Applications of the general theory of quantum electrodynamics with Lorentz- and CPT-violating operators of mass dimensions up to six are presented to Penning-trap experiments comparing charge-to-mass ratios between particles and antiparticles. Perturbation theory is used to derive Lorentz- and CPT-violating contributions to the energy levels and cyclotron frequencies of confined particles and antiparticles. We show that whether the experimental {\it interpreted} quantity $(|q|/m)_{\overline{w}}/(|q|/m)_{w} - 1$ is a clean measure of a CPT test depends on the context of the relevant theory. Existing experimental results of charge-to-mass ratio comparisons are used to obtain first-time constraints on 69 coefficients for Lorentz and CPT violation.
This talk discusses the sensitivity of electron-positron and proton-antiproton Penning-trap experiments to CPT- and Lorentz-violating effects in the context of an extension of the minimal standard model and quantum electrodynamics.
The theoretical and experimental prospects for Lorentz- and CPT-violating quantum electrodynamics in Penning traps are reviewed in this work. With the recent reported results for the measurements of magnetic moments for both protons and antiprotons, improvements with factors of up to 3000 for the constraints of various coefficients for Lorentz and CPT violation are obtained.
A modified Dirac equation with general Lorentz- and CPT-violating operators in the electromagnetic field is studied. Constraints on and possible sensitivities to Lorentz-violating coefficients in the nonminimal sector up to mass-dimension six can be obtained by analyzing Penning-trap results involving anomaly frequencies.
An overview of recent progress on testing Lorentz and CPT symmetry using Penning traps is presented. The theory of quantum electrodynamics with Lorentz-violating operators of mass dimensions up to six is summarized. Dominant shifts in the cyclotron and anomaly frequencies of the confined particles and antiparticles due to Lorentz and CPT violation are derived. Existing results of the comparisons of charge-to-mass ratios and magnetic moments involving protons, antiprotons, electrons, and positrons are used to constrain various coefficients for Lorentz violation.
The theoretical prospects for quantum electrodynamics with Lorentz-violating operators of mass dimensions up to six are revisited in this work. The dominant effects due to Lorentz and CPT violation are studied in measurements of magnetic moments of particles confined in Penning traps. Using recently reported experimental results, new coefficients for Lorentz violation are constrained and existing bounds of various coefficients are improved.
The CPT theorem has been tested to very high precision in a variety of experiments involving particles and antiparticles confined within Penning traps. These tests include comparisons of anomalous magnetic moments and charge-to-mass ratios of electrons and positrons, protons and antiprotons, and hydrogen ions and antiprotons. We present a theoretical analysis of possible signals for CPT and Lorentz violation in these systems. We use the framework of Colladay and Kostelecký, which consists of a general extension of the $SU(3) \times SU(2) \times U(1)$ standard model including possible CPT and L…
We present a theoretical analysis of signals for CPT and Lorentz violation in g-2 and charge-to-mass-ratio experiments on electrons and positrons in Penning traps. Experiments measuring anomaly frequencies are found to be the most sensitive to CPT violation. We find that the conventional figure of merit for CPT breaking, involving the difference of the electron and positron g factors, is inappropriate in this context, and an alternative is introduced. Bounds of approximately one part in 10^{20} are attainable.
A theoretical analysis is performed of Penning-trap experiments comparing protons and antiprotons to test CPT and Lorentz symmetry through measurements of anomalous magnetic moments and charge-to-mass ratios. Possible CPT and Lorentz violations arising at a fundamental level are treated in the context of a general extension of the standard model of particle physics and its restriction to quantum electrodynamics. In a suggested experiment measuring anomaly frequencies a bound on CPT violation of 10^{-23} for a relevant figure of merit is attainable. Experiments comparing cyclotron frequencies a…
A theoretical analysis is performed of Penning-trap experiments testing CPT and Lorentz symmetry through measurements of anomalous magnetic moments and charge-to-mass ratios. Possible CPT and Lorentz violations arising from spontaneous symmetry breaking at a fundamental level are treated in the context of a general extension of the SU(3) x SU(2) x U(1) standard model and its restriction to quantum electrodynamics. We describe signals that might appear in principle, introduce suitable figures of merit, and estimate CPT and Lorentz bounds attainable in present and future Penning-trap experiments…
The prospects are explored for testing Lorentz- and CPT-violating quantum electrodynamics in experiments with Penning traps. We present the Lagrange density of Lorentz-violating spinor electrodynamics with operators of mass dimensions up to six, and we discuss some of its properties. The theory is used to derive Lorentz- and CPT-violating perturbative shifts of the energy levels of a particle confined to a Penning trap. Observable signals are discussed for trapped electrons, positrons, protons, and antiprotons. Existing experimental measurements on anomaly frequencies are used to extract new o…
An overview of recent progress on searches for Lorentz- and CPT-violating signals with confined particles and antiparticles in Penning traps is presented. In the context of the Standard-Model Extension (SME), leading-order shifts in the cyclotron and anomaly frequencies of a confined particle and antiparticle due to Lorentz and CPT violation are provided. The two frequencies are then related to comparisons of charge-to-mass ratios and magnetic moments between particles and antiparticles. Applying reported results from Penning-trap experiments leads to new limits on various coefficients for Lor…
A general theoretical framework that incorporates possible CPT and Lorentz violation in an extension of the standard model and in quantum electrodynamics has been developed over the last decade. The framework originates in the idea that CPT and Lorentz symmetry could be broken spontaneously in a more fundamental theory such as string theory. These symmetry violations are described in the standard-model extension by small terms in the Lagrangian. Various experiments can bound these quantities. They include Penning-trap experiments with electrons and positrons, Penning-trap experiments with prot…
Possibilities for testing Lorentz symmetry using precision experiments with antiprotons in Penning traps and with antihydrogen spectroscopy are reviewed. Estimates of bounds on relevant coefficients for Lorentz violation in the Standard-Model Extension (SME) are considered.
