FIG 3
![(color online). Comparison of the hydrogen 1S-2S centroid frequency derived from the 1SðF ¼ 1Þ-2SðF ¼ 1Þ hyperfine component including the most recent November 2010 measurement [4,6,7]. Each black point represents a one-day average. The labeled red hollow points are the weighted mean values including systematic uncertainties. To measure the latter we also give 2 per degree of freedom (d.o.f.) of the computed average.](profile/Janis_Alnis/publication/258085880/figure/fig2/AS:613986097700870@1523397101293/color-online-Comparison-of-the-hydrogen-1S-2S-centroid-frequency-derived-from-the-1SdF.png)
(color online). Comparison of the hydrogen 1S-2S centroid frequency derived from the 1SðF ¼ 1Þ-2SðF ¼ 1Þ hyperfine component including the most recent November 2010 measurement [4,6,7]. Each black point represents a one-day average. The labeled red hollow points are the weighted mean values including systematic uncertainties. To measure the latter we also give 2 per degree of freedom (d.o.f.) of the computed average.
Source publication
We have measured the frequency of the extremely narrow 1S-2S two-photon transition in atomic hydrogen using a remote cesium fountain clock with the help of a 920 km stabilized optical fiber. With an improved detection method we obtain f1S-2S=2466 061 413 187 018 (11) Hz with a relative uncertainty of 4.5×10-15, confirming our previous measurement o...
Context in source publication
Context 1
... the current result is presented with the pre- vious and other measurements from 1999 [4] and 2003 [6] in Fig. 3. The new measurement is in good agreement with the measurement [7] made with a local cesium fountain clock but has almost a factor of 2 smaller statistical uncer- tainty (3.3 Hz) as shown in Figs. 2 and 3 due to the higher detection efficiency. As part of the search for a fundamental physical theory that can unify quantum mechanics and ...
Similar publications
We report on the detection of extremely narrow Feshbach resonances by employing a Mott-insulating state for cesium atoms in a three-dimensional optical lattice. The Mott insulator protects the atomic ensemble from high background three-body losses in a magnetic field region where a broad Efimov resonance otherwise dominates the atom loss in bulk sa...
Citations
... Experimentally, low-Z systems are studied using precision spectroscopy. The continuous development and ever-increasing precision of experimental methods facilitate increasingly stringent testing of theoretical calculations [26][27][28][29][30][31][32][33][34][35]. Ionization energies [35], and more generally, atomic transition frequencies [26,33,34] of light elements (e.g., H, He) can be determined with uncertainties as low as 10 −12 to 10 −15 E h . ...
... The continuous development and ever-increasing precision of experimental methods facilitate increasingly stringent testing of theoretical calculations [26][27][28][29][30][31][32][33][34][35]. Ionization energies [35], and more generally, atomic transition frequencies [26,33,34] of light elements (e.g., H, He) can be determined with uncertainties as low as 10 −12 to 10 −15 E h . ...
... in which the s 1 , s 2 and other factors in K ∆ depend on the E total energy, rendering Eq. (26) nonlinear in E. V ϵ carries the effect of (irreducible) pair, retardation, and radiative corrections, Figs. 3(d)-(m). ...
Precision physics aims to use atoms and molecules to test and develop the fundamental theory of matter, possibly beyond the Standard Model. Most of the atomic and molecular phenomena are described by the QED (quantum electrodynamics) sector of the Standard Model. Do we have the computational tools, algorithms, and practical equations for the most possible complete computation of atoms and molecules within the QED sector? What is the fundamental equation to start with? Is it still Schr\"odinger's wave equation for molecular matter, or is there anything beyond that? This paper provides a concise overview of the relativistic QED framework and recent numerical developments targeting precision physics and spectroscopy applications with common features with the robust and successful relativistic quantum chemistry methodology.
... Introduction. Precise transmission of frequency signals plays an important role in scientific research, especially in fields such as radio astronomy and fundamental physics [1][2][3]. In these scientific research facilities or other urban applications, the frequency transmission focus is on kilometer-scale distances, such as x ray free-electron lasers and intense laser beamlines [4], linear accelerator facility [5], remote microwave/RF transfer [6], stable microwave, and optical signal dissemination [7]. ...
