Kentucky16/27 Flux = 6.5x10 10 n/s/MW 2.5 < < 6.0

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Chopped & folded spectrum 2013-10-31Nuclear Physics Seminar, University of Kentucky17/27

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Measurement of Beam Flux and Profile 2013-10-31Nuclear Physics Seminar, University of Kentucky18/27

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Nuclear interaction: neutron optics Fermi potential: Optical potential: Index of refraction: 2013-10-31Nuclear Physics Seminar, University of Kentucky19/27

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FnPB supermirror polarizer Fe/Si on boron float glass, no Gd m = 3.0 critical angle n = 45 channels r = 9.6 m radius of curvature l = 40 cm length d = 0.3mm vane thickness T=25.8%transmission P=95.3%polarization N=2.2 10 10 n/soutput flux (chopped) simulations using McStas / ROOT ntuple S. Balascuta et al., Nucl. Instr. Meth. A671 137 (2012) 2013-10-31Nuclear Physics Seminar, University of Kentucky20/27

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Polarimetry 3 He spin filter 2013-10-31Nuclear Physics Seminar, University of Kentucky21/27

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Longitudinal RF spin rotator Resonant RF spin rotator, 1/t RF amplitude tuned to velocity of neutrons Affects spin only NOT velocity! (no static gradients) essential to reduce instrumental systematics spin sequence: cancels drift to 2nd order danger: must isolate fields from detector false asymmetries: additive & multiplicave holding field snsn B RF P. Neo-Seo, et al. Phys. Rev. ST Accel. Beams 11 084701 (2008) 2013-10-31Nuclear Physics Seminar, University of Kentucky22/27

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Neutron beam monitors Improvements: Larger beam cross section Wires electrodes instead of plate Reduced absorption and scattering of beam Reduced microphonic noise pickup Similar chamber being constructed for n- 3 He exp. Purpose: Neutron Flux monitor Neutron Polarimetry (in conjunction with 3 He analyzer) Monitor ortho/para ratio in the target 2013-10-31Nuclear Physics Seminar, University of Kentucky23/27

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16L liquid para-hydrogen target 15 meV ortho para capture E n (meV) (b) 30 cm long 1 interaction length 99.97% para 1% depolarization Improvements: pressure-stamped vessel thinner windows p p p p para-H 2 p p p p ortho-H 2 E = 15 meV 2013-10-31Nuclear Physics Seminar, University of Kentucky24/27

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Ortho vs. Para H 2 neutron scattering L. Barron-Palos et al., Nucl. Instr. Meth. A671 137 (2012) Simulation by Kyle Grammer 2013-10-31Nuclear Physics Seminar, University of Kentucky25/27

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Installation of the LH 2 target in the FnPB Target Commissioned December 2011 2013-10-31Nuclear Physics Seminar, University of Kentucky26/27

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CsI(Tl) Detector Array 4 rings of 12 detectors each 15 x 15 x 15 cm 3 each VPDs insensitive to B field detection efficiency: 95% current-mode operation 5 x 10 7 gammas/pulse counting statistics limited 2013-10-31Nuclear Physics Seminar, University of Kentucky27/27

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Background Sub. & Geometry Factors 2013-10-31Nuclear Physics Seminar, University of Kentucky28/27 UP-DOWNLEFT-RIGHT neutron pol. RFSF eff. target depol. Aluminum background Aluminum asymmetry

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Chlorine PV asymmetry 2013-10-31Nuclear Physics Seminar, University of Kentucky29/27 Data set 40 hr. over 4 run periods Corrections Background Subtraction Beam Polarization Beam Depolarization RFSF Efficiency Geometric factors (1% uncertainty)

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Aluminum Asymmetry Dominant systematic effect 1525% background at SNS Extracted from decay amplitude Lifetime = 27 min Must measure A = 3 x 10 -8 PRELIMINARY 2013-10-31Nuclear Physics Seminar, University of Kentucky30/27

