Quantum Systems in Weak Gravitational Fields

Papini, G.

doi:10.1007/978-94-010-0347-6_13

Cited by 8 publications

(7 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The effect extends our knowledge of rotational inertia to the quantum level and violates the principle of equivalence [5] while preserving invariance under P and T . It has physical and astrophysical implications [3,6,7,8] and also plays a fundamental role in precise measurements of the g − 2 factor of the muon [8].Recently, a discrepancy a µ (exp) − a µ (SM ) = 43 × 10 −10 has been observed [9] between the experimental and standard model values of the muon's anomalous g value, a µ = g−2 2 . This discrepancy can be used to set an upper limit on P and T invariance violations in spinrotation coupling.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Of all the terms that appear in the Dirac Hamiltonian, only the Mashhoon term couples the helicity states of the muon. The remaining terms contribute to the overall energy E of the states and the corresponding part of the Hamiltonian is indicated by H 0 [8].…”

mentioning

confidence: 99%

“…Hence the necessity of accounting for spinrotation coupling whose contribution cancels the factor eB m in (15) [8]. Substituting κ 1 = 1 + ǫ 1 , κ 2 = 1 + ǫ 2 into (13), one finds…”

mentioning

confidence: 99%

See 3 more Smart Citations

Parity and time reversal in the spin-rotation interaction

Papini

2002

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

A recently reported discrepancy between experimental and theoretical values of the muon's g − 2 factor is interpreted as due to small violations of the conservation of P and T in the spin-rotation coupling. The experiments place an upper limit on these violations and on the weight change of spinning gyroscopes.PACS numbers: 11.30. Er, 04.20.Cv, 04.90.+e, The spin-rotation effect described by Mashhoon [1] attributes an energy −h 2 ω · σ to a spin-1 2 particle in a frame rotating with angular velocity ω relative to an inertial frame. Identical results have been derived directly from the Dirac equation by means of the tetrad formalism [2,3,4]. The effect extends our knowledge of rotational inertia to the quantum level and violates the principle of equivalence [5] while preserving invariance under P and T . It has physical and astrophysical implications [3,6,7,8] and also plays a fundamental role in precise measurements of the g − 2 factor of the muon [8].Recently, a discrepancy a µ (exp) − a µ (SM ) = 43 × 10 −10 has been observed [9] between the experimental and standard model values of the muon's anomalous g value, a µ = g−2 2 . This discrepancy can be used to set an upper limit on P and T invariance violations in spinrotation coupling.The possibility that discrete symmetries in gravitation be not conserved has been considered by some authors [10,11,12,13]. Attention has in general focused on the potential (in unitsh = c = 1)which applies to a particle of generic spin σ. The first term, introduced by Leitner and Okubo [11], violates the conservation of P and T . The same authors determined the upper limit α 1 ≤ 10 −11 from the hyperfine splitting of the ground state of hydrogen. The upper limit α 2 ≤ 10 −3 was determined in Ref.[13] from SN 1987A data. The corresponding potential violates the conservation of P and C. Conservation of C and T is violated by the last term, while (1), as a whole, conserves CP T . There is, as yet, no upper limit on α 3 . These studies are extended here to the Mashhoon term.The g − 2 experiment involves muons in a storage ring [14]. As the muons decay, the angular distribution of those electrons projected forward in the direction of motion reflect the precession of the muon spin along the cyclotron orbits.Assume that all quantities in the effective Hamiltonian are time-independent and referred to a left-handed tern of axes comoving with the muons and rotating about the x 2 -axis in the clockwise direction of motion of the muons. The x 3 -axis is tangent to the orbits and in the direction of the muon momentum. The magnetic field is B 2 = −B. Of all the terms that appear in the Dirac Hamiltonian, only the Mashhoon term couples the helicity states of the muon. The remaining terms contribute to the overall energy E of the states and the corresponding part of the Hamiltonian is indicated byBefore decay, the muon states can be represented bywhere | ψ + > and | ψ − > are the right and left helicity states of the Hamiltonian H 0 and satisfy the equationAssume now that the coupling of rotation...

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

“…Hence the necessity of accounting for spinrotation coupling whose contribution cancels the factor eB m in (15) [8]. Substituting κ 1 = 1 + ǫ 1 , κ 2 = 1 + ǫ 2 into (13), one finds…”

mentioning

confidence: 99%

See 2 more Smart Citations

Parity and time reversal in the spin-rotation interaction

Papini

2002

Phys. Rev. D

Self Cite

View full text Add to dashboard Cite

show abstract

“…This should be expected, because in metric theories of gravitation [30], general relativity in particular, the space parameter of Berry's theory coincides with space-time. It has been shown that the wave equations for fermions and bosons can be solved exactly to first order in the metric deviation γ µν = g µν − η µν for any metric g µν and that the phases so calculated [20,[31][32][33][34] give reliable results in interferometry, gyroscopy [28] and optics [35,36], give the correct Einstein deflection, can be used in the study of neutrino helicity and flavour oscillations [37] and of spin-gravity coupling in general [31,34]. They also reproduce a variety of known effects, as discussed in [32,33,38].…”

Section: Introductionmentioning

confidence: 99%

Perspectives on Gravity-Induced Radiative Processes in Astrophysics

Papini

2015

Galaxies

View full text Add to dashboard Cite

Single-vertex Feynman diagrams represent the dominant contribution to physical processes, but are frequently forbidden kinematically. This is changed when the particles involved propagate in a gravitational background and acquire an effective mass. Procedures are introduced that allow the calculation of lowest order diagrams, their corresponding transition probabilities, emission powers and spectra to all orders in the metric deviation, for particles of any spin propagating in gravitational fields described by any metric. Physical properties of the "space-time medium" are also discussed. It is shown in particular that a small dissipation term in the particle wave equations can trigger a strong back-reaction that introduces resonances in the radiative process and affects the resulting gravitational background.

show abstract