We demonstrate an optical fiber-based, multiple-access frequency transmission using two optical frequency combs. The experimental results using the Allan deviation analysis show that with the phase compensation technique, the frequency instabilities at the remote site are 8.7 × 10⁻¹⁵/1 s and 1.0 × 10⁻¹⁷/10³ s, and at the accessing node along the fiber link, the frequency instabilities are 6.9 × 10⁻¹⁵/1 s and 1.1 × 10⁻¹⁷/10³ s. Similarly, the power spectral density of phase noise was analyzed in the frequency domain. These experimental results demonstrate that the compensation scheme improved the performance by two to three orders of magnitude. Thus, the proposed frequency transmission technique has potential application for disseminating ultrastable frequency references in the optical fiber network.
... As frequency standards have seenrapid improvements in stability over the past few decades, the ability to transfer a frequency reference from one location to another without degrading the signal has become of increasing interest in the frequency metrology community. Numerous applications arise from ultrastable frequency transfer, such as precision tests of fundamental physics, the development of long-baseline coherent radio telescope arrays, and proposals for new gravitational wave detectors [1][2][3][4][5][6][7]. Optical fiber is one of the most effective media used to distribute stable frequency standards over long distances [6,8]. ...
... Polarization mode dispersion also imposes feedback limits as light traveling in the forward and reverse directions may not have the same polarization and therefore propagate at different speeds [11]. However, to operate as closely as possible to the symmetry condition, the majority of previously demonstrated fiber links have been implemented on a single optical fiber [1][2][3]8,11,14,15,[18][19][20][21][22][24][25][26]28,29]. On one fiber, separating the incident and returning light poses complications as backreflections (including Rayleigh, Raman, and stimulated Brillouin scattering) are introduced that can degrade performance [30]. ...
We demonstrate the transfer of a cesium frequency standard steered to UTC(NIST) over 20 km of dark telecom optical fiber. Our dissemination scheme uses an active stabilization technique with a phase-locked voltage-controlled oscillator. Out-of-loop characterization of the optical fiber link performance is done with dual-fiber and single-fiber transfer schemes. We observe a fractional frequency instability of 1.5 × 10⁻¹² and 2 × 10⁻¹⁵ at averaging intervals of 1 s and 10⁵ s, respectively, for the link. Both schemes are sufficient to transfer the cesium clock reference without degrading the signal, with nearly an order of magnitude lower fractional frequency instability than the cesium clocks over all time scales. The simplicity of the two-fiber technique may be useful in future long-distance applications where higher stability requirements are not paramount, as it avoids technical complications involved with the single-fiber scheme.
... An extended QED theory of the line profile for many-electron atoms and highly charged ions (HCI) was described in [3], see also [4]. The development of the line profile theory is closely related to experimental advances in measuring the transition frequency in the hydrogen atom [5,6], where the 1s − 2s two-photon transition was measured with an accuracy of about 10 −15 relative magnitude. Such experiments have stimulated interest in theoretical studies of effects beyond the resonance approximation. ...
Modern resonance spectroscopic experiments on the measurement of transition frequencies in atoms have reached a level where a meticulous description of all aspects of the studied processes has become obligatory. The precision achieved has led to the fact that the determination of the transition frequency on the basis of measured data is substantially refined by theoretical treatment of the observed spectral line profile. Thus, a large impact of effects arising beyond the resonance approximation, in particular due to the effect of quantum interference, is found experimentally. We show that the picture becomes even more complicated when the observed spectral line profile is “identified” with one of the processes—emission or absorption. An accurate determination of the transition frequency requires a description of the absorption line profile inseparable from the emission process, and vice versa. The theoretical aspects discussed in this paper create prerequisites for more accurate experiments.
... Since the inception of the SME, there has been a recognition that the high precision attainable in atomic spectroscopy experiments made them favorable for detecting Lorentz violation [9,10]. Consequently, several experimental groups in this field designed experiments that imposed constraints on minimal SME coefficients [11][12][13][14][15][16][17][18][19][20][21]. ...
