In a first, CERN scientists carry out laser cooling of Positronium

Subject: Science and tech

Section: Space technology

Context:

An international team of physicists from the Anti-hydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) collaboration has achieved a breakthrough by demonstrating the laser cooling of Positronium.

More on news:

Physicists representing 19 European and one India research groups announced this scientific achievement.
The experiment was performed at the European Organization for Nuclear Research, more popularly known as CERN, in Geneva.
This is an important precursor experiment to the formation of antiHydrogen and the measurement of Earth’s gravitational acceleration on antihydrogen in the AEgIS experiment.

Timeline:

It was formally accepted as a scientific experiment by CERN in 2008.
The setting up of the AEgIS experiment, its construction and commissioning continued through 2012 – 2016.
This comprised designing of the complex particle traps used to confine antiparticles, antiprotons and positrons.
In 2018, AEgIS became the first in the world to demonstrate the pulsed production of antihydrogen atoms.

About Positronium:

Positronium, comprising a bound electron ( e- ) and positron ( e+ ), is a fundamental atomic system.
Due to its very short life, it annihilates with a half life of 142 nano-seconds.
Its mass is twice the electron mass and enjoys the unique distinction of being a pure leptonic atom.
This hydrogen-like system, with halved frequencies for excitation, makes it a great contender for attempting laser cooling and thereby performing tests of fundamental theories in physics.
Experimentalists achieved laser cooling of Positronium atoms initially from ~380 Kelvin to ~170 Kelvin, and demonstrated the cooling in one dimension using a 70-nanosecond pulse of the alexandrite-based laser system.
This experiment will pave the way for performing spectroscopic comparisons required for the Quantum Electrodynamics (QED), the study of the light and its interaction with charged matter, and a possible degenerate gas of Positronium down the road.

Benefits of the Experiment:

According to CERN, the new scientific development will allow high-precision measurements of the properties and gravitational behavior of this exotic but simple matter–antimatter system, which could reveal newer physics.
It also allows the production of a positronium Bose–Einstein condensate, in which all constituents occupy the same quantum state.

About CERN:

European Organisation for Nuclear Research (CERN) is the world’s largest nuclear and particle physics laboratory.
It is situated in the North West suburbs of Geneva on the France-Swiss Border.
It has 22 member states, four associate member states (including India and Pakistan) and three International Organisations have observer status.
CERN operates the Large Hadron Collider (LHC) which is the world’s largest and most powerful particle accelerator.
It is associated with the discovery of the Higgs Boson which is popularly known as the God particle.
Indian scientists have been active in construction of the LHC in the areas of design, development and supply of hardware accelerator components, software development and deployment in the machine.
They also had played a significant role in the CMS (Compact Muon Experiment), one of the two large experiments that led to the discovery of the God particle.