13 research outputs found
Pinning down electron correlations in RaF via spectroscopy of excited states
We report the spectroscopy of 11 electronic states in the radioactive
molecule radium monofluoride (RaF). The observed excitation energies are
compared with state-of-the-art relativistic Fock-space coupled cluster (FS-RCC)
calculations, which achieve an agreement of >99.71% (within ~8 meV) for all
states. High-order electron correlation and quantum electrodynamics corrections
are found to be important at all energies. Establishing the accuracy of
calculations is an important step towards high-precision studies of these
molecules, which are proposed for sensitive searches of physics beyond the
Standard Model.Comment: Submitted for publicatio
The freeze-drying of pharmaceuticals in vials nested in a rack system. – Part II: Primary drying behaviour
The distribution of biopharmaceuticals often requires lyophilisation. The drug product is first frozen and potentially exposed to stress conditions that can be detrimental to its quality. These stresses are also encountered when a drug product has to be distributed under ultra-cold conditions. Adjusting the formulation and/or freezing conditions allows for limiting the impact of these stresses on the final product. This paper investigates two loading configurations, vials directly resting on the shelf and nested in a rack system, and their impact on the freezing and drying behaviour of a sucrose-based formulation. First, two key freezing parameters, i.e., ice nucleation temperature and cooling rate, were studied as they can affect the product behaviour during drying. The product freezing rate and the ice nucleation temperature distribution were affected by the loading configuration, resulting in larger ice crystals in the case of vials nested in a rack system. The analysis was also extended to the drying phase, showing that the loading configuration impacted the product temperature during drying and the overall heat transfer coefficient between the equipment and the product
Compatibility studies with pharmaceutical excipients for aripiprazole–heptakis (2,6-di-O-methyl)-β-cyclodextrin supramolecular adduct
Observation of the distribution of nuclear magnetization in a molecule
Rapid progress in the experimental control and interrogation of molecules, combined with developments in precise calculations of their structure, are enabling new opportunities in the investigation of nuclear and particle physics phenomena. Molecules containing heavy, octupole-deformed nuclei such as radium are of particular interest for such studies, offering an enhanced sensitivity to the properties of fundamental particles and interactions. Here, we report precision laser spectroscopy measurements and theoretical calculations of the structure of the radioactive radium monofluoride molecule, RaF. Our results allow fine details of the short-range electron-nucleus interaction to be revealed, indicating the high sensitivity of this molecule to the distribution of magnetization, currently a poorly constrained nuclear property, within the radium nucleus. These results provide a direct and stringent test of the description of the electronic wavefunction inside the nuclear volume, highlighting the suitability of these molecules to investigate subatomic phenomena
Observation of the distribution of nuclear magnetization in a molecule
International audienceRapid progress in the experimental control and interrogation of molecules, combined with developments in precise calculations of their structure, are enabling new opportunities in the investigation of nuclear and particle physics phenomena. Molecules containing heavy, octupole-deformed nuclei such as radium are of particular interest for such studies, offering an enhanced sensitivity to the properties of fundamental particles and interactions. Here, we report precision laser spectroscopy measurements and theoretical calculations of the structure of the radioactive radium monofluoride molecule, RaF. Our results allow fine details of the short-range electron-nucleus interaction to be revealed, indicating the high sensitivity of this molecule to the distribution of magnetization, currently a poorly constrained nuclear property, within the radium nucleus. These results provide a direct and stringent test of the description of the electronic wavefunction inside the nuclear volume, highlighting the suitability of these molecules to investigate subatomic phenomena
Precision spectroscopy and laser-cooling scheme of a radium-containing molecule
International audienceMolecules containing heavy radioactive nuclei are predicted to be extremely sensitive to violations of the fundamental symmetries of nature. The nuclear octupole deformation of certain radium isotopes massively boosts the sensitivity of radium monofluoride molecules to symmetry-violating nuclear properties. Moreover, these molecules are predicted to be laser coolable. Here we report measurements of the rovibronic structure of radium monofluoride molecules, which allow the determination of their laser cooling scheme. We demonstrate an improvement in resolution of more than two orders of magnitude compared to the state of the art. Our developments allowed measurements of minuscule amounts of hot molecules, with only a few hundred per second produced in a particular rotational state. The combined precision and sensitivity achieved in this work offer opportunities for studies of radioactive molecules of interest in fundamental physics, chemistry and astrophysics
Pinning down electron correlations in RaF via spectroscopy of excited states
International audienceWe report the spectroscopy of 11 electronic states in the radioactive molecule radium monofluoride (RaF). The observed excitation energies are compared with state-of-the-art relativistic Fock-space coupled cluster (FS-RCC) calculations, which achieve an agreement of >99.71% (within ~8 meV) for all states. High-order electron correlation and quantum electrodynamics corrections are found to be important at all energies. Establishing the accuracy of calculations is an important step towards high-precision studies of these molecules, which are proposed for sensitive searches of physics beyond the Standard Model