Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAn odd (parity) test of Lorentz symmetry with atomic dysprosium
131
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We propose using a Stark interference technique to directly measure the odd-parity c_{0j} components of the electron sector c_{mu u} tensor of the Standard-Model Extension. This technique has been shown to be a sensitive probe of parity violation in atomic dysprosium in a low-energy, tabletop experiment, and may also be straightforwardly applied to test Lorentz invariance. We estimate that such an experiment may be sensitive to c_{0j} coefficients as small as 10^{-18}.
rate research
Read More
All evidence so far suggests that the absolute spatial orientation of an experiment never affects its outcome. This is reflected in the Standard Model of physics by requiring all particles and fields to be invariant under Lorentz transformations. The most well-known test of this important cornerstone of physics are Michelson-Morley-type experimentscite{MM, Herrmann2009,Eisele2009} verifying the isotropy of the speed of light. Lorentz symmetry also implies that the kinetic energy of an electron should be independent of the direction of its velocity, textit{i.e.,} its dispersion relation should be isotropic in space. In this work, we search for violation of Lorentz symmetry for electrons by performing an electronic analogue of a Michelson-Morley experiment. We split an electron-wavepacket bound inside a calcium ion into two parts with different orientations and recombine them after a time evolution of 95ms. As the Earth rotates, the absolute spatial orientation of the wavepackets changes and anisotropies in the electron dispersion would modify the phase of the interference signal. To remove noise, we prepare a pair of ions in a decoherence-free subspace, thereby rejecting magnetic field fluctuations common to both ionscite{Roos2006}. After a 23 hour measurement, we limit the energy variations to $htimes 11$ mHz ($h$ is Plancks constant), verifying that Lorentz symmetry is preserved at the level of $1times10^{-18}$. We improve on the Lorentz-violation limits for the electron by two orders of magnitudecite{Hohensee2013c}. We can also interpret our result as testing the rotational invariance of the Coloumb potential, improving limits on rotational anisotropies in the speed of light by a factor of fivecite{Herrmann2009,Eisele2009}. Our experiment demonstrates the potential of quantum information techniques in the search for physics beyond the Standard Model.
We report a joint test of local Lorentz invariance and the Einstein equivalence principle for electrons, using long-term measurements of the transition frequency between two nearly degenerate states of atomic dysprosium. We present many-body calculations which demonstrate that the energy splitting of these states is particularly sensitive to violations of both special and general relativity. We limit Lorentz violation for electrons at the level of $10^{-17}$, matching or improving the best laboratory and astrophysical limits by up to a factor of 10, and improve bounds on gravitational redshift anomalies for electrons by 2 orders of magnitude, to $10^{-8}$. With some enhancements, our experiment may be sensitive to Lorentz violation at the level of $9times 10^{-20}$.
This article reports on the Fourth Meeting on Lorentz and CPT Symmetry, CPT 07, held in August 2007 in Bloomington, Indiana, USA. The focus is on recent tests of Lorentz symmetry using atomic and optical physics. Results presented at the meeting include improved bounds on Lorentz violation in the photon sector, and the first bounds on several coefficients in the gravity sector.
We calculate interaction constants for the contributions from PT-odd scalar-pseudoscalar and tensor-pseudotensor operators to the electric dipole moment of ${}^{129}$Xe, for the first time in case of the former, using relativistic many-body theory including the effects of dynamical electron correlations. These interaction constants are necessary ingredients to relating the corresponding measurements to fundamental parameters in models of physics beyond the Standard Model. We obtain $alpha_{C_S} = left( 0.71 pm 0.18 right) [10^{-23}, e~text{cm}]$ and $alpha_{C_T}= left( 0.520 pm 0.049 right) [10^{-20}, left<Sigmaright>_{text{Xe}}, e~text{cm}]$, respectively. We apply our results to test a phenomenological relation between the two quantities, commonly used in the literature, and discuss their present and future phenomenological impact.
Our improved calculation of the nuclear spin-independent parity violating electric dipole transition amplitude ($E1_{PV}$) for $6s ~ ^2S_{1/2} - 7s ~ ^2S_{1/2}$ in $^{133}$Cs in combination with the most accurate (0.3%) measurement of this quantity yields a new value for the nuclear weak charge $Q_W=-73.71(26)_{ex} (23)_{th}$ against the Standard Model (SM) prediction $Q_W^{text{SM}}=-73.23(1)$. The advances in our calculation of $E1_{PV}$ have been achieved by using a variant of the perturbed relativistic coupled-cluster theory which treats the contributions of the core, valence and excited states to $E1_{PV}$ on the same footing unlike the previous high precision calculations. Furthermore, this approach resolves the controversy regarding the sign of the core correlation effects. We discuss the implications of the deviation of our result for $Q_W$ from the SM value by considering different scenarios of new physics.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
