Physicists from CERN and the University of Tokyo have achieved a significant advancement in understanding the characteristics of positronium, a fleeting and unstable particle.

In a successful experiment, the AEgIS collaboration, using a laser tailored for the task, managed to decrease the temperature of a positronium cloud by over 50%.

Positronium is a unique particle system comprising an electron and its antiparticle, the positron.

Simultaneously, a team led by physicist Kenji Shu at the High Energy Accelerator Research Organization in Japan, affiliated with the University of Tokyo, achieved a temperature reduction of a positronium cloud to around a Kelvin (-272 °C).

This reduction effectively slows down the overall speed and distribution of electron and positron velocities.

Positronium, being the lightest known particle system, is highly unstable.

The inherent nature of matter and antimatter causes them to annihilate each other, producing a burst of radiation, Science Alert reported.

Positronium self-annihilates within an incredibly brief time frame of 142 billionths of a second, generating gamma rays.

Positronium, when created for experimental studies, exhibits a wide range of velocities, making precise measurements challenging.

Cooling down positronium is a potential solution to slow its particles, enabling more accurate property measurements.

Laser cooling, a method based on particles absorbing and emitting photons, was employed in this experiment.

When a particle absorbs a photon, it gains energy, and when it emits the photon, it loses energy.

Written by B.C. Begley