... Here, Δm F represents the change in the quantum number m F during the transition. Keep in mind that the sensitivity to the electron coefficients in (19) and (20) is proportional to the ratio δν exp =hjp e j k i of the experimental constraint on the frequency shift δν exp relative to the corresponding expectation value hjp e j k i. The expectation values hjp e j k i are nearly identical for hydrogen and deuterium. ...
... The situation is different for the proton coefficients contributing to the hydrogen and deuterium frequency shifts in (19) and (20), respectively. In the case of hydrogen, the sensitivity remains proportional to the ratio δν exp =hjp e j k i, where hjp e j 2 i ∼ 10 −11 GeV 2 and hjp e j 4 i ∼ 10 −23 GeV 4 . ...
This work presents a model for testing Lorentz and CPT symmetry through sidereal-variation studies of the hyperfine-Zeeman deuterium ground-state transition frequencies. It represents an advancement over previous models by using a well-established deuteron wave function parametrization to calculate contributions from nucleon Lorentz-violating operators toward the Lorentz-violating frequency shift. Furthermore, this work extends the analysis beyond the zeroth-boost order previously considered. This study centers on deuterium’s potential for testing Lorentz-violating nonminimal terms. Specifically, it compares the prospects of an ongoing deuterium experiment with the current best limits on nonminimal coefficients. The conclusion drawn is that the deuterium experiment holds the potential to enhance and establish first-time limits on nonminimal proton, neutron, and electron SME coefficients, marking it as a valuable experiment in the current worldwide systematic search for Lorentz and CPT violation.
... Fundamental physics tests in hydrogen [1][2][3][4][5] rely on determining two parameters; the Rydberg constant R ∞ , which relates the theoretical energy scale to the SI system of units, and the 'size' of the proton, characterized by its charge radius r p , which cannot yet be accurately calculated from quantum chromodynamics [6]. The 1S-2S transition frequency, which has been measured with a fractional uncertainty of ∼10 −15 [7,8], can be used to precisely determine one of these parameters, but must be complemented by measurements of other transitions or scattering-based measurements of r p [9]. It is well-known that the current dataset of relevant measurements is internally inconsistent [10,11], and inconsistent with measurements in muonic hydrogen [12]; a problem often called the 'proton charge radius puzzle' [13]. ...
... Currently, all precision H spectroscopy experiments rely on an atomic beam as the source [7,8,[14][15][16][17][18][19][20][21]. Line shifts and broadening due to motional (Doppler) effects are a significant source of uncertainty, and careful velocity filtering [7] and/or lineshape analysis (see the supplementary information of [14]) is required to extract precise measurements of the transition frequency. ...
... It is instructive to compare the results in table 3 to measurements in cold atomic beams [7,8]. The systematic uncertainty in beam measurements is dominated by velocity-dependent effects such as the second-order Doppler shift. ...
We consider the potential use of optical traps for precision measurements in atomic hydrogen (H). Using an implicit summation method, we calculate the atomic polarisability, the rates of elastic/inelastic scattering and the ionisation rate in the wavelength range 395 to 1000\,nm. We extend previous work to predict three new magic wavelengths for the 1S--2S transition. At the magic wavelengths, the 1S--2S transition is unavoidably and significantly broadened due to trap-induced ionisation associated with the high intensity required to trap the 1S state. However, we also find that this effect is partially mitigated by the low mass of H, which increases the trap frequency, enabling Lamb-Dicke confinement in shallow lattices. We find that a H optical lattice clock, free from the motional systematics which dominate in beam experiments, could operate with an intrinsic linewidth of the order of 1 kHz. Trap-induced losses are shown not to limit measurements of other transitions.
... The best measures transition we are aware of is the 1S − 2S transition, which theoretically corresponds to 10.2 eV. The experimentally measured value of this transition reads [42] f 1S−2S = 2466061413187018 ± 11 Hz =⇒ ∆E 1S−2S = 10.1988 ± O(10 −13 ) eV. (4.20) ...
