相关论文: Elementary quantum mechanics of the neutron with a…
We point out that the electric dipole moment of the neutron in the Standard Model is generated already at tree level to the second order in the weak interactions due to bound-state effects, without short-distance Penguin loops. The related…
It has been shown recently that a neutron placed in an external quasistatic electric field develops an induced electric dipole moment $\mathbf{p}_{\mathrm{IND}}$ due to quantum fluctuations in the QED vacuum. A feasible experiment which…
When the magnetic moment of neutron m presesses around a static magnetic field B the electric dipole moment of neutron dn is tied up with m and rotates in the plane perpendicular to B with Larmor frequency wp. If to apply the oscillating…
For a bound state internal wave function respecting parity symmetry, it can be rigorously argued that the mean electric dipole moment must be strictly zero. Thus, both the neutron, viewed as a bound state of three quarks, and the water…
We present the result of an experiment to measure the electric dipole moment (EDM) of the neutron at the Paul Scherrer Institute using Ramsey's method of separated oscillating magnetic fields with ultracold neutrons (UCN). Our measurement…
Quantum fluctuations in the QED vacuum generate non-linear effects, such as peculiar induced electromagnetic fields. In particular, we show here that an electrically neutral particle, possessing a magnetic dipole moment, develops an induced…
A nonzero electric dipole moment (EDM) of the neutron, proton, deuteron or helion, in fact, of any finite system necessarily involves the breaking of a symmetry, either by the presence of external fields (i.e. electric fields leading to the…
We have measured the neutron electric dipole moment using spin rotation in a non-centrosymmetric crystal. Our result is d_n = (2.5 +- 6.5(stat) +- 5.5(syst)) 10^{-24} e cm. The dominating contribution to the systematic uncertainty is…
A permanent electric dipole moment (EDM) of a fundamental particle violates both parity (P) and time (T) reversal symmetry and combined charge and parity (CP) reversal symmetry if the combined reversal of charge, parity \textit{and} time…
The electric dipole moments (EDMs) of neutron-odd nuclei with even protons are systematically evaluated. We first derive the relation between the EDM and the magnetic moment operators by making use of the core polarization scheme. This…
An experiment using a prototype setup to search for the neutron electric dipole moment by measuring spin-rotation in a non-centrosymmetric crystal (quartz) was carried out to investigate statistical sensitivity and systematic effects of the…
We present a complete three-loop calculation of the electric dipole moment of the $u$ and $d$ quarks in the Standard Model. For the $d$ quark, more relevant for the experimentally important neutron electric dipole moment, we find…
Trapped ultracold neutrons (UCN) have for many years been the mainstay of experiments to search for the electric dipole moment (EDM) of the neutron, a critical parameter in constraining scenarios of new physics beyond the Standard Model.…
We calculate the electric dipole moment (EDM) for the neutron in the framework of the minimal 3-3-1 model. We assume that the only source of $CP$ violation arises from a complex trilinear coupling constant and two complex vacuum expectation…
We propose an original test of Lorentz invariance in the interaction between a particle spin and an electromagnetic field and report on a first measurement using ultracold neutrons. We used a high sensitivity neutron electric dipole moment…
Electric dipole moments are extremely sensitive probes of physics beyond the Standard Model. A vibrant experimental program is in place, with the goal of improving existing bounds on the electron and neutron electric dipole moments by one…
We compute the electric dipole moment d_n of the neutron from a fully dynamical simulation of lattice QCD with 2+1 flavors of clover fermions and nonvanishing theta term. The latter is rotated into the pseudoscalar density in the fermionic…
An experimental search for an electric-dipole moment (EDM) of the neutron has been carried out at the Institut Laue-Langevin (ILL), Grenoble. Spurious signals from magnetic-field fluctuations were reduced to insignificance by the use of a…
The electric dipole moments of various neutral elementary particles, such as neutron, neutrinos, certain hypothetical dark matter particles and others, are predicted to exist by the standard model of high energy physics and various…
A point-like neutron in an external electromagnetic field experiences a shift in energy that mimicks the effect of an actual structural deformation of an extended neutron, i.e., a proper polarizability. In order to be able to differentiate…