Fundamental Physics Research in Space International Workshop Washington DC 22-24 May 2006 Probing Relativity using Space-Based Experiments Neil Russell.

Fundamental Physics Research in Space International WorkshopWashington DC22-24 May 2006

Probing Relativity using Space-Based Experiments

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

Standard Model General Relativity

Studying Quantum Gravity at sub-Planck Energies

SM + GR highly successful description of observed phenomena

What should go into an effective QFT for Lorentz violation?

These two field theories are expected to merge at the Planck scale 1019 GeV

Any observable signals of Lorentz violation can be described using effective field theory

Kostelecký, PottingPRD 51 3923 (1995)

Suppressed effects of the fundamental quantum-gravity theory may be observable in sensitive experiments

Relativity violation is a possible Planck-scale signal

Quantum GravityEP

Energy

Curvature / torsion Minkowski limit

Standard Model with Gravity Coordinate-independent Lorentz violation

Standard-Model Extension“SME”

Kostelecký, PRD 69 105009 (2004)Colladay, Kostelecký, PRD 55 6760 (1997)

PRD 58 116002 (1998)

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

Special case: the Minimal SME

The minimal SME has been used as the basis for a variety of investigations: (*) : bounds already existing

• 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

Sci

entis

t 16

Aug

ust,

2003

http://physics.indiana.edu/~kostelec/faq.html

There are now more than 500 papers on the SME

Sidereal variationsKostelecký, PRL 80 1818 (1998)

Clock-comparison tests

Kostelecký, Lane, PRD 60, 116010 (1999)

Bluhm, Kostelecký, Lane, RussellPRL 88, 090801 (2002) PRD 68, 125008 (2003)

Stable clock9.1 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

Line fromatomic transition

sensitive

inert

frequency

Clock-comparison tests

To search for Lorentz and CPT violation in SME context, perturbation is…

(Details of multiparticle aspects etc omitted)

Clock-comparison tests

Kostelecký, Lane, PRD 60, 116010 (1999)

Accessing coefficients without suppression: Need change in z component of angular momentumEg, for Hydrogen maser,

0,00,1 is suppressed, making a good reference clock;

0,11,1 is sensitive at leading order, making a good signal clock.

species Comment

neutron proton electron

Hughes et al PRL 1960

Drever Phil Mag 1961

Prestage et al PRL 1985 Be / H maser 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 27, 25 27, 22

Bear et al PRL 2000 He / Xe maser 31

D. Phillips et al PRD 2001 H / H maser 27

Cane et al PRL 2004 He / Xe maser 27 first boost bound

Wolf et al PRL 2006 Cs fountain 25, 22, 21 c tilde parameter

minus log (bound/GeV)

Analyzed in SME context by Kostelecky and Lane, PRD 1999

Summary of SME bounds from Clock-comparison experiments

Possible advantages of space include:

• greater boosts

• greater fountain free-fall time

• choice of orbital plane

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

Boosted clocks

Laboratory choices

Speed v/c period

ground0.4 km/s (wrt Earth)

10-6 24 h

ISS8 km/s(wrt Earth)

10-5 92 min

Earth30 km/s(wrt Sun)

10-4 365 d

Sun200 km/s (wrt galaxy)

10-3

Dedicated experiment

300 km/s(wrt Sun)

10-3 ~10 sec

Wanted: fast-moving, rotating laboratory

SpaceTime?

ss

X

Y

Z

Equatorial plane

Spring equinox

Satellite orbit

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)

s = speed of satellite relative to the Earth = 8 km/s

Without boosts, recover rotation dependence equivalent to result in Lane, Kostelecky PRD 1999

General form of boost and rotation dependence for b3 tilde

= speed of Earth relative to the Sun = 10 4 c = 30 km/s

Optical and Microwave cavities

Kostelecký and MewesPRL 87, 251304 (2001) PRD 66, 056005 (2002)

Lorentz-violating photon sector (dimensionless)

Parityodd

Parityeven

1

3x3,traceless,symmetric

3x3,antisymmetric

3

Total coefficients: 19

5

5

5

Kostelecký and Mewes, PRL 87 251304 (2001); PRD 66 056005 (2002)

These 19 coefficients describe all dimensionless photon-sector observer-independent Lorentz violations

SME Birefringence Tests

10 relevant coefficients:

The vacuum is found to be birefringent

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

optical:

microwave, T010 cylindrical mode:

Fractional frequency shifts for cavity

Kostelecký and Mewes, PRL 87 251304 (2001); PRD 66 056005 (2002)

N̂

Tests with Optical and Microwave cavities Each experiment bounds different SME coefficient combinations

Lipa et al. (PRL 90 060403, 2003)4 combs. of coeffs <10-13 ; 5 comb. of coeffs <10

-9

Brillet,Hall (PRL 1979) Michelson-Morley type1 combination of coeffs < 10-15

Hils,Hall (PRL 1990) Kennedy-Thorndike type 1 comb. of coeffs < 10-13

Müller, Herrmann, Braxmaier, Schiller, Peters, (PRL 91 020401, 2003)

4 combs. of kappa coeffs <10-15 ; 5 comb. of kappa coeffs <10-11

Müller, Herrmann, Saenz, Peters, Lämmerzahl , (PRD 68 116006, 2003)

2 combs. of electron coeffs <10-14 ;1 comb. of electron coeffs <10-12

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 <10-16

Herrmann, Peters et al, (PRL 95 150401, 2005) 5.2 < 10-15 ; …

Antonini, Okhapin, Göklü , Schiller (PRA 72 66102, 2005) 2.2 < 10-14 ; …

Stanwix, Tobar, Wolf et al (PRL 95 040404, 2005)

kappa e minus, ZZ component: 5.7 < 10-

14 ; …

“SuperSUMO”

Planned or proposed space tests include:

Lipa, Wang, Nissen, Kasevich, Mester : (see poster)possible in principle to resolve c/c at 10–20

STEP orbiter platform (for example)

OPTISOptical cavities and atomic clocks photon and fermion sectors of SME

See talk by Laemmerzahl, poster by H. Dittus

ACES

Cs Atomic clock (PHARAO) and space H maser (SHM) see talk by C. Salomon

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

Gravitational tests : see talk by Kostelecky

Rubidium atomic clock experiment on ISS

RACE

SUMO Superconducting microwave oscillator on ISS

Transition changes the z component of angular momentum eg: 4,4 4,3

Proton and electron parameters:

For sensitivity of 100 Hz, bounded terms include:

Proton parameters:

10-27 GeV on bZ

10-25 GeV on dZ

10-23 GeV on bT, d±, dQ, dJK, HJT

~~

~

~

~ ~ ~

10-25 GeV on cQ from single and double frequencies~

Hydrogen maser

10-27 GeV on bZ

10-23 GeV on bT, d±, dQ, dJK, HJT

~~ ~ ~ ~

~

Hyperfine transition: 1,1 1,0

Proton and electron parameters:

Estimate, using 400 Hz variation limit:

Cesium and Rubidium

Examples: ACES, PARCS, RACE:

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

Summary

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