Limits on Light-Speed Anisotropies from Compton Scattering of High-Energy Electrons

Abstract

The possibility of anisotropies in the speed of light relative to the limiting speed of electrons is considered. The absence of sidereal variations in the energy of Compton-edge photons at the European Synchrotron Radiation Facility's GRAAL facility constrains such anisotropies representing the first nonthreshold collision-kinematics study of Lorentz violation. When interpreted within the minimal standard-model extension, this result yields the two-sided limit of 1.6×10(-14) at 95% confidence level on a combination of the parity-violating photon and electron coefficients (κ(o+))(YZ), (κ(o+))(ZX), c(TX), and c(TY). This new constraint provides an improvement over previous bounds by 1 order of magnitude.

Renormalization of scalar and Yukawa field theories with Lorentz violation

“…This is consistent with Eqs. (26), (32), and (33) by noting that the function Å becomes Å ! ð1 þ CÞ À2 .…”

“…Examinations of fermion-photon interactions have led to bounds on many of the parameters contained in the SME [20][21][22][23][24][25][26][27]. The Yukawa sector has been rather little studied in the SME context [28][29][30], in spite of its great importance for mass generation in the SM.…”

Improved constraints on isotropic shift and anisotropies of the speed of light using rotating cryogenic sapphire oscillators

“…This could happen if known particles interact with fields not accounted for by the standard model, or indeed if Lorentz symmetry turns out to be explicitly broken. In this context, modern implementations of Michelson-Morley, Kennedy-Thorndike, and Ives-Stilwell tests [4][5][6][7][8][9] are used to look for evidence of such Lorentz violation in the form of modifications of the dispersion relation for light and other standard model particles. In particular, these tests search for deviations of the phase velocity of light in vacuum from the canonical value.…”

Triangular Ring Resonator: Direct Measurement of the Parity-Odd Parameters of the Photon Sector of Sme

“…The local constraints can be provided by accelerators. For example not having observed the Compton-edge photons at the ESRF's GRAAL facility [24,25] leads to the bound of 10 −13 on the mSME coefficients. There exist proposals to measure the parity-odd LIV terms at the level of 10 −16 by the electrostatics or magnetostatics systems [4][5][6].…”

“…This model adds all the perturbative parameters breaking the Lorentz symmetry to the Lagrangian of the standard model before asking how much which experiment or observation constrains them. This model has stemmed recent research aimed to detect or study the Lorentz Invariance Violation (LIV) terms for electromagnetic (photon sector of the SME) in various fields, including the classical solutions of SME electrodynamics [4][5][6][7], cosmological birefringence constraints [8][9][10], radiation spectrum of the electromagnetic waves and CMB data [11][12][13][14][15][16][17], black body radiation in finite temperature [18][19][20][21], LIV terms in higher dimensional scenarios [22,23], synchrotron radiation [24,25], Cherenkov radiation [26][27][28][29] and modern cavity resonators or interferometry experiments [30][31][32][33][34][35]. Studies have been conducted to search for the LIV terms in the neutrino sector [36][37][38][39][40][41][42], meson sector [43][44][45][46]…”