high_energy_physics (2)

Neutrons Eye COVID...

CCJulAug20_NEUTRON_frontis.jpg

An eye for structure The LADI instrument at the ILL, a quasi-Laue neutron diffractometer used for single-crystal studies of biological macromolecules at high resolution. Neutron Laue diffraction patterns are recorded on a cylindrical detector, allowing the determination of protein structures including the locations of hydrogen/deuterium atoms. Credit: R Cubitt

Topics: COVID-19, High Energy Physics, Neutrons, Particle Physics

Advanced neutron facilities such as the Institut Laue-Langevin are gearing up to enable a deeper understanding of the structural workings of SARS-CoV-2.

The global scientific community has mobilized at an unprecedented rate in response to the COVID-19 pandemic, beyond just pharmaceutical and medical researchers. The world’s most powerful analytical tools, including neutron sources, harbor the unique ability to reveal the invisible, structural workings of the virus – which will be essential to developing effective treatments. Since the outbreak of the pandemic, researchers worldwide have been using large-scale research infrastructures such as synchrotron X-ray radiation sources (CERN Courier May/June 2020 p29), as well as cryogenic electron microscopy (cryo-EM) and nuclear magnetic resonance (NMR) facilities, to determine the 3D structures of proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which can lead to COVID-19 respiratory disease, and to identify potential drugs that can bind to these proteins in order to disable the viral machinery. This effort has already delivered a large number of structures and increased our understanding of what potential drug candidates might look like in a remarkably short amount of time, with the number increasing each week.

Neutron sources join the fight against COVID-19Matthew Blakeley, and Helmut Schober Institut Laue-Langevin.

Read more…
Left, schematics of the apparatus (positron beam, collimators, SiN gratings and emulsion detector. A HpGe detector is used as beam monitor). Right, single-particle interference visibility as a function of the positron energy is in agreement with quantum mechanics (blue) and disagrees with classical physics (orange dashed). Courtesy: Politecnico di Milano

 

Topics: Antimatter, High Energy Physics, Particle Physics, Quantum Mechanics


Researchers in Italy and Switzerland have performed the first ever double-slit-like experiment on antimatter using a Talbot-Lau interferometer and a positron beam.

The classic double-slit experiment confirmed that light and matter have the characteristics of both waves and particles, a duality that was first put forward by de Broglie in 1923. This superposition principle is one of the main postulates of quantum mechanics and researchers have since been able to diffract and interfere matter waves of objects of increasing complexity – from electrons to neutrons and molecules.

The QUPLAS (QUantum Interferometry and Gravitation with Positrons and LAsers) collaboration, which includes researchers from the Politecnico di Milano L-NESS in Como, the Milan unit of the Istituto Nazionale di Fisica Nucleare (INFN), the Università degli Studi di Milano and the University of Bern, has now performed the first interference experiment on positrons – the antimatter equivalent of electrons.

“The experiment was first proposed for electrons by Albert Einstein and Richard Feynman as a thought experiment and realized by Merli, Missiroli and Pozzi in 1976 and more systematically by Tonomura and colleagues in 1989,” explains QUPLAS spokesman Marco Giammarchi of the INFN. “In this original experiment, which was voted by Physics World as the most beautiful experiment, the researchers demonstrated the specifically quantum effect of single particle interference, which – according to Feynman – is the central ‘mystery’ of quantum theory.”

 

Antimatter quantum interferometry makes its debut, Belle Dumé, Physics World

Read more…