The electric dipole moment of the muon

The forthcoming experiment [1] on the anomalous magnetic moment of the muon will be able to search also for an electric dipole momentd _μ of the muon with increased sensitivity. A brief survey is given on what various models of CP violation predict ford _μ.     

Nuclear electric dipole moment of He

A permanent electric dipole moment (EDM) of a physical system requires time-reversal (T) and parity (P) violation. Experimental programs are currently pushing the limits on EDMs in atoms, nuclei, and the neutron to regimes of fundamental theoretical interest. Here we calculate the magnitude of the P-, T-violating EDM of ³He and the expected sensitivity of such a measurement to the underlying P-, T-violating interactions. Assuming that the coupling constants are of comparable magnitude for π-, ρ-, and ω-exchanges, we find that the pion-exchange contribution dominates. Our results suggest that a measurement of the ³He EDM is complementary to the planned neutron and deuteron experiments, and could provide a powerful constraint for the theoretical models of the pion–nucleon P-, T-violating interaction.     

New measurements of the neutron electric dipole moment

We report a new measurement of the neutron electric dipole moment with the PNPI EDM spectrometer using the ultracold neutron source PF2 at the research reactor of the ILL. Its first results can be interpreted as a limit on the neutron electric dipole moment of |d _n | < 5.5 × 10^?26 e cm (90% confidence level).     

The electric dipole moment of methyl fluoride

The Stark effect of CH₃F is extensively used as a calibration standard in laser Stark spectroscopy. The accepted value for the dipole moment of the ground vibrational state of CH₃F is less accurate than the precision of laser Stark measurements, and questions have also been raised about the literature value. New molecular beam spectroscopy measurements have been made of the ratio of the Stark effect in the J = 1, K = 1 and J = 2, K = 2 CH₃F states to that of the 01¹0 vibrational state of OCS. The results were $\text{μ}{}_{1.1}\text{(}\text{CH}{}_3\text{F}\text{)}\text{μ}{}_{010}\text{(}\text{OCS}\text{)}\text{= 2.638905(23)}$ and $\text{μ}{}_{2.2}\text{(}\text{CH}{}_3\text{F}\text{)}\text{μ}{}_{010}\text{(}\text{OCS}\text{)}\text{= 2.63894(10)}$. This produces a dipole moment of 1.85840 D with precision relative to OCS of 10 ppm and absolute accuracy of 43 ppm.     

New limit on the electron electric dipole moment

We present the result of our most recent search for T violation in 205Tl, which is interpreted in terms of an electric dipole moment of the electron d(e). We find d(e) = (6.9 +/- 7.4)x10(-28)e cm, which yields an upper limit /d(e)/ < or = 1.6x10(-27)e cm with 90% confidence. The present apparatus is a major upgrade of the atomic beam magnetic-resonance device used to set the previous limit on d(e).     

New insights into the neutron electric dipole moment

We analyze the CP-violating electric dipole form factor of the nucleon in the framework of covariant baryon chiral perturbation theory. We give a new upper bound on the vacuum angle, |θ₀|?2.5×¹⁰⁻¹⁰$|{\theta }_0|?2.5\times {10}^{-10}$. The quark mass dependence of the electric dipole moment is discussed and compared to lattice QCD data. We also perform the matching between its representations in the three- and two-flavor theories.     

Quantum holonomies for an electric dipole moment

In this Letter, we obtain the quantum holonomies for a neutral particle with a permanent electric dipole moment based on the analogue effects of the He-McKellar-Wilkens effect and the Scalar Aharonov-Bohm effect and show a new proposal for implementing one-qubit quantum gates.     

Critical electric dipole moment in one dimension

The magnitude of an electric dipole moment must be larger or equal to a certain value to support bound states. Such critical dipole moment, pcrit, has been calculated in 2 and 3 dimensions and has been suggested that its calculation in one dimension cannot be possible. We evaluate pcrit in one dimension showing that the previous suggestion is untenable.     

Static electric dipole polarizability of lithium atoms in Debye plasmas

<正>The static electric dipole polarizabilities of the ground state and n≤3 excited states of a lithium atom embedded in a weekly coupled plasma environment are investigated as a function of the plasma screening radium.The plasma screening of the Coulomb interaction is described by the Debye-H（u|¨）ckel potential and the interaction between the valence electron and the atomic core is described by a model potential.The electron energies and wave functions for both the bound and continuum states are calculated by solving the Schrodinger equation numerically using the symplectic integrator.The oscillator strengths,partial-wave,and total static dipole polarizabilities of the ground state and n≤3 excited states of the lithium atom are calculated.Comparison of present results with those of other authors, when available,is made.The results for the 2s ground state demonstrated that the oscillator strengths and the static dipole polarizabilities from np orbitals do not always increase or decrease with the plasma screening effect increasing, unlike that for hydrogen-like ions,especially for 2s→3p transition there is a zero value for both the oscillator strength and the static dipole polarizability for screening length D = 10.3106a₀,which is associated with the Cooper minima.     

运动介质的电偶极矩与磁矩

在推导出介质的极化强度与磁化强度的坐标变换公式的基础上,分析导出了运动介质的电偶极矩与磁矩.