The Search for Exotic Sub-Millimeter Range Forces

Transcription

1 The Search for Exotic Sub-Millimeter Range Forces Classification, parameterization (short-range gravity experiments) Motivation and existing limits Experimental challenges Spin-Dependent Experiments Josh Long Indiana University, Bloomington Experiments above 1 mm (torsion pendulums, high-frequency) Experiments below 1 mm (Casimir suppression) Outlook HISEBSM 2016 XII Rencontres du Vietnam, Quy Nhon, Vietnam 31 July-6 August 2016 IUPUI IUB Indiana University Collaborative Research Grant

2 Non-Newtonian gravity (sample) r m 1 m 2 mm 1 2 F G rˆ 2 r F ~ B, L, B L,... mm 1 2 F G rˆ 2 r G 8 T Equivalence Principle Tests Composition-dependence, < few % of F G Eötvös ( ) Dicke (1960s) Eöt-Wash (~1990-present) Tests of the Inverse Square Law Precision F G, null tests, large effects >> F G Long (1976) Newman ( ) Eöt-Wash (~1990-present) Tests of Lorentz Invariance Precision F G Muller, Chu (2008-) [1] 2 [1] K.-Y. Chung et al., PRD (2009)

3 Parameterization Yukawa Interaction m B V r G Power Law m m r r0 n r r 0 = experimental scale n1 V m 1 m 2 r m m r 1 2 r / r G 1e m=0 m=0 / c range m B = strength relative to gravity m 1 m 2 set limits on n for n = 2-5

4 Limits from 1 mm to 1 light year [1,2] Lake Laboratory Tower Earth- LAGEOS LAGEOS- Lunar Planetary LLR ( in m) [1] E. Fischbach and C. Talmadge, The Search for Non-Newtonian Gravity (Springer-Verlag, 1999) [2] S. Reynaud and M.-T. Jaekel, Int. J. Mod. Phys. A (2005) 4

5 Short Range limits mass coupled Experimental limits: Irvine, HUST, Eot-Wash, = torsion pendulum experiments Stanford, IUPUI: MEMS-type experiment Torsion Osc: JCL et al., Nature (2003) Irvine: J. Hoskins et al., PRD (1985) HUST: W.-H. Tan et al., PRL (2016) Eot-Wash: D. Kapner et al., PRL (2007) Stanford: A. Geraci et al., PRD (2008) Casimir: Y.-J. Chen et al., PRL (2016)

6 Short Range Limits and Predictions Experimental limits: Irvine, HUST, Eot-Wash, = torsion pendulum experiments Stanford, IUPUI: MEMS-type experiment Limits still allow forces 1 million times stronger than gravity at 5 microns Theoretical predictions: Large extra dimensions Torsion Osc: JCL et al., Nature (2003) Irvine: J. Hoskins et al., PRD (1985) HUST: W.-H. Tan et al., PRL (2016) Eot-Wash: D. Kapner et al., PRL (2007) Stanford: A. Geraci et al., PRD (2008) Casimir: Y.-J. Chen et al., PRL (2016) Vacuum energy: prediction from new field which also keeps cosmological constant small Moduli, dilatons: new particles motivated by string models Theory: S. Dimopoulos, A. Geraci, PRD (2003)

7 Large Extra Dimensions compact dimension R Strong, Weak, EM force confined to 3 dimensions Gravity spreads out into n extra dimensions of size R, appears diluted R M M P * 2 / n 2 M * Gravity unifies with EW force (M* ~ 1 TeV) if n = 2, R ~ 1 mm n = 3, R ~ 1 nm N. Arkani-Hamed, S. Dimopoulos, G. Dvali, Phys. Lett. B (1998)

8 Challenge: scaling and backgrounds m 1, r 1 m 2, r 2 ~ 2r 3 2 Gm1 m2 Grr 1 2(4 r ) F ~ Grr r (2 r) 4r r 1 = r 2 = 20 g/cm 3, r = 10 cm F 10-5 N r = 100 mm F N 4 Electrostatic: F E ~ 0 V 2 r 2 Magnetic (contaminant): [ 3( ˆ)( rˆ)] m0 m1 m2 m1 r m2 F M ~ r 4 Casimir: F C ~ ħc r 4 8

