Intrinsic Electric Dipole Research Articles

Die Bewegung des Polarisationsvektors eines Dirac-Teilchens im makroskopischen elektromagnetischen Feld

The equations of motion of the polarisation is derived for a relativistic Diracparticle that has an anomalous magnetic moment and an intrinsic electric dipole moment and moves in a macroscopic electromagnetic field. This is done by starting from the well known motion of the polarisation in the restsystem and using relativistic kinematics. The general results are discussed for some special fields.

Upper limit for the intrinsic electric dipole moment of the proton and the neutrino

The elastic scattering of electrons by a proton with an intrinsic electric dipole moment (e.d.m.) is calculated in first Born approximation. The cross section is quite sensitive to the e.d.m. interaction at high energies and large angles. It therefore seems likely that high energy electron-proton scattering may give valuable information of the value or upper limit of the proton e.d.m. coupling strength. Certain spin correlation effects between the recoil proton and the initial electron arising from the e.d.m. interaction are also discussed. In the last section the calculation of the ionization power of a neutrino due to its intrinsic e.d.m. is briefly outlined and compared with the experimental results of Cowan and Reines.

Double Scattering of Electrons with a Dipole Moment

The double scattering of electrons with a small intrinsic electric dipole moment is investigated theoretically for the case where magnetic and electric fields are present in the space between the two targets. It is shown by using density matrix techniques that the plane of polarization of the electron beam, after the first scattering, would be rotated by the magnetic and electric fields just as predicted by regarding the electrons as classical spinning tops with magnetic moments and classical electric dipoles precessing about the directions of the magnetic and electric fields, respectively.

Scattering of Electrons with an Intrinsic Electric Dipole Moment

The elastic scattering of electrons with a small intrinsic electric dipole moment (e.d.m.) by spinless targets is discussed in the first and second Born approximations. For large momentum transfer (q ~ 500 Mev/c) the e.d.m. contribution to the elastic scattering cross section becomes important even for values lambda ~10/sup -3/ (where lambda is the e.d.m. in units of e times the Compton wave length of the electron). Thus, it seems likely that experiments involving high-energy electrons may give valuable information on the hypothetical existence and upper limit of the e.d.m. interaction. it is found, in the first Born approximation, that at sufficientiy high energies the existence of the e.d.m. can change the polarization of the electron beam from longitudinal to transverse. Finally, asymmetry effects which appear in the second Born approximation are discussed in detail. Detection of these asymmetries or of the spin correlation effects of the first Born approxi-mation mentioned above would imply the noninvariance of the electromagnetic interactions under parity and time reversal. (auth)