https://biblio.ugent.be/publication/685594/file/1130605.pdf

Review of Particle Physics

I will first review the experimental limits placed on the oblique correction parameters S and T. Then, I will discuss how the value of S can be estimated for running and walking technicolor theories.

/pdf/estimation-of-oblique-electroweak-corrections-1puptfhw6n.pdf

Estimation of oblique electroweak corrections

https://bura.brunel.ac.uk/bitstream/2438/20604/1/FullText.pdf

Precision electroweak measurements on the Z resonance

This paper presents a review of the current state of the art in the research field of cold and ultracold molecules. It serves as an introduction to the focus issue of New Journal of Physics on Cold and Ultracold Molecules and describes new prospects for fundamental research and technological development. Cold and ultracold molecules may revolutionize physical chemistry and few-body physics, provide techniques for probing new states of quantum matter, allow for precision measurements of both fundamental and applied interest, and enable quantum simulations of condensed-matter phenomena. Ultracold molecules offer promising applications such as new platforms for quantum computing, precise control of molecular dynamics, nanolithography and Bose-enhanced chemistry. The discussion is based on recent experimental and theoretical work and concludes with a summary of anticipated future directions and open questions in this rapidly expanding research field.

/pdf/cold-and-ultracold-molecules-science-technology-and-4kdvs1psel.pdf

Cold and ultracold molecules: science, technology and applications

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

The amplitude of the parity-nonconserving transition between the 6 S and 7 S states of cesium was precisely measured with the use of a spin-polarized atomic beam. This measurement gives Im(E1 pnc )/β = −1.5935(56) millivolts per centimeter and provides an improved test of the standard model at low energy, including a value for the S parameter of −1.3(3) exp (11) theory . The nuclear spin-dependent contribution was 0.077(11) millivolts per centimeter; this contribution is a manifestation of parity violation in atomic nuclei and is a measurement of the long-sought anapole moment.

https://science.sciencemag.org/content/sci/275/5307/1759.full.pdf

Measurement of Parity Nonconservation and an Anapole Moment in Cesium

We have made an improved measurement of the parity-nonconserving electric-dipole transition amplitude between the 6S and 7S states of atomic cesium We obtain Im(EPNC)β=−1576(34) mV/cm, which is in good agreement with the predictions of the standard model and earlier less precise measurements This places more stringent constraints on alternatives to the standard model We also see the first evidence of a nuclear-spin-dependent contribution to atomic parity nonconservation The nuclear-spin dependence observed is in agreement with that predicted to arise from a nuclear anapole moment

Precision measurement of parity nonconservation in atomic cesium: A low-energy test of the electroweak theory.

We describe a cesium atomic beam (${10}^{14}$ atoms ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$, 6\ifmmode\times\else\texttimes\fi{}${10}^{16}$ atoms ${\mathrm{sr}}^{\mathrm{\ensuremath{-}}1}$ ${\mathrm{s}}^{\mathrm{\ensuremath{-}}1}$) spin polarized using light from two diode lasers. Of the atoms, 95% may be placed into either the 6${\mathit{S}}_{1/2}$(F,${\mathit{m}}_{\mathit{F}}$)=(3,3) or (4,4) state, with less than 2\ifmmode\times\else\texttimes\fi{}${10}^{\mathrm{\ensuremath{-}}4}$ of the atoms left in the depleted hyperfine level. The latter fraction rises linearly with atomic beam intensity because of reabsorption of light scattered during the optical pumping process. This and other effects limiting complete hyperfine pumping are discussed.

High-brightness, high-purity spin-polarized cesium beam.

We have observed the resonance line shape for a very weak atomic transition excited when an atomic beam intersects a strong standing-wave laser field. The line shape has a dramatic intensity-dependent distortion which is Doppler free and independent of the excitation rate. We have calculated the line shape predicted by optical Bloch equations that include a spatially varying ac Stark shift, and find good agreement with our experimental results.

Asymmetric line shapes for weak transitions in strong standing-wave fields.

We have developed and tested a laser heterodyne radiometer (LHR) for detecting methane leaks from upstream oil and gas infrastructure and landfills that uses the Sun as the signal light source, demonstrating here sensitivity sufficient to detect "super-emitter" leaks (>50kg/h, 1166 slm). Tracking optics follow the Sun during its apparent daily transit across the sky, and the system collects direct absorption data and optionally the 1f and 2f wavelength modulation spectroscopy (WMS) signals. The direct absorption data are processed in real time using a retrieval algorithm with a 5 s update rate to reveal the methane concentration versus altitude for each measurement line of sight. The 1f and 2f WMS signals are significantly non-intuitive because of the dramatic change in the methane lineshape as a function of pressure (altitude) but may ultimately provide useful information for leak localization. We describe herein modifications to the RF detection train and data collection system that allow faster and higher signal-to-noise ratio measurements. Preliminary results suggest that leaks giving rise to methane concentrations of the order of 500 ppm-m can be effectively detected-sensitivity similar to current satellites with more continuous temporal coverage and areal coverage of the order of 100s of km2 for relatively low cost. We outline a method of using an array of LHRs to localize the leak using lineshape information and tomographic reconstruction techniques that will be tested in future work.

B. P. Masterson

Papers

Measurement of Parity Nonconservation and an Anapole Moment in Cesium

Precision measurement of parity nonconservation in atomic cesium: A low-energy test of the electroweak theory.

High-brightness, high-purity spin-polarized cesium beam.

Asymmetric line shapes for weak transitions in strong standing-wave fields.

Development of a laser heterodyne radiometer for regional methane leak detection.