9 Eot-Wash Torsion Pendulum Experiment D. Kapner, E. Adelberger et al., PRL (2007) tungsten fiber Torque and residuals vs. gap mirror for optical readout detector mass (Mo) source mass disks (Mo, Ta) 55 mm minimum gap 10 mm BeCu membrane (not shown) Limits: Scenarios with 1 excluded at 95% CL for 56 mm Largest extra dimension: R < 44 mm ADD Model (2 equal-sized extra dimensions compactified on a torus): R < 56 mm M* 3.2 TeV test mass flatness

10 Experimental Approach Planar Geometry - null for 1/r 2 Resonant detector with source mass driven on resonance 1 khz operational frequency - simple, stiff vibration isolation Double-rectangular torsional detector: high Q, low thermal noise Stiff conducting shield for background suppression ~ 5 cm Source and Detector Oscillators Shield for Background Suppression

11 Vibration isolation stacks: Brass disks connected by fine wires; soft springs which attenuate at ~10 10 at 1 khz (reason for using 1 khz) Central Apparatus vibration isolation stacks Scale: 1 cm 3 tilt stage Readout: capacitive transducer and lock-in amplifier referenced by source drive frequency shield transducer amp box detector mass PZT bimorph source mass Vacuum system: 10-7 torr Figure: Bryan Christie ( for Scientific American (August 2000)

12 Interaction Region source mass (retracted) 10 mm stretched Cu membrane shield (shorter ranges possible) detector mass front rectangle (retracted) Thinner shield 60 mm thick sapphire plate replaced by 10 mm stretched copper membrane Compliance ~5x better than needed to suppress estimated electrostatic force Minimum gap reduced from 105 mm (2003) to 40 mm.

13 Central Apparatus Inverted micrometer stages for full XYZ positioning ~50 cm Vacuum system base plate Torque rods for micrometer stage control

14 Sensitivity: increase Q and statistics, decrease T Signal Force on detector due to Yukawa interaction with source: F Y ( t) 2 2Gr r A exp( d( t)/ )[1 exp( t s d d s / )][1 exp( t d / )] ~ 3 x N rms (for = 1, = 50 mm) Thermal Noise 4kTD F T D m Q ~ 3 x N rms (300 K, Q = 5 x10 4, 1 day average) ~ 7 x N rms (4 K, Q = 5 x10 5, 1 day average)

15 Force Measurement Data March hours on-resonance data collected over 3 days with interleaved diagnostic data On Resonance Off Resonance On-resonance: Detector thermal motion and amplifier noise Off-resonance: amplifier noise

16 Current Limits (2s) and Projected Sensitivity 2012 gap ~ 100 microns; need flatter, more level elements Projected: 1 day integration time, 50 micron gap, 4.2 K, factor 50 Q improvement

17 Small gaps < P Casimir Bkgd. (Other ideas ) Intermediate Range P < < 10 mm Shield Casimir Background? Large gaps > 10 mm (Electrostatic Background) 3 c 0 Neutron: q = 0, Casimir-polder: UC 4 8 l Electric polarizability of atoms: 0 ~ cm 3 ; neutrons: 0 ~ cm 3 n-scattering: Y. Kamiya, et al., PRL (2015); V. Nesvizhevsky, G. Pignol, K. Protasov, PRD (2008)

18 Casimir Background Shielding Effect calculated using finite thickness corrections in: A. Lambrecht and S. Reynaud Eur. Phys. J. D 8 (2000) 309 Ideal for Yukawa forces with D > P

19 Indiana Purdue Casimir-less Experiment Y.-J. Chen, R. S. Decca, et al., Phys. Rev. Lett (2016) ~1 mm Force vs disk-sphere gap (each point ~ 50 min avg) electrodes oscillator Au coated sphere z rotation axis Si Au Rotating source disk Au coat not shown Points: sphere over alternating Au/Si strips Squares: over annular region with Au only (Signal: Casimir force from disk wobble)

