40 research outputs found
Alignment-to-orientation conversion and nuclear quadrupole resonance
The role of alignment-to-orientation conversion (AOC) in nuclear quadrupole
resonance (NQR) is discussed. AOC is shown to be the mechanism responsible for
the appearance of macroscopic orientation in a sample originally lacking any
global polarization. Parallels are drawn between NQR and AOC in atomic physics.Comment: 4 pages, 3 figures, v2: reorganized, Appendix adde
Reevaluation of the role of nuclear uncertainties in experiments on atomic parity violation with isotopic chains
In light of new data on neutron distributions from experiments with
antiprotonic atoms [ Trzcinska {\it et al.}, Phys. Rev. Lett. 87, 082501
(2001)], we reexamine the role of nuclear-structure uncertainties in the
interpretation of measurements of parity violation in atoms using chains of
isotopes of the same element. With these new nuclear data, we find an
improvement in the sensitivity of isotopic chain measurements to ``new
physics'' beyond the standard model. We compare possible constraints on ``new
physics'' with the most accurate to date single-isotope probe of parity
violation in the Cs atom. We conclude that presently isotopic chain experiments
employing atoms with nuclear charges Z < 50 may result in more accurate tests
of the weak interaction.Comment: 6 pages, 1 fig., submitted to Phys. Rev.
Towards measuring nuclear-spin-dependent and isotopic-chain atomic parity violation in ytterbium
We discuss experiments aimed at measurements of atomic parity nonconservation
(PNC) effects in the 1S0-3D1 transition (408 nm) in atomic Ytterbium (Z=70).
According to theoretical predictions, the PNC-induced E1 amplitude of this
transition is ~100 times larger than the analogous amplitude in Cs. Such an
experiment will determine differences in PNC effects between different
hyperfine components for odd-neutron-number Yb isotopes and, thereby, will
allow measurements of the nuclear anapole moments in nuclei with unpaired
neutrons. In addition, measurements of PNC in different isotopes would give
information on neutron distributions within the nuclei. The apparatus designed
and built for this experiment is described, and results of measurements towards
understanding of systematic effects influencing the accuracy, and the current
status of the ongoing PNC measurements are presented
Analysis method for detecting topological defect dark matter with a global magnetometer network
© 2020The Global Network of Optical Magnetometers for Exotic physics searches (GNOME) is a network of time-synchronized, geographically separated, optically pumped atomic magnetometers that is being used to search for correlated transient signals heralding exotic physics. GNOME is sensitive to exotic couplings of atomic spins to certain classes of dark matter candidates, such as axions. This work presents a data analysis procedure to search for axion dark matter in the form of topological defects: specifically, walls separating domains of discrete degenerate vacua in the axion field. An axion domain wall crossing the Earth creates a distinctive signal pattern in the network that can be distinguished from random noise. The reliability of the analysis procedure and the sensitivity of the GNOME to domain-wall crossings are studied using simulated data11sciescopu