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Recent Hydrogen Data Preliminary result: A UD = (-7.14 4.4) x 10 -8 A LR = (-0.91 4.3) x 10 -8 200 hr. of data from Fall 2012 2013-10-31Nuclear Physics Seminar, University of Kentucky31/27

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Systematic & Statistical Uncertainties 2013-10-31Nuclear Physics Seminar, University of Kentucky32/27

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n-3He Collaboration 2013-10-31Nuclear Physics Seminar, University of Kentucky33/27

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n- 3 He PV Asymmetry ~ k n very small for low-energy neutrons - essentially the same asym. - must discriminate between back-to-back proton-triton S(I): 4He J =0 + resonance sensitive to EFT coupling or DDH couplings ~10% I=1 contribution (Gerry Hale, qualitative) A ~ -13x10 -7 (M. Viviani, PISA) A ~ -14x10 -7 (Gudkov) mixing between 0 +, 0 - resonance Nave scaling of p-p scattering at 22.5 MeV: A ~ 5x10 -8 PV observables: 19.815 20.578 Tilley, Weller, Hale, Nucl. Phys. A541, 1 (1992) n n + n n p p p p n n p p n n + p p n n p p n n p p

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Theoretical calculations progress Gerry Hale (LANL) PC A y ( 90 ) = -1.7 +/- 0.3 x 10 -6 R matrix calculation of PC asymmetry, nuclear structure, and resonance properties Michele Viviani et al. (INFN Pisa)PV A = -(.248 .944)10 -7 full 4-body calculation of scattering wave function -Kohn variational method with hyperspherical functions -No parity mixing in this step: J = 0 +, 0 -, 1 +, 1 - -Tested against n- 3 He scattering lengths evaluation of weak matrix elements -In terms of DDH potential Viviani, Schiavilla, Girlanda, Kievsky, Marcucci, PRC 82, 044001 (2010) Girlanda, Kievsky, Marcucci, Pastore, Schiavilla, Viviani, PRL 105 232502 (2010) Vladimir Gudkov (USC)PV A = -(1 4)10 -7 PV reaction theory Gudkov, PRC 82, 065502 (2010) Michele Viviani et al. (INFN Pisa)PV V NN EFT, a 0 a 5 Viviani, PAVI (2011), preliminary

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10 Gauss solenoid RF spin rotator 3 He target / ion chamber supermirror bender polarizer (transverse) FnPB cold neutron guide 3 He Beam Monitor FNPBn- 3 He Experimental setup at the FnPB longitudinal holding field suppressed PC nuclear asymmetry A=1.7x10 -6 (Hales) s n k n x k p suppressed by two small angles RF spin flipper negligible spin-dependence of neutron velocity 3 He ion chamber both target and detector 2013-06-06Seminar, Institut Laue Langevin36/48

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Transverse RF spin rotator Resonant RF spin rotator P-N Seo et al., Phys. Rev. S.T. Accel. Beam 11, 084701 (2008) Properties suitable for n- 3 He expt. Transverse horizontal RF B-field Longitudinal or transverse flipping No fringe field - 100% efficiency Real, not eddy currents along outside minimizes RF leaked outside SR Doesnt affect neutron velocity Compact geometry Matched to the driver electronics of the NPDGamma spin flipper Construction Development in parallel with similar design for nEDM neutron guide field Few-winding prototype built at UKy; Production RFSF being built now field lines end cap windings NPDGamma windings n- 3 He windings

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Inner / outer coil design Windings calculated using scalar potential Uniform transverse RF field inside Zero leakage field enforced by B.C.s Copper wires run along equipotentials 1.Inner region: 2.Intermediate: 3.Outer region: 4:1 inside / outside winding ratio By choosing appropriate radii Perfect cos theta windings inside & out 48 inner loops of 18 AWG wire

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Target Chamber Chamber design finished in 2010 delivered to U. of Manitoba, Fall 2010 All aluminum except for the knife edges. 4 feedthrough ports (200 readout channels) 2 HV ports + 2 gas inlets/outlets 12 inch Conflat aluminum windows (0.9 mm thick).