20 Limits and Projections 1 µm 1 m R. Newman, Space Sci. Rev. 148 (2009) 175

21 Monopole-dipole [1] g s m 1 m φ iγ 5 g p m 2 Spin-Dependent Forces r/ S P ˆ s ˆ 2 8m 2 r r V r g g r e "V 9 + V 10 " [2] (P,T odd) g 1 g 2 = strength rel. to s ~1 1,2 = n,p,e Dipole-dipole iγ 5 g p m φ iγ 5 g p r/ P P ˆ 2 ( s1 ˆ s 2) ( ˆ 2 3 s1 ˆ)( ˆ s 2 ˆ) m2c r r r r r V r g g r r e m 1 m 2 "V 3 " Axion m-d [1]: 1 2 S P g g (60 MeV) m 2mm QCD 2 u d 2 2 FPQ ( mu md ) F PQ 2cm GeV [1] J. E. Moody and F. Wilczek, Phys. Rev. D 30, 130 (1984) [2] B. Dobrescu and I. Mocioiu, J. High Energy Phys. 0611, 005 (2006) 21

22 Spin-Dependent Forces [1] static spin-spin velocity dependent 72 independent couplings f i 1,2 monopole-dipole [1] B. Dobrescu and I. Mocioiu, J. High Energy Phys. 0611, 005 (2006)

23 Spin Dependent experiments (electron) N e / ˆ ˆ r S P s 2 8m 2 r r V r g g r e Eot-Wash ALP torsion pendulum astrophysical Astrophysical: g S N from torsion pendulums, g P e from white-dwarf cooling limits [2] S. Hoedl et al., PRL 106 (2011) Axion constraint from neutron EDM [3]: QCD = d n (e-cm) [2] G. Raffelt PRD 86, (2012) [3] R. J. Crewther, et al., Phys. Lett.91B, 487 (1980)

24 Spin Dependent experiments (electron) N e / ˆ ˆ r S P s 2 8m 2 r r V r g g r e Eot-Wash ALP torsion pendulum Compensated test mass (e.g., Dy 6 Fe 23 ) S. Hoedl et al., PRL 106 (2011)

25 Compensated Ferrimagnet m 1 T 0 m Total s Total m 2 T 1 < T 0 m 1 s Total m Total m 2 T C < T 1 m 1 m Total = 0 s Total m 2 Dy 6 Fe 23, ErFe 3, HoFe 3, Rare Earth Iron Garnets

26 Dysprosium Iron Garnet E. Weisman, R. Khatiwada Dy 3 Fe 5 O 12 Dy 3 Fe 5 O 12 recipe [1] 1. Add H 2 O to Dy(NO 3 ) 3 H 2 O powder for a 1M solution 2. Combine with 1M H 2 O and FeCl 3 6H 2 O solution 3. Add drops of base NaOH to precipitate rust colored solid DyIG powder G. Dionne, Magnetic Oxides (N.Y., Springer, 2009) DyIG pressed pellets (suitable for experiment) 4. Dry and press into pellet 5. Fire at 900C - color changes to olive green 6. Grind and fire again to increase purity [1] M. Gesselbracht, et al., J. Chem. Educ 71 (1994) mm x 1 mm

27 Projected sensitivity T. M. Leslie [1] [1] T. M. Leslie, E. Weisman, R. Khatiwada, JCL, PRD 89 (2014)

28 Beams near a wall velocity-dependent Projected Sensitivity to g 2 A PSI: F. Piegsa and G. Pignol, PRL (2012) A Monte Carlo estimation of sensitiv month of beam at LANSCE FP12 Apparatus LANL proposed: Courtesy W. M. Snow for the NSR collaboration Lack of polarized, nonmagnetic test masses (φ sensitivity in red) G. Vasilakis, M.V. Romalis et al., PRL (2009) 28

29 Static NMR near a mass axion search N n / ˆ ˆ r S P s 2 8m 2 r r V r g g r e Mainz: K. Tullney et al., PRL 111, (2013) Axion Resonant Interaction DetectioN Experiment (ARIADNE) [1] [1] A. Arvanitaki, A. Geraci, PRL 113, (2014)

30 Conclusions Dark matter Dark energy Unification models with extra dimensions extended symmetries Great interest in macroscopic forces with weak couplings to matter Macroscopic mass experiments: ~ 10 square decades of parameter space below 1 cm in past 10 years, continuing progress expected IU High-frequency experiment currently excludes spin-independent forces > 10 5 times gravitational strength above 10 microns Cryogenic experiment with gravitational sensitivity at 20 microns proposed Spin-dependent experiments: greater exclusion of parameter space below 1 cm in past 5 years, many new channels identified spin-dependent experiments with high frequency, NMR and other nuclear techniques unique sensitivity (or 8 orders of magnitude more than current experiments) to 15 interactions 30