Probing Relativity using Space-Based Experiments Fundamental Physics Research in Space International Workshop Washington DC 22-24 May 2006 Neil Russell Northern Michigan University, USA •The Standard-Model Extension (SME): a tool.
Download ReportTranscript Probing Relativity using Space-Based Experiments Fundamental Physics Research in Space International Workshop Washington DC 22-24 May 2006 Neil Russell Northern Michigan University, USA •The Standard-Model Extension (SME): a tool.
Probing Relativity using Space-Based Experiments Fundamental Physics Research in Space International Workshop Washington DC 22-24 May 2006 Neil Russell Northern Michigan University, USA •The Standard-Model Extension (SME): a tool to search for signals of quantum gravity at accessible energies •Clock-Comparison Tests •Optical and Microwave cavities Studying Quantum Gravity at sub-Planck Energies Energy Quantum Gravity EP Standard Model General Relativity Minkowski limit Curvature / torsion SM + GR highly successful description of observed phenomena These two field theories are expected to merge at the Planck scale 1019 GeV Suppressed effects of the fundamental quantum-gravity theory may be observable in sensitive experiments Relativity violation is a possible Planck-scale signal Any observable signals of Lorentz violation can be described using effective field theory Kostelecký, Potting PRD 51 3923 (1995) What should go into an effective QFT for Lorentz violation? Standard Model with Gravity Coordinate-independent Lorentz violation Standard-Model Extension “SME” SME contains • Minimally-coupled SM action • Pure-gravity action • Leading-order terms for Lorentz violation constructed from gravitational and SM fields Minimal SME: SME operators restricted to mass dimension 3 and 4 Kostelecký, PRD 69 105009 (2004) Colladay, Kostelecký, PRD 55 6760 (1997) PRD 58 116002 (1998) Special case: the Minimal SME • Neutral meson oscillations (*) • Neutrino oscillations • Clock-comparison tests – ground (*) • Clock-comparison tests -- space • Spin-polarized torsion pendulum (*) • Penning-trap tests of QED (*) • H (*) and anti H spectroscopy • Muon properties (*) • Cosmological birefringence (*) • Optical and microwave cavities (*) • Baryon asymmetry • Post-newtonian gravity New Scientist 16 August, 2003 The minimal SME has been used as the basis for a variety of investigations: (*) : bounds already existing There are now more than 500 papers on the SME http://physics.indiana.edu/ ~kostelec/faq.html Sidereal variations Kostelecký, PRL 80 1818 (1998) Clock-comparison tests Kostelecký, Lane, PRD 60, 116010 (1999) Bluhm, Kostelecký, Lane, Russell PRL 88, 090801 (2002) PRD 68, 125008 (2003) Clock-comparison tests frequency Line from atomic transition Stable clock 9.1 GHz time Lorentz-violation signal could occur as minuscule variation in clock frequency To detect signal, compare two clocks: one sensitive, one inert or differently affected sensitive inert Clock-comparison tests Accessing coefficients without suppression: Need change in z component of angular momentum Eg, for Hydrogen maser, 1,0 0,0 is suppressed, making a good reference clock; 1,1 1,0 is sensitive at leading order, making a good signal clock. To search for Lorentz and CPT violation in SME context, perturbation is… (Details of multiparticle aspects etc omitted) Kostelecký, Lane, PRD 60, 116010 (1999) Summary of SME bounds from Clock-comparison experiments minus log (bound/GeV) species neutron Hughes et al PRL 1960 Drever Phil Mag 1961 Prestage et al PRL 1985 Be / H maser proton Comment electron 27, 25 Lamoreaux et al PRL 1986 Hg / Hg 29, 27, 26 Chupp et al PRL 1989 Ne / He 27 Berglund et al PRL 1995 Hg / Cs 30, 28 Bear et al PRL 2000 He / Xe maser D. Phillips et al PRD 2001 H / H maser Cane et al PRL 2004 He / Xe maser Wolf et al PRL 2006 Cs fountain Analyzed in SME context by Kostelecky and Lane, PRD 1999 27, 25 27, 22 31 27 27 first boost bound 25, 22, 21 Possible advantages of space include: • greater boosts • greater fountain free-fall time • choice of orbital plane c tilde parameter Boosted clocks Clock-comparison analyses considering rotational effects: Kostelecký,Lane PRD 60 116010 (1999) Can consider also boosted trajectories of clocks in space. Bluhm, Kostelecký, Lane, Russell, PRL 2002 & PRD 2003 Issues: 1. A changing velocity is useful for improved sensitivity satellite in orbit is a good candidate 2. A standard inertial reference frame must be selected Good candidates are centered on the Sun, the galaxy, and the CMB. Earth-centered frame is not suitable. Choose Sun-centered frame, T starting at vernal equinox in 2000 Laboratory choices