Hughes-Drever experiment

from Wikipedia, the free encyclopedia
7 Li- NMR spectrum of LiCl (1M) in D 2 O. The sharp, undivided NMR line of this lithium isotope is evidence of the isotropy of mass and energy.

Hughes-Drever experiments (also clock comparison, clock anisotropy, mass isotropy, or energy isotropy experiments) are used for the spectroscopic examination of the isotropy of mass or space. These experiments test fundamental statements of both special and general relativity . As with the Michelson-Morley experiments , the existence of a preferred reference system or deviations from the Lorentz invariance can be checked, which also affects the validity of the equivalence principle . In contrast to Michelson-Morley, Hughes-Drever experiments refer to the isotropy of the interactions with the matter itself, i.e. of protons , neutrons and electrons . The accuracy achieved in this way makes this type of experiment carried out up to now one of the most precise measurements of the theory of relativity at all (cf. tests of the special theory of relativity ).

Experiments by Hughes and Drever

Giuseppe Cocconi and Edwin Salpeter (1958) pointed out that the inertia of matter depends on the distribution of the surrounding masses if Mach's principle is correct. This would lead to anisotropy of inertia in different directions and could be demonstrated by spectroscopic observation of Zeeman effects in atomic nuclei .

Vernon Hughes et al . (1960) and Ronald Drever (1961) now carried out similar experiments independently of one another. The nucleus of lithium -7 was used, the ground state of which has a spin of 3 ⁄ 2 , and thus four magnetic energy levels will exist in a magnetic field in accordance with the permitted magnet quantum number . With mass isotropy there is no shift of the energy level and consequently only a single resonance line should exist, with anisotropy there is a triplet resonance line or a broadening. In fact, no frequency shift of the energy levels was found, although the maximum anisotropy could be limited to 0.04 Hz = 10 −25  GeV due to the great accuracy  .

Robert H. Dicke (1961) was able to show, however, that the zero result is entirely compatible with Mach's principle as long as the spatial anisotropy is the same for all particles. The zero result shows that the mass anisotropy effects, if they exist, are the same for all particles and consequently cannot be observed locally.

Modern interpretation

While this experiment was originally related to Mach's principle, it is often interpreted in modern papers as an important test of the Lorentz invariance and thus of the special theory of relativity. Because anisotropy effects must also be present in the presence of a preferred reference system (usually the CMB rest system as ether ), so the negative results of the Hughes-Drever experiment - like the Michelson-Morley experiments - can be viewed as refutations of the existence of such a system. In particular, the physicists Mark P. Haugan and Clifford Will were able to show that these experiments can be interpreted as verifications of the question whether the limit speed of matter corresponds to the speed of light, as required by the special theory of relativity. If they do not match, the properties and frequencies of the interactions of matter also change. And since it is a basic statement of the equivalence principle of general relativity that locally the Lorentz invariance is valid in freely falling frames of reference = Local Lorentz invariance (LLI), the results of this experiment concern both the special and the general relativity theory.

Due to the fact that different frequencies are compared here, and these in turn can be understood as clocks, these experiments are also referred to as "clock comparison" experiments.

Recent experiments

In addition to violations of the Lorentz invariance due to the presence of a preferred reference system or Mach's principle, in the course of the developments in quantum gravity , possible spontaneous refractions of the Lorentz invariance and the related CPT theorem have come into focus. To check all of these effects, ever more precise variations of the original experiments are carried out to this day. These measurements relate to neutrons and protons , and the use of spin-polarized systems and comagnetometers (which can suppress magnetic influences) significantly increased the accuracy. In addition, the electron sector is checked with the aid of spin-polarized torsion balances.

All results have been negative so far, so that there is still no indication of the existence of a preferred reference system or any other violation of the Lorentz invariance. The values ​​in the following table relate to the parameters that are specified by the standard model extension (SME, one of the test theories of the special theory of relativity ). This model contains various parameters for every deviation from the Lorentz invariance. Since a number of parameters are checked in each of these experiments, only the value of the maximum sensitivity is given here (for the exact list, see the individual articles):

