Decays, contact P-wave interactions and hyperfine structure in exotic atoms

Abstract

Contact P -wave interactions connected to the Larmor interaction of a magnetic dipole and Thomas spin precession in the filed of an electric quadrupole are described and their implications for spectroscopy of exotic Ω − -atoms are studied. In order to evaluate the magnitude of the contact P -wave interactions as compared to the conventional long-range interactions and the sensitivity of spectroscopic data to the Ω − -hyperon quadrupole moment, we consider 2P states of Ω − atoms formed with light stable nuclei with spins I 1/2 and atomic numbers Z 10. The energy level splitting caused by the contact interactions is 2-5 orders of magnitude smaller than the conventional long-range interactions. Strong decay widths of pΩ − atoms due to reactions pΩ − → ΛΞ 0 and pΩ − → ΣΞ , induced by t-channel kaon exchanges, are calculated. Ω − atoms formed with the light nuclei have strong widths 5-6 orders of magnitude higher than splitting caused by the contact interactions. The low-L pattern in the energy spectra of intermediate-and high-Z Ω − atoms thus cannot be observed. The Ω − quadrupole moment can be measured by observing X-rays from circular transitions between high-L levels in Ω − exotic atoms. The effect of strong interactions in 208 PbΩ − atoms is negligible starting from L ∼ 10. The contact P -wave interactions exist in ordinary atoms and μ-meson atoms.

Rotation of the swing plane of Foucault's pendulum and Thomas spin precession: two sides of one coin

“…The latter case is that of ordinary [12,25] and µ-meson and hyperon exotic atoms [26][27][28]. The Thomas and Larmor effects thoroughly determine the spin precession in agreement with the Bargmann-Michel-Telegdi equation [28,29].…”

“…For external Lorentz-vector potentials, the spin of the particles does experience torques which result in the socalled Larmor precession [25]. The latter case is that of ordinary [12,25] and µ-meson and hyperon exotic atoms [26][27][28]. The Thomas and Larmor effects thoroughly determine the spin precession in agreement with the Bargmann-Michel-Telegdi equation [28,29].…”

Extracting theΩ−electric quadrupole moment from lattice QCD data

“…A good illustration of this is the accuracy of the Ω − magnetic moment µ Ω − = −(2.019 ± 0.053)µ N [19][20][21][22], where µ N is the nuclear magneton. It is also expected that the Q Ω − quadrupole moment will be measured in a near future [23][24][25][26].…”