Wanted: fast-moving, rotating laboratory Speed v/c period ground 0.4 km/s (wrt Earth) 10-6 24 h ISS 8 km/s (wrt Earth) 10-5 92 min Earth 30 km/s (wrt Sun) 10-4 365 d Sun 200 km/s (wrt galaxy) 10-3 Dedicated experiment 300 km/s (wrt Sun) 10-3 ~10 sec SpaceTime? Z Satellite orbit z w sT s Y a Equatorial plane X Spring equinox Bluhm, Kostelecký, Lane, Russell, PRL 88, 090801 (2002); PRD 68, 125008 (2003) Need the inertial-frame quantities in terms of the lab-frame quantities… Bluhm, Kostelecký, Lane, Russell, PRL 88, 090801 (2002); PRD 68, 125008 (2003) General form of boost and rotation dependence for b3 tilde bs = speed of satellite relative to the Earth = 8 km/s b = speed of Earth relative to the Sun = 10 4 c = 30 km/s Without boosts, recover rotation dependence equivalent to result in Lane, Kostelecky PRD 1999 Optical and Microwave cavities Kostelecký and Mewes PRL 87, 251304 (2001) PRD 66, 056005 (2002) Lorentz-violating photon sector (dimensionless) Kostelecký and Mewes, PRL 87 251304 (2001); PRD 66 056005 (2002) 1 Parity even 3x3, traceless, symmetric Parity odd 5 5 5 3x3, antisymmetric 3 Total coefficients: 19 These 19 coefficients describe all dimensionless photon-sector observer-independent Lorentz violations SME Birefringence Tests The vacuum is found to be birefringent 10 relevant coefficients: 10 particular combinations: Comparison of polarization for different wavelengths Analysis based on data for 16 sources Kostelecký and Mewes, PRL 87 251304 (2001); PRD 66 056005 (2002) Cavity Oscillators Kostelecký and Mewes, PRL 87 251304 (2001); PRD 66 056005 (2002) Fractional frequency shifts for cavity optical: microwave, T010 cylindrical mode: Nˆ Tests with Optical and Microwave cavities Each experiment bounds different SME coefficient combinations Brillet,Hall (PRL 1979) Michelson-Morley type 1 combination of coeffs < 10-15 Hils,Hall (PRL 1990) Kennedy-Thorndike type 1 comb. of coeffs < 10-13 Lipa et al. (PRL 90 060403, 2003) -9 4 combs. of coeffs <10-13 ; 5 comb. of coeffs <10 Müller, Herrmann, Braxmaier, Schiller, Peters, (PRL 91 020401, 2003) -11 4 combs. of kappa coeffs <10-15 ; 5 comb. of kappa coeffs <10 Müller, Herrmann, Saenz, Peters, Lämmerzahl , (PRD 68 116006, 2003) -12 2 combs. of electron coeffs <10-14 ;1 comb. of electron coeffs <10 Wolf, Tobar, et al, (GRG 36 2352, 2004); and (PRD 70 051902, 2004) combs. of kappa coefficients <10-15 Müller, (PRD 71 045004, 2005) kappa coeffs <10-15 ; electron coeffs <10 Stanwix, Tobar, Wolf et al (PRL 95 040404, 2005) kappa e minus, ZZ component: 5.7 < 10-14 ; … 2.2 < 10-14 ; … Antonini, Okhapin, Göklü , Schiller (PRA 72 66102, 2005) 5.2 < 10-15 ; … Herrmann, Peters et al, (PRL 95 150401, 2005) -16 Planned or proposed space tests include: “SuperSUMO” Lipa, Wang, Nissen, Kasevich, Mester : (see poster) possible in principle to resolve c/c at 10–20 STEP orbiter platform (for example) ACES Cs Atomic clock (PHARAO) and space H maser (SHM) see talk by C. Salomon OPTIS Optical cavities and atomic clocks photon and fermion sectors of SME See talk by Laemmerzahl, poster by H. Dittus SpaceTime three ion clocks, trajectory close to Sun higher boost factor than Earth satellites see talk by Maleki PARCS PARCS Primary atomic reference clock in space, on ISS RACE Rubidium atomic clock experiment on ISS SUMO Superconducting microwave oscillator on ISS Gravitational tests : see talk by Kostelecky Examples: ACES, PARCS, RACE: Cesium and Rubidium Transition changes the z component of angular momentum eg: 4,4 4,3 For sensitivity of 100 Hz, bounded terms include: Proton and electron parameters: ~ GeV on bZ ~ -25 10 GeV on dZ ~ ~ ~ ~ ~ -23 10 GeV on bT, d±, dQ, dJK, HJT 10-27 Proton parameters: 10-25 GeV on c~Q from single and double frequencies Hydrogen maser Hyperfine transition: 1,1 1,0 Estimate, using 400 Hz variation limit: Proton and electron parameters: ~ 10-27 GeV on bZ ~ ~ ~ ~ ~ 10-23 GeV on bT, d±, dQ, dJK, HJT Summary The Standard-Model Extension (SME) • Allows study of all possible Lorentz violations in context of Standard Model and General Relativity • Limit of underlying Quantum-Gravity models The SME predicts • signals at the orbital and double-orbital frequencies • signals at the frequency of the Earth’s orbital motion Specific calculations for Cs 133, Rb 87, and H clocks are available and include relativistic effects at first order in the boost Estimates for attainable sensitivities for space have been obtained 10 of the 19 dimensionless photon coefficients are strongly constrained by birefringence The remaining ones have been vigorously pursued in cavity experiments; space tests hold the potential for even higher resolutions