author year SME limits description
proton neutron electron
Prestage et al. 1985 10 −27 The nuclear spin-flip transition of 9 Be + (stored in a Penning trap ) is compared to a hydrogen maser clock .
Phillips 1987 10 −27 Sinusoidal oscillations are examined using a cryogenic spin-torsion balance that carries a transversely polarized magnet.
Lamoreaux et al. 1989 10 −29 There are dipolar and quadrupolar spin polarizations in a 201 Hg induces gas, and looked for variations.
Chupp et al. 1989 10 −27 Research was carried out into time-dependent quadrupolar splitting of the Zeemann level . 21 Ne and 3 He gases are polarized by spin exchange and compared with one another.
Wineland et al. 1991 10 −25 Anomalous dipole-monopole and dipole-dipole couplings are investigated by exploring the hyperfine resonances in 9 Be + .
Wang et al. 1993 10 −27 A spin torsion balance, which carries a spin-polarized Dy 6 Fe 23 mass, is examined for sidereal variations.
Berglund et al. 1995 10 −27 10 −30 10 −27 The frequencies of 199 Hg and 133 Cs are compared using a magnetic field.
Bear et al. 2000 10 −31 The frequencies of 129 Xe and 3 He Zeeman masks are compared.
Phillips et al. 2000 10 −27 The Zeeman frequency is determined with a hydrogen maser.
Humphrey et al. 2003 10 −27 10 −27 See Phillips et al. (2000).
Hou et al. 2003 10 −29 See Wang et al. (1993).
Canè et al. 2004 10 −32 See Bear et al. (2000).
Wolf et al. 2006 10 −25 Atomic frequencies are measured using laser-cooled 133 Cs atomic fountains.
Heckel et al. 2006 10 −30 It was a spin-torsion balance used, consisting of four sections of Alnico and four sections of Sm 5 Co .
Heckel et al. 2008 10 −31 See Heckel et al. (2006).
Altarev et al. 2009 10 −29 The spin precession frequencies in stored ultra- cold neutrons and 199Hg are analyzed.
Brown et al. 2010 10 −32 10 −33 The frequencies in a K / 3 He comagnetometer are compared.
Gemmel et al. 2010 10 −32 The frequencies in a 129 Xe / 3 He comagnetometer are compared.
Smiciklas, et al. 2011 10 −29 The frequencies in a 21 Ne / Rb / K comagnetometer are compared. Test of the limit speed of neutrons.
Peck et al. 2012 10 −30 10 −31 Similar to Berglund et al. (1995).
Hohensee et al. 2013 10 −17 Measurements of the transition frequencies of two approximately degenerate states of 164 Dy and 162 Dy. Test of the limit speed of electrons.
Allmendinger et al. 2013 10 −34 See Gemmel et al. (2010).

Individual evidence

Overview literature:

  1. ↑ a b Will, CM: The Confrontation between General Relativity and Experiment . In: Living Reviews in Relativity . 9, No. 3, 2006. Retrieved June 23, 2011.
  2. ↑ a b Will, CM: Stable clocks and general relativity . In: Proceedings of the 30th Rencontres de Moriond . 1995, p. 417. arxiv : gr-qc / 9504017 .
  3. ↑ a b c Kostelecký, V. Alan; Lane, Charles D .: Constraints on Lorentz violation from clock-comparison experiments . In: Physical Review D . 60, No. 11, 1999, p. 116010. arxiv : hep-ph / 9908504 . doi : 10.1103 / PhysRevD.60.116010 .
  4. ^ A b c Mattingly, David: Modern Tests of Lorentz Invariance . In: Living Rev. Relativity . 8, No. 5, 2005.
  5. ↑ a b Pospelov, Maxim; Romalis, Michael: Lorentz Invariance on Trial . In: Physics Today . 57, No. 7, 2004, pp. 40-46. doi : 10.1063 / 1.1784301 .
  6. ^ A b Walsworth, RL: Tests of Lorentz Symmetry in the Spin-Coupling Sector . In: Lecture Notes in Physics . 702, 2006, pp. 493-505. doi : 10.1007 / 3-540-34523-X_18 .
  7. ↑ Hou, Li-Shing; Ni, Wei-Tou; Li, Yu-Chu M .: Test of Cosmic Spatial Isotropy for Polarized Electrons Using a Rotatable Torsion Balance . In: Physical Review Letters . 90, No. 20, 2003, p. 201101. arxiv : physics / 0009012 . doi : 10.1103 / PhysRevLett.90.201101 .

Sources for values:

