Investigation of ac Stark shifts in excited states of dysprosium relevant to testing fundamental symmetries

Weber, Carsten; Leefer, N.; Budker, Dmitry

doi:10.1103/physreva.88.062503

Cited by 6 publications

(4 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The temperature dependence of the transition frequencies has been measured near room temperature to be +29(4) mHz/K and −34(4) mHz/K for 164 Dy and 162 Dy, respectively. The isotopic dependence of the sign is consistent with BBR induced Stark shifts, but the attribution of these shifts to BBR is preliminary [29]. Currently, the 2 K temperature stability of the interaction region is used to estimate the systematic uncertainty due to this effect.…”

mentioning

confidence: 75%

New Limits on Variation of the Fine-Structure Constant Using Atomic Dysprosium

et al. 2013

Self Cite

View full text Add to dashboard Cite

We report on the spectroscopy of radio-frequency transitions between nearly degenerate, opposite-parity excited states in atomic dysprosium (Dy). Theoretical calculations predict that these states are very sensitive to variation of the fine-structure constant α owing to large relativistic corrections of opposite sign for the opposite-parity levels. The near degeneracy reduces the relative precision necessary to place constraints on variation of α, competitive with results obtained from the best atomic clocks in the world. Additionally, the existence of several abundant isotopes of Dy allows isotopic comparisons that suppress common-mode systematic errors. The frequencies of the 754-MHz transition in 164Dy and 235-MHz transition in 162Dy are measured over the span of two years. The linear variation of α is α·/α=(-5.8±6.9([1σ]))×10(-17) yr(-1), consistent with zero. The same data are used to constrain the dimensionless parameter kα characterizing a possible coupling of α to a changing gravitational potential. We find that kα=(-5.5±5.2([1σ]))×10(-7), essentially consistent with zero and the best constraint to date.

show abstract

mentioning

confidence: 75%

New Limits on Variation of the Fine-Structure Constant Using Atomic Dysprosium

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…(14) could be tested against an experiment. The clarification of the parity-breaking admixture terms also is important for other precision measurements in atomic physics which involve metastable states, such as EDM and weakinteraction experiments [42][43][44][45][46][47]. The fully retarded expression for the mixing term, given in Eq.…”

Section: −4mentioning

confidence: 99%

Long-range atom-wall interactions and mixing terms: Metastable hydrogen

Jentschura

2015

Phys. Rev. A

View full text Add to dashboard Cite

We investigate the interaction of metastable 2S hydrogen atoms with a perfectly conducting wall, including parity-breaking S-P mixing terms (with full account of retardation). The neighboring 2P 1/2 and 2P 3/2 levels are found to have a profound effect on the transition from the short-range, nonrelativistic regime, to the retarded form of the Casimir-Polder interaction. The corresponding P state admixtures to the metastable 2S state are calculated. We find the long-range asymptotics of the retarded Casimir-Polder potentials and mixing amplitudes, for general excited states, including a fully quantum electrodynamic treatment of the dipole-quadrupole mixing term. The decay width of the metastable 2S state is roughly doubled even at a comparatively large distance of 918 atom units (Bohr radii) from the perfect conductor. The magnitude of the calculated effects is compared to the unexplained Sokolov effect. , research on related matters has found continuously growing interest over the last decades [5][6][7][8]. In the non-retarded regime (close range), the interaction energy scales as 1/Z 3 with the atom-wall distance Z, while for atom-wall distances large in comparison to a typical atomic wavelength, the interaction energy scales as 1/Z 4 (see Chap. 8 of Ref.[9]). The leading term is given by virtual dipole transitions, while multipole corrections have recently been analyzed in Ref. [10]. The symmetry breaking induced by the wall leads to dipole-quadrupole mixing terms, which lead to admixtures to metastable levels [11,12]. While this effect has been analyzed in the non-retarded van-der-Waals regime [11,12], a fully quantum electrodynamic calculation of this effect would be of obvious interest. This fact is emphasized by the curious observation of a long-range, and conceivably super-long-range (micrometer-scale) interaction of metastable hydrogen 2S atoms with a conducting surface (the so-called Sokolov effect, see Refs. [13][14][15][16]). It is not far-fetched to suspect that this effect could be due to a quantum electrodynamically induced tail of the dipole-quadrupole mixing term in the atom-wall interaction. Namely, for the hydrogen 2S atom, the neighboring 2P 1/2 and 2P 3/2 levels are removed only by the Lamb shift and finestructure, respectively, while it is known that virtual states of lower energy can induce long-range tails in atomwall interactions, as well as in the Lamb shift between plates (see Refs. [17][18][19][20][21][22][23][24][25][26]). The large admixtures typically induced in atomic systems when a metastable level couples to nearly degenerate states of opposite parity suggest that a closer investigation of the hydrogen system is warranted. Atomic units with = 4πǫ 0 = 1 and c = 1/α are used throughout this Rapid Communication, where α is the fine-structure constant. The electron charge is explicitly denoted as e unless stated otherwise.Retardation of the atom-wall interaction.-The quan-