A bstract
We provide the corrected calculation of the ( g − 2) μ in non-local QED previously done in the literature. In specific, we show the proper technique for calculating loops in non-local QED and use it to find the form factors F 1 ( q ² ) and F 2 ( q ² ) in non-local QED. We also utilize this technique to calculate some novel results in non-local QED, including calculating the correction to the photon self-energy, the modification to the classical Coulomb potential, the modification to the energy levels of the hydrogen atom, and the contribution to the Lamb shift. We also discuss charge dequantization through non-locality, and show that the experimental bounds on the electric charge on Dirac neutrinos, translate into strong flavor-dependent bounds on the scale on non-locality that range between 10 ⁵ − 10 ¹⁰ TeV. We also discuss the inconsistencies of unrenormalized non-local Quantum Field Theories (QFTs) and the need for renormalizing them, even when they are free from UV divergences.
... (iii) We exclude the input datum A7 (the 2013 measurement of the 1s 1/2 -2s 1/2 transition energy in electronic hydrogen [56]), in view of its strong correlation with the input datum A6 (the 2011 measurement of that transition). This strong correlation tends to inflate the value of χ 2 significantly in fits using both values. ...
We consider the impact of combining precision spectroscopic measurements made in atomic hydrogen with similar measurements made in atomic deuterium on the search for physics beyond the standard model. Specifically, we consider the wide class of models that can be described by an effective Yukawa-type interaction between the nucleus and the electron. We find that it is possible to set bounds on new light-mass bosons that are orders of magnitude more sensitive than those set using a single isotope only, provided the interaction couples differently to the deuteron and proton. Further enhancements of these bounds by an order of magnitude or more would be made possible by extending the current measurements of the isotope shift of the 1s1/2−2s1/2 transition frequency to that of a transition between the 2s1/2 state and a Rydberg s state.
... Forbidden transitions have been captive substantial interest across various fields. [1][2][3][4] Precision measurements of forbidden transitions have multiple applications, including probing fundamental physics, [5][6][7][8][9][10] developing frequency-standard metrology, [11][12][13][14] and searching for new physics beyond the standard models. [15] Moreover, these forbidden lines contribute significantly to diagnosing laboratory and astrophysical plasmas, [1,[16][17][18][19][20] since their intensities tend to be sensitive to the density or temperature of the plasma. ...
An experimental measurement of the lifetime of 3 d ⁹ ² D 3/2 metastable level in Mo ¹⁵⁺ is reported in this work. The Mo ¹⁵⁺ ions are produced and trapped in an electron beam ion trap with a magnetic field of 0.65 T. The decay photons emitted from 3 d ⁹ ² D 3/2 level are subsequently recorded via a cooled photomultiplier tube. Through meticulous scrutiny of potential systematic uncertainties affecting the measurement outcomes, we have determined the lifetime of Mo ¹⁵⁺ 3 d ⁹ ² D 3/2 metastable level to be 2.83(22) ms. The experimental result provide clear distinguishment from existing calculations based on various theoretical approaches.
... 3. We exclude the input datum A7 (the 2013 measurement of the 1s 1/2 -2s 1/2 transition energy in electronic hydrogen [51]), in view of its strong correlation with the input datum A6 (the 2011 measurement of that transition). This strong correlation tends to inflate the value of χ 2 significantly in fits using both values. ...
We consider the impact of combining precision spectroscopic measurements made in atomic hydrogen with similar measurements made in atomic deuterium on the search for physics beyond the Standard Model. Specifically we consider the wide class of models that can be described by an effective Yukawa-type interaction between the nucleus and the electron. We find that it is possible to set bounds on new light-mass bosons that are orders of magnitude more sensitive than those set using a single isotope only, provided the interaction couples differently to the deuteron and proton. Further enhancements of these bounds by an order of magnitude or more would be made possible by extending the current measurements of the isotope shift of the 1s$_{1/2}$-2s$_{1/2}$ transition frequency to that of a transition between the 2s$_{1/2}$ state and a Rydberg s-state.