  1. ↑ Cocconi, G .; Salpeter E .: A search for anisotropy of inertia . In: Il Nuovo Cimento . 10, No. 4, 1958, pp. 646-651. doi : 10.1007 / BF02859800 .
  2. ↑ Hughes, VW; Robinson, HG; Beltran-Lopez, V .: Upper Limit for the Anisotropy of Inertial Mass from Nuclear Resonance Experiments . In: Physical Review Letters . 4, No. 7, 1960, pp. 342-344. doi : 10.1103 / PhysRevLett.4.342 .
  3. ↑ Drever, RWP: A search for anisotropy of inertial mass using a free precession technique . In: Philosophical Magazine . 6, No. 65, 1961, pp. 683-687. doi : 10.1080 / 14786436108244418 .
  4. ↑ Dicke, RH: Experimental Tests of Mach's Principle . In: Physical Review Letter . 7, No. 9, 1961, pp. 359-360. doi : 10.1103 / PhysRevLett.7.359 .
  5. ↑ Dicke, RH: The Theoretical Significance of Experimental Relativity . Gordon and Breach, 1964.
  6. ^ Prestage, JD; Bollinger, JJ; Itano, WM; Wineland, DJ: Limits for spatial anisotropy by use of nuclear-spin-polarized Be-9 (+) ions . In: Physical Review Letters . 54, 1985, pp. 2387-2390. bibcode : 1985PhRvL..54.2387P . doi : 10.1103 / PhysRevLett.54.2387 .
  7. ↑ Phillips, PR: Test of spatial isotropy using a cryogenic spin-torsion pendulum . In: Physical Review Letter . 59, No. 5, 1987, pp. 1784-1787. bibcode : 1987PhRvL..59.1784P . doi : 10.1103 / PhysRevLett.59.1784 .
  8. ↑ Lamoreaux, SK; Jacobs, JP; Heckel, BR; Raab, FJ; Fortson, EN: Optical pumping technique for measuring small nuclear quadrupole shifts in 1S (0) atoms and testing spatial isotropy . In: Physical Review A . 39, 1989, pp. 1082-1111. bibcode : 1989PhRvA..39.1082L . doi : 10.1103 / PhysRevA.39.1082 .
  9. ↑ Chupp, TE; Hoare, RJ; Loveman, RA; Oteiza, ER; Richardson, JM; Wagshul, ME; Thompson, AK: Results of a new test of local Lorentz invariance: A search for mass anisotropy in 21Ne . In: Physical Review Letters . 63, No. 15, 1989, pp. 1541-1545. bibcode : 1989PhRvL..63.1541C . doi : 10.1103 / PhysRevLett.63.1541 .
  10. ↑ Wineland, DJ; Bollinger, JJ; Heinzen, DJ; Itano, WM; Raizen, MG: Search for anomalous spin-dependent forces using stored-ion spectroscopy . In: Physical Review Letters . 67, No. 13, 1991, pp. 1735-1738. bibcode : 1991PhRvL..67.1735W . doi : 10.1103 / PhysRevLett.67.1735 .
  11. ↑ Wang, Shih-Liang; Ni, Wei-Tou; Pan, Sheau-Shi: New Experimental Limit on the Spatial Anisotropy for Polarized Electrons . In: Modern Physics Letters A . 8, No. 39, 1993, pp. 3715-3725. bibcode : 1993MPLA .... 8.3715W . doi : 10.1142 / S0217732393003445 .
  12. ↑ Berglund, CJ; Hunter, LR; Krause, D., Jr .; Prigge, EO; Ronfeldt, MS; Lamoreaux, SK: New Limits on Local Lorentz Invariance from Hg and Cs Magnetometers . In: Physical Review Letters . 75, No. 10, 1995, pp. 1879-1882. bibcode : 1995PhRvL..75.1879B . doi : 10.1103 / PhysRevLett.75.1879 .
  13. ↑ Bear, D .; Stoner, RE; Walsworth, RL; Kostelecký, V. Alan; Lane, Charles D .: Limit on Lorentz and CPT Violation of the Neutron Using a Two-Species Noble-Gas Maser . In: Physical Review Letters . 85, No. 24, 2000, pp. 5038-5041. arxiv : physics / 0007049 . bibcode : 2000PhRvL..85.5038B . doi : 10.1103 / PhysRevLett.85.5038 .
  14. ↑ Phillips, DF; Humphrey, MA; Mattison, EM; Stoner, RE; Vessot, RF; Walsworth, RL: Limit on Lorentz and CPT violation of the proton using a hydrogen maser . In: Physical Review D . 63, No. 11, 2000, p. 111101. arxiv : physics / 0008230 . bibcode : 2001PhRvD..63k1101P . doi : 10.1103 / PhysRevD.63.111101 .
  15. ↑ Humphrey, MA; Phillips, DF; Mattison, EM; Vessot, RF; Stoner, RE; Walsworth, RL: Testing CPT and Lorentz symmetry with hydrogen masers . In: Physical Review A . 68, No. 6, 2003, p. 063807. arxiv : physics / 0103068 . bibcode : 2003PhRvA..68f3807H . doi : 10.1103 / PhysRevA.68.063807 .
