arXiv| We search for transient variations of the fine structure constant using data from a European network of fiber-linked optical atomic clocks. This analysis also presents a possibility to search for dark matter, the mysterious substance hypothesised to explain galaxy dynamics and other astrophysical phenomena that is thought to dominate the matter density of the universe.Read More
arXiv| We perform high-precision calculations of the hyperfine structure for n 2S_1/2 and n 2P_1/2 states of the alkali-metal atoms Rb, Cs, and Fr across principal quantum number n, and studied the trend in the size of the correlations.Read More
Phys.Rev.A| We employ a technique that combines the configuration interaction method with the singles-doubles coupled-cluster method to perform calculation of the energy levels, transition amplitudes, lifetimes, g-factors, and magnetic dipole and electric quadrupole hyperfine structure constants for many low-lying states of neutral actinium.Read More
We investigate the possibility for the direct detection of low mass (GeV scale) WIMP dark matter in scintillation experiments. Such WIMPs are typically too light to leave appreciable nuclear recoils, but may be detected via their scattering off atomic electrons…Read More
We discuss the theoretical analysis and interpretation of space-time separated clock experiments in the context of a space-time varying scalar field that is non-universally coupled to the standard model fields…Read More
Phys. Rev. D| By analyzing the satellite and terrestrial atomic clock data, it is possible to search for transient signatures of exotic physics, such as "clumpy" dark matter and dark energy, effectively transforming the GPS constellation into a 50,000 km aperture sensor array.Read More
arXiv:1803.00617| Dark matter may induce an asymmetry in the noise distribution of precision measurement devices. A search based on this technique would extend the discovery reach for certain models beyond that of existing experiments by many orders of magnitude.Read More
Nature Communications (open access): Mining 16 years of archival GPS data, we find no evidence for DM clumps in the form of domain walls. This enables us to improve limits on DM couplings to atomic clocks by several orders of magnitude. Our work demonstrates the use of a global network of precision measurement devices in the search for DM.Read More
Phys. Rev. D We revisit the WIMP-type dark matter scattering on electrons that results in atomic ionization, and can manifest itself in a variety of existing direct-detection experiments.
While we find that the modulation fraction of all events with energy deposition above 2 keV in NaI can be quite significant, reaching ~50%, the relevant parts of the parameter space are excluded by the XENON10 and XENON100 experiments.
Phys. Rev. Lett. Atoms and molecules can become ionized during the scattering of a slow, heavy particle off a bound electron. Such an interaction involving leptophilic weakly interacting massive particles (WIMPs) is a promising possible explanation for the anomalous 9 sigma annual modulation in the DAMA dark matter direct detection experiment. We also show that electron relativistic effects actually give the dominant contribution to such a process, meaning that nonrelativistic calculations may greatly underestimate the cross section.Read More
PATRAS 2015, Universidad de Zaragoza, Spain11th Patras Workshop on Axions, WIMPs and WISPs Talk: Axion and WIMP phenomena in atomic systems Talk: New Effects of Dark Matter which are Linear in the Interaction Strength (on behalf of Victor Flambaum) Poster: Axion Dark Matter: New atomic detection schemes
The Ultra-Light Frontier, Mainz Institute for Theoretical Physics, Johannes Gutenberg University, Mainz, Germany Talk: Axion-induced EDMs in paramagnetic systems
SSP 2015, Victoria BC, Canada 6th International Symposium on Symmetries in Subatomic Physics Talk: Atomic Methods for Dark Matter Detection Poster: Axion Dark Matter: New atomic detection schemes Poster: Atomic Symmetry Violation: New applications for tests of fundamental physics
- B. M. Roberts, Y. V. Stadnik, V. A. Dzuba, V. V. Flambaum, N. Leefer, and D. Budker, New Atomic Methods for Dark Matter Detection, J. Phys. Conf. Ser. 635, 022033 (2015) [Open Access].
- V. V. Flambaum, V. A. Dzuba, M. Pospelov, A. Derevianko, and B. M. Roberts, Atomic Ionization by Dark Matter Particles, J. Phys. Conf. Ser. 635, 022012 (2015) [Open Access].
- B. M. Roberts, Y. V. Stadnik, V. V. Flambaum, and V. A. Dzuba, Searching for Axion Dark Matter in Atoms: Oscillating Electric Dipole Moments and Spin-Precession Effects, Proceedings of the 11th PATRAS Workshop on Axions, WIMPs and WISPs (2015), [arXiv:1511.04098].
- Y. V. Stadnik, B. M. Roberts, V. V. Flambaum, and V. A. Dzuba, Searching for Scalar Dark Matter in Atoms and Astrophysical Phenomena: Variation of Fundamental Constants, Proceedings of the 11th PATRAS Workshop on Axions, WIMPs and WISPs (2015), [arXiv:1511.04100].
Ann. Rev. Nuc. Part. Sci.: Studying the violation of parity and time-reversal invariance in atomic systems has proven to be a very effective means for testing the electroweak theory at low energy and searching for physics beyond it. We review the recent progress in the field of parity and time-reversal violation in atoms, molecules, and nucleiRead More
Phys. Rev. D. We propose methods and present calculations that can be used to search for evidence of cosmic fields by investigating the parity-violating effects, including parity nonconservation amplitudes and electric dipole moments, that they induce in atoms.Read More
Phys. Rev. D We derive the relativistic factor for splitting of the g-factors of a fermion and its anti-fermion partner, which is important for placing constraints on dimension-five, CPT-odd and Lorentz-invariance-violating interactions from experiments performed in a cyclotron. From existing data, we extract limits (1σ) on the coupling strengths..Read More
Phys. Rev. Lett. We propose methods for extracting limits on the strength of P-odd interactions of pseudoscalar and pseudovector cosmic fields with electrons, protons and neutrons, by exploiting the static and dynamic parity-nonconserving amplitudes and electric dipole moments they induce in atoms. Candidates for such fields are dark matter (including axions)..Read More