Browsing by Author "Lane, C.D."

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Clock-comparison tests of Lorentz and CPT symmetry in space
(American Physical Society, 2002) Bluhm, R.; Kostelecký, V.A.; Lane, C.D.; Russell, N.
Clock-comparision experiments on satellite and other spacecarft were used to determine unmeasured coefficients for Lorentz and CPT violation. The presence of Lorentz and CPT violation caused frequency shifts in certain Zeeman hyperfine transitions. A broad range of tests with Planck-scale sensitivity were permitted by the orbital configuration of a satellite platform and the relatively large velocities attainable in a deep-space mission.
Constraints on Lorentz violation from clock-comparison experiments
(American Physical Society, 1999) Kostelecký, V.A.; Lane, C.D.
Constraints from clock-comparison experiments on violations of Lorentz and CPT symmetry are investigated in the context of a general Lorentz-violating extension of the standard model. The experimental signals are shown to depend on the atomic and ionic species used as clocks. Certain experiments usually regarded as establishing comparable bounds are in this context sensitive to different types of Lorentz violation. Some considerations relevant to possible future measurements are presented. All these experiments are potentially sensitive to Lorentz-violating physics at the Planck scale.
$CPT$ and Lorentz tests with muons
(American Physical Society, 2000) Bluhm, R.; Kostelecký, V.A.; Lane, C.D.
Precision experiments with muons are sensitive to Planck-scale $CPT$ and Lorentz violation that is undetectable in other tests. Existing data on the muonium ground-state hyperfine structure and on the muon anomalous magnetic moment could be analyzed to provide dimensionless figures of merit for $CPT$ and Lorentz violation at the levels of $4 × 10^{-21}$ and $10^{-23}$.
Limit on Lorentz and $CPT$ Violation of the Neutron Using a Two-Species Noble-Gas Maser
(American Physical Society, 2000) Bear, D.; Stoner, R.E.; Walsworth, R.L.; Kostelecký, V.A.; Lane, C.D.
A search for sidereal variations in the frequency difference between co-located $^{129}\text{Xe}$ and $^{3}\text{He}$ Zeeman masers sets the most stringent limit to date on leading-order Lorentz and $CPT$ violation involving the neutron, consistent with no effect at the level of $10^{−31}$ $\text{GeV}$.
Noncommutative field theory and Lorentz violation
(American Physical Society, 2001) Carroll, S.M.; Harvey, J.A.; Kostelecký, V.A.; Lane, C.D.; Okamoto, T.
The role of Lorentz symmetry in noncommutative field theory is considered. Any realistic noncommutative theory is found to be physically equivalent to a subset of a general Lorentz-violating standard-model extension involving ordinary fields. Some theoretical consequences are discussed. Existing experiments bound the scale of the noncommutativity parameter to $(10$ $\text{TeV})^{-2}$.
Nonrelativistic quantum Hamiltonian for Lorentz violation
(AIP Publishing, 1999) Kostelecký, V.A.; Lane, C.D.
A method is presented for deriving the nonrelativistic quantum Hamiltonian of a free massive fermion from the relativistic Lagrangian of the Lorentz-violating standard-model extension. It permits the extraction of terms at arbitrary order in a Foldy–Wouthuysen expansion in inverse powers of the mass. The quantum particle Hamiltonian is obtained and its nonrelativistic limit is given explicitly to third order.
One-loop renormalization of Lorentz-violating electrodynamics
(American Physical Society, 2002) Kostelecký, V.A.; Lane, C.D.; Pickering, A.G.M.
We show that the general Lorentz- and CPT-violating extension of quantum electrodynamics is one-loop renormalizable. The one-loop Lorentz-violating beta functions are obtained, and the running of the coefficients for Lorentz and CPT violation is determined. Some implications for theory and experiment are discussed.
Probing Lorentz and $CPT$ violation with space-based experiments
(American Physical Society, 2003) Bluhm, R.; Kostelecký, V.A.; Lane, C.D.; Russell, N.
Space-based experiments offer sensitivity to numerous unmeasured effects involving Lorentz and $CPT$ violation. We provide a classification of clock sensitivities and present explicit expressions for time variations arising in such experiments from nonzero coefficients in the Lorentz- and $CPT$-violating Standard-Model Extension.