This paper gives the 2010 self-consistent set of values of the basic constants and conversion factors of physics and chemistry recommended by the Committee on Data for Science and Technology (CODATA) for international use. The 2010 adjustment takes into account the data considered in the 2006 adjustment as well as the data that became available from 1 January 2007, after the closing date of that adjustment, until 31 December 2010, the closing date of the new adjustment. Further, it describes in detail the adjustment of the values of the constants, including the selection of the final set of input data based on the results of least-squares analyses. The 2010 set replaces the previously recommended 2006 CODATA set and may also be found on the World Wide Web at physics.nist.gov/constants.

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CODATA Recommended Values of the Fundamental Physical Constants: 2006

The development of wave optics for light brought many new insights into our understanding of physics, driven by fundamental experiments like the ones by Young, Fizeau, Michelson-Morley and others. Quantum mechanics, and especially the de Broglie’s postulate relating the momentum p of a particle to the wave vector k of an matter wave: k = 2 λ = p/ℏ, suggested that wave optical experiments should be also possible with massive particles (see table 1), and over the last 40 years electron and neutron interferometers have demonstrated many fundamental aspects of quantum mechanics [1].

/pdf/optics-and-interferometry-with-atoms-and-molecules-1vnuwajb51.pdf

Optics and interferometry with atoms and molecules

Determination of the gravitational constant G using laser-cooled atoms and quantum interferometry, a technique that gives new insight into the systematic errors that have proved elusive in previous experiments, yields a value that has a relative uncertainty of 150 parts per million and which differs from the current recommended value by 1.5 combined standard deviations. The Newtonian gravitational constant G, also known as the universal gravitational constant or 'big G', is a fundamental physical constant that is used in the calculation of gravitational attraction between two bodies. There are several ways to measure G with high precision, but these measurements disagree, presumably because of the intervention of unknown errors in the different experiments. With the aim of identifying and ultimately removing the systematic errors that give rise to these discrepancies, Gabriele Rosi and colleagues have carried out a high-precision measurement of G using quantum interferometry with laser-cooled atoms, an experimental approach that differs radically from previous determinations. The authors obtain a value for G with a precision of ∼0.015% — approaching that of the traditional measurements, and with prospects for considerable further improvement. Although this result doesn't yet solve the problem of the discrepant measurements, the use of such a radically different technique holds promise for identifying the systematic errors that have plagued previous determinations. About 300 experiments have tried to determine the value of the Newtonian gravitational constant, G, so far, but large discrepancies in the results have made it impossible to know its value precisely1. The weakness of the gravitational interaction and the impossibility of shielding the effects of gravity make it very difficult to measure G while keeping systematic effects under control. Most previous experiments performed were based on the torsion pendulum or torsion balance scheme as in the experiment by Cavendish2 in 1798, and in all cases macroscopic masses were used. Here we report the precise determination of G using laser-cooled atoms and quantum interferometry. We obtain the value G = 6.67191(99) × 10−11 m3 kg−1 s−2 with a relative uncertainty of 150 parts per million (the combined standard uncertainty is given in parentheses). Our value differs by 1.5 combined standard deviations from the current recommended value of the Committee on Data for Science and Technology3. A conceptually different experiment such as ours helps to identify the systematic errors that have proved elusive in previous experiments, thus improving the confidence in the value of G. There is no definitive relationship between G and the other fundamental constants, and there is no theoretical prediction for its value, against which to test experimental results. Improving the precision with which we know G has not only a pure metrological interest, but is also important because of the key role that G has in theories of gravitation, cosmology, particle physics and astrophysics and in geophysical models.

/pdf/precision-measurement-of-the-newtonian-gravitational-3baybd7a0j.pdf

Precision measurement of the Newtonian gravitational constant using cold atoms

Measurements of the fine-structure constant α require methods from across subfields and are thus powerful tests of the consistency of theory and experiment in physics. Using the recoil frequency of cesium-133 atoms in a matter-wave interferometer, we recorded the most accurate measurement of the fine-structure constant to date: α = 1/137.035999046(27) at 2.0 × 10 −10 accuracy. Using multiphoton interactions (Bragg diffraction and Bloch oscillations), we demonstrate the largest phase (12 million radians) of any Ramsey-Borde interferometer and control systematic effects at a level of 0.12 part per billion. Comparison with Penning trap measurements of the electron gyromagnetic anomaly g e − 2 via the Standard Model of particle physics is now limited by the uncertainty in g e − 2; a 2.5σ tension rejects dark photons as the reason for the unexplained part of the muon’s magnetic moment at a 99% confidence level. Implications for dark-sector candidates and electron substructure may be a sign of physics beyond the Standard Model that warrants further investigation.

https://science.sciencemag.org/content/sci/360/6385/191.full.pdf

Measurement of the fine-structure constant as a test of the Standard Model

We measured the Newtonian constant of gravity, G , using a gravity gradiometer based on atom interferometry. The gradiometer measures the differential acceleration of two samples of laser-cooled Cs atoms. The change in gravitational field along one dimension is measured when a well-characterized Pb mass is displaced. Here, we report a value of G = 6.693 × 10–11 cubic meters per kilogram second squared, with a standard error of the mean of ±0.027 × 10–11 and a systematic error of ±0.021 × 10–11 cubic meters per kilogram second squared. The possibility that unknown systematic errors still exist in traditional measurements makes it important to measure G with independent methods.

https://science.sciencemag.org/content/sci/315/5808/74.full.pdf

Atom Interferometer Measurement of the Newtonian Constant of Gravity

We report the demonstration of a sensitive absolute-gravity gradiometer based on light-pulse atom-interference techniques. The gradiometer consists of two absolute accelerometers operated in a differential mode. We report a differential acceleration sensitivity of $4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}g/{\mathrm{Hz}}^{1/2}$ and an inferred differential acceleration accuracy of less than ${10}^{\ensuremath{-}9}g.$ This corresponds to a gravity-gradient sensitivity of $4E/{\mathrm{Hz}}^{1/2}$ ${(1E=10}^{\ensuremath{-}9}{\mathrm{s}}^{\mathrm{\ensuremath{-}}2})$ and an accuracy of better than $1E$ for a 10-m separation between accelerometers. We demonstrate that the instrument can be used to detect nearby masses in a vibrationally noisy environment and characterize instrument sensitivity to spurious acceleration and rotation noise.

https://arxiv.org/pdf/physics/0105088.pdf

Sensitive absolute-gravity gradiometry using atom interferometry

We present a method of analysis involving ellipse-specific fitting of sinusoidally coupled data from two gravimeters in a gradiometer configuration. This method permits rapid extraction of induced gradient phase shifts in the presence of common-mode vibrational phase noise. Gravity gradients can be accurately measured in the presence of large vibrational accelerations.

Method of phase extraction between coupled atom interferometers using ellipse-specific fitting

We have demonstrated a new technique for detecting ultracold atoms. A balanced detection technique was used to reduce laser-induced detection noise in conjunction with modulation-transfer spectroscopy to distinguish cold atoms from a thermal cloud. Using this technique, we have achieved signal-to-noise ratios in excess of 2000:1.

Low-noise detection of ultracold atoms.

We report on the progress in the development of high sensitivity and accuracy inertial force sensors which are based on atom interference techniques.

J. B. Fixler

Papers

Sensitive absolute-gravity gradiometry using atom interferometry

Method of phase extraction between coupled atom interferometers using ellipse-specific fitting

Low-noise detection of ultracold atoms.

Atom interferometer inertial force sensors