  16. ↑ Hou, Li-Shing; Ni, Wei-Tou; Li, Yu-Chu M .: Test of Cosmic Spatial Isotropy for Polarized Electrons Using a Rotatable Torsion Balance . In: Physical Review Letters . 90, No. 20, 2003, p. 201101. arxiv : physics / 0009012 . bibcode : 2003PhRvL..90t1101H . doi : 10.1103 / PhysRevLett.90.201101 .
  17. ↑ Canè, F .; Bear, D .; Phillips, DF; Rosen, MS; Smallwood, CL; Stoner, RE; Walsworth, RL; Kostelecký, V. Alan: Bound on Lorentz and CPT Violating Boost Effects for the Neutron . In: Physical Review Letters . 93, No. 23, 2004, p. 230801. arxiv : physics / 0309070 . bibcode : 2004PhRvL..93w0801C . doi : 10.1103 / PhysRevLett.93.230801 .
  18. ↑ Wolf, P .; Chapelet, F .; Bize, S .; Clairon, A .: Cold Atom Clock Test of Lorentz Invariance in the Matter Sector . In: Physical Review Letters . 96, No. 6, 2006, p. 060801. arxiv : hep-ph / 0601024 . bibcode : 2006PhRvL..96f0801W . doi : 10.1103 / PhysRevLett.96.060801 .
  19. ↑ Heckel, BR; Cramer, CE; Cook, TS; Adelberger, EG; Schlamminger, S .; Schmidt, U .: New CP-Violation and Preferred-Frame Tests with Polarized Electrons . In: Physical Review Letters . 97, No. 2, 2006, p. 021603. arxiv : hep-ph / 0606218 . bibcode : 2006PhRvL..97b1603H . doi : 10.1103 / PhysRevLett.97.021603 .
  20. ↑ Heckel, BR; Adelberger, EG; Cramer, CE; Cook, TS; Schlamminger, S .; Schmidt, U .: Preferred-frame and CP-violation tests with polarized electrons . In: Physical Review D . 78, No. 9, 2008, p. 092006. arxiv : 0808.2673 . bibcode : 2008PhRvD..78i2006H . doi : 10.1103 / PhysRevD.78.092006 .
  21. ↑ Altarev, I. et al. : Test of Lorentz Invariance with Spin Precession of Ultracold Neutrons . In: Physical Review Letters . 103, No. 8, 2009, p. 081602. arxiv : 0905.3221 . bibcode : 2009PhRvL.103h1602A . doi : 10.1103 / PhysRevLett.103.081602 .
  22. ↑ Brown, JM; Smullin, SJ; Kornack, TW; Romalis, MV: New Limit on Lorentz- and CPT-Violating Neutron Spin Interactions . In: Physical Review Letters . 105, No. 15, 2010, p. 151604. arxiv : 1006.5425 . bibcode : 2010PhRvL.105o1604B . doi : 10.1103 / PhysRevLett.105.151604 .
  23. ↑ Gemmel, C .; Heil, W .; Karpuk, S .; Lenz, K .; Sobolev, Yu .; Tullney, K .; Burghoff, M .; Kilian, W .; Knappe-Grüneberg, S .; Müller, W .; Schnabel, A .; Seifert, F .; Trahms, L .; Schmidt, U .: Limit on Lorentz and CPT violation of the bound neutron using a free precession He3 / Xe129 comagnetometer . In: Physical Review D . 82, No. 11, 2010, p. 111901. arxiv : 1011.2143 . bibcode : 2010PhRvD..82k1901G . doi : 10.1103 / PhysRevD.82.111901 .
  24. ↑ M. Smiciklas et al. : New Test of Local Lorentz Invariance Using a 21Ne-Rb-K Comagnetometer . In: Physical Review Letters . 107, No. 17, 2011, p. 171604. arxiv : 1106.0738 . bibcode : 2011PhRvL.107q1604S . doi : 10.1103 / PhysRevLett.107.171604 .
  25. ↑ Peck et al. : New Limits on Local Lorentz Invariance in Mercury and Cesium . In: Physical Review A . 86, No. 1, 2012, p. 012109. arxiv : 1205.5022 . doi : 10.1103 / PhysRevA.86.012109 .
  26. ↑ Hohensee et al. : Limits on violations of Lorentz symmetry and the Einstein equivalence principle using radio-frequency spectroscopy of atomic dysprosium . In: Physical Review Letters . 111, No. 5, 2013, p. 050401. arxiv : 1303.2747 . doi : 10.1103 / PhysRevLett.111.050401 .
  27. ↑ Allmendinger et al. : New limit on Lorentz and CPT violating neutron spin interactions using a free precession 3He-129Xe co-magnetometer . In: Physical Review Letters . 112, No. 11, 2013, p. 110801. arxiv : 1312.3225 . doi : 10.1103 / PhysRevLett.112.110801 .

Web links