show abstract

“…2, and more details can be found in Refs. [42,43]. The optimal statistical precision is σ ν = γ/(2π Ṅ τ ), where γ/(2π) ≈ 20 kHz is the natural linewidth of the transition (see bottom panel of Fig.…”

mentioning

confidence: 99%

Search for Ultralight Scalar Dark Matter with Atomic Spectroscopy

Tilburg¹,

Leefer²,

Bougas³

et al. 2015

Phys. Rev. Lett.

239

284

View full text Add to dashboard Cite

We report new limits on ultralight scalar dark matter (DM) with dilaton-like couplings to photons that can induce oscillations in the fine-structure constant α. Atomic dysprosium exhibits an electronic structure with two nearly degenerate levels whose energy splitting is sensitive to changes in α. Spectroscopy data for two isotopes of dysprosium over a two-year span is analyzed for coherent oscillations with angular frequencies below 1 rad s −1 . No signal consistent with a DM coupling is identified, leading to new constraints on dilaton-like photon couplings over a wide mass range. Under the assumption that the scalar field comprises all of the DM, our limits on the coupling exceed those from equivalence-principle tests by up to 4 orders of magnitude for masses below 3 · 10 −18 eV. Excess oscillatory power, inconsistent with fine-structure variation, is detected in a control channel, and is likely due to a systematic effect. Our atomic spectroscopy limits on DM are the first of their kind, and leave substantial room for improvement with state-of-the-art atomic clocks.Dark matter (DM) makes up the majority of matter density in our Universe. Its ubiquitous abundance can be measured through its gravitational influence, but little is known about the microphysical properties of the DM particle(s), such as the mass, spin, and any nongravitational interactions. If the DM is bosonic rather than fermionic, it can have a sub-eV mass and such high occupation numbers that it acts more like a classical wavewith frequency equal to its mass-than a particle. Light bosonic dark matter has a natural production mechanism, namely early-universe misalignment of the field relative to the minimum of its potential [1][2][3]. Several motivated candidates in this category exist in the literature, most notably the QCD axion [4-6] and other axion-like particles, which, as parity-odd pseudo-Nambu-Goldstone bosons (PNGBs) of compact symmetry groups, primarily have derivative interactions with matter [7]. Light, parity-even bosons may also arise as PNGBs of noncompact groups such as those of scale, conformal, or shift symmetries, the most famous examples of which are dilatons [8][9][10]. Small explicit breakings of these symmetries may induce nonderivative operators for the scalar fields, such as mass terms and higher-dimensional operators coupling them to matter.We focus on ultralight scalar fields φ with couplings to the (square of the) electromagnetic field tensor F µν :where κ ≡ √ 4πG N , G N is Newton's constant, and e ≈ 0.303 is the electromagnetic gauge coupling (we use units in which = c = 1). The interaction is normalized such that d e = 1 yields an attractive force of gravitational strength between electromagnetic energy densities at distances smaller than the inverse mass (r m and naturalness considerations together suggest a minimum mass-squared for φ. However, given the existing hierarchy problems of the Standard Model, we remain agnostic to this issue and consider the full m φ -d e parameter space (see Ref.[13] for more discuss...

show abstract

Investigation of ac Stark shifts in excited states of dysprosium relevant to testing fundamental symmetries

Cited by 6 publications

References 36 publications

New Limits on Variation of the Fine-Structure Constant Using Atomic Dysprosium

New Limits on Variation of the Fine-Structure Constant Using Atomic Dysprosium

Long-range atom-wall interactions and mixing terms: Metastable hydrogen

Search for Ultralight Scalar Dark Matter with Atomic Spectroscopy

Contact Info

Product

Resources

About