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Frame Design and Construction Chamber frame design finished in 2012 Received 50 Macor wire frames (up to 25 signal and 25 HV) $30K Final feature machining planned for early this year at UT shop. Platinum-Gold thick film wire solder pads on Macor to be completed early this year by Hybrid Sources Inc..

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Frame Assembly and Signal Readout The frame mounting structure is designed pieces will be ordered in the spring Two options for frame mounting: Mount into exit flange with threaded rods Insert into existing exit window flange Signal readout via circuit board traces Single HV connections Guide wires to feedthroughs with PMT- inspired stand-offs and ceramic beads

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Asymmetry Measurement Statistics PV Physics asymmetry is extracted from weighted average of single-wire spin asymmetries Two Monte Carlo simulations: 1.a code based on GEANT4 2.a stand-alone code including wire correlations N = 1.5x10 10 n/s flux (chopped) x 10 7 s (116 days) P = 96.2%neutron polarization d = 6 detector inefficiency 15% measurement in 1 beam cycle (without contingency), assuming A z = 1.15 x 10 -7

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Systematic Uncertainties Beam fluctuations, polarization, RFSF efficiency: k n r ~ 10 -5 small for cold neutrons PC asymmetries minimized with longitudinal polarization Alignment of field, beam, and chamber to 10 mrad is achievable Unlike n p -> d or n d -> t , n- 3 He is very insensitive to gammas (only Compton electrons) 2013-06-06Seminar, Institut Laue Langevin43/48

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Assembly in the FnPB cave 2013-06-06Seminar, Institut Laue Langevin44/48

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Commissioning / run plan 1.Scan beam profile upstream and transfer centroid to crosshairs 2.Scan beam profile downstream 3.Align theodolite to crosshairs 4.Align B-field to theodolite 5.Field map in RFSR/Target region 6.Align the position / angle of target with theodolite / autocollimator 7.Tune RSFR / measure polarization 8.Measure physics asymmetry 2013-06-06Seminar, Institut Laue Langevin45/48

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Conclusion Hadronic Parity Violation Is a complementary probe of nuclear and nucleonic structure A suite of at least four independent observables is needed to isolate the spin and isospin dependence With the five experiments: pp (45MeV), pp (220 MeV), NPDGamma, n-3He, NSR-III we can test the self-consistency of HWI formalisms NPDGamma Experiment Sensitive to long-range coupling f Statistics-limited experiment A = (-7.1 4.4) x 10 -8 Expect full data set by June 2014 Goal sensitivity: A = 1 x 10 -8 n- 3 He Experiment Last to characterize HWI 15% projected uncertainty most accurate few-body HWI experiment FnPB beam: June 2014 Dec 2015 NSR-III Experiment Gives us an over-constrained system of HWI observables 2013-10-31Nuclear Physics Seminar, University of Kentucky46/27

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Acknowledgements 2013-06-06Seminar, Institut Laue Langevin Yunchang Shin Elise Martin Daniel Wagner Binita Hona Andrew McNamara Michael Brown Aaron Sprow Kabir Latiful Chris Hayes Josh Henry Mary Estes Adam Ruff Haynes Wood Chris Menard Roel Flores Charles Fieseler Robert Milburn Jodie Lusby Kayla Craycraft Anna Butler William Berry Mario Fugal Justin Tomey Will Bates Edward Goodman Forrest Simmons Brad Irvin Alec Gilbert Dustin Doss Joseph Natter Deborah Ferguson Rebecca Schladt Mykalin Jones 47/48

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New Pi-coil Geometry Features: Flat surface supports and straight line windings Field lines kink at current-sheet interface between wedges Uniform flux density everywhere Crossovers in between wedges for automatic double-winding 2013-08-05Spin Rotation Collab Meeting48