A review of recent theoretical work investigating tests of Lorentz and CPT symmetry in atomic and particle systems is presented. A variety of tests in matter and antimatter are discussed, including measurements of anomalous magnetic moments in Penning traps, comparisons of atomic-clock transitions, high-precision spectroscopic measurements of hydrogen and antihydrogen, experiments with muons, experiments with mesons, and tests of Lorentz symmetry with a spin-polarized torsion pendulum.
Lorentz and CPT tests involving matter-antimatter comparisons at low temperatures are discussed. SME predictions for transition frequencies in such systems include both matter-antimatter differences and sidereal variations. In hydrogen-antihydrogen spectroscopy, leading-order effects in a 1S-2S transition as well as in a 1S Zeeman transition could exist that can be employed to obtain clean constraints. Similarly, tight bounds can be determined from Penning-trap experiments involving antiprotons.
An overview of the theoretical framework of the Standard Model Extension (SME) that allows for a parametrization of Lorentz and CPT violating effects using effective field theory will be presented. A review of current bounds on these Lorentz violating parameters using various low-energy tests will be reviewed. State-of-the-art measurements involving the Penning Trap, atomic clock, torsion pendulum, and resonant cavities will be discussed. Different experiments can provide stringent bounds on a variety of parameters coupled to various fundamental particles including electrons, protons, neutrons…
The possibility of testing spatial noncommutativity via a Penning trap is explored. The case of both space-space and momentum-momentum noncommuting is considered. Spatial noncommutativity leads to the spectrum of the orbital angular momentum of a Penning trap possessing fractional values, and in the limits of vanishing kinetic energy and subsequent vanishing magnetic field, this system has non-trivial dynamics. The dominant value of the lowest orbital angular momentum is $\hbar/4$, which is a clear signal of spatial noncommutativity. An experimental verification of this prediction by a Stern-G…
The hamiltonian describing a single fermion in a Penning trap is shown to be supersymmetric in certain cases. The supersymmetries of interest occur when the ratio of the cyclotron frequency to the axial frequency is 3/2 and the particle has anomalous magnetic moment 4/3 or 2/3. At these supersymmetric points, the spectrum shows uniformly spaced crossed levels. The associated superalgebras are su(2|1) and su(1|1). The phase space for this problem has an osp(2|6) structure and contains all the degeneracy superalgebras.
The formulation and some experimental implications of a general Lorentz-violating extension of the standard model are reviewed. The theory incorporates both CPT-preserving and CPT-breaking terms. It is otherwise a conventional quantum field theory, obtained under the assumption that Lorentz symmetry is spontaneously broken in an underlying model. The theory contains the usual standard-model gauge structure, and it is power-counting renormalizable. Energy and momentum are conserved. Despite the violation of Lorentz symmetry, the theory exhibits covariance under Lorentz transformations of the ob…
Atomic physics can probe the Lorentz and CPT symmetries at the Planck level. Bounds on coefficients for Lorentz violation have been found using atomic clocks, masers, electromagnetic cavities, and Penning traps, among others, and in future it may be possible to place bounds using spectroscopy of antihydrogen atoms. The CPT '04 Meeting on CPT and Lorentz Symmetry was held in August 2004 in Bloomington, Indiana, USA, and covered Lorentz violation in all branches of physics. This report gives an overview of the recent advances in Lorentz-symmetry studies in atomic and optical physics.
By analyzing the analogies between the effective system of $N$ spins described by the Ising Hamiltonian and the phenomenon of the self--gravity in mixed particle systems, we show that cooled ions held in a segmented ion trap and exposed to a magnetic field gradient can simulate the proposed mechanism of mutual interaction in mixed neutrino system. We show that with trapped ions one can reproduce the expected corrections to the flavor transitions and the $CPT$ violation induced by gravity on flavor fields, which may have played an important role in the early stages of the universe. The results …
We constrain the coupling between axionlike particles (ALPs) and photons, measured with the superconducting resonant detection circuit of a cryogenic Penning trap. By searching the noise spectrum of our fixed-frequency resonant circuit for peaks caused by dark matter ALPs converting into photons in the strong magnetic field of the Penning-trap magnet, we are able to constrain the coupling of ALPs with masses around $2.7906-2.7914\,\textrm{neV/c}^2$ to $g_{aγ}< 1 \times 10^{-11}\,\textrm{GeV}^{-1}$. This is more than one order of magnitude lower than the best laboratory haloscope and approximat…
A recent Penning-trap measurement of the masses of 46V and 46Ti leads to a Qec value that disagrees significantly with the previously accepted value, and destroys overall consistency among the nine most precisely characterized T=1 superallowed beta emitters. This raises the possibility of a systematic discrepancy between Penning-trap measurements and the reaction-based measurements upon which the Qec values depended in the past. We carefully re-analyze (n,gamma) and (p,gamma) reaction measurements in the 24 \leq A \leq 28 mass region, and compare the results to very precise Penning-trap measur…
