This Particle's Unusual Behavior is Hinting at Something Big
Particle Physics might finally solve a long-standing cosmology puzzle. For the first time, physicists have observed a new particle changing into an antiparticle and back again. The new particle is the charm meson, containing a charm quark and an anti-up quark.
2021-07-09 19:00:00 - Secrets of the Universe
For more than ten years, it was known that the charm mesons could travel as a mixture of their particle and antiparticle state. However, for the first time, they have been found to oscillate between the two states.
Furthermore, measurements have shown that these particles differ by 10^(-38) grams.
That's a hundred trillion trillion trillion times smaller than a gram. This negligible mass difference was measured with copious data and precise measurements.
In laboratory systems, charm meson particles are produced in proton-proton collisions in particle accelerators. Before decaying or transforming into other particles, they travel only a few millimeters.
The researchers compared the charm meson particles that decayed after traveling a short distance with those that travel a little further to measure the mass difference between the two classes of the particles.
Apart from the charm meson, only one particle has been seen to oscillate in this way; the strange beauty meson.
But what makes the discovery impressive is that in the case of charm mesons, the oscillation is very slow, making the transition extremely difficult to be measured within the short time of 40 picoseconds that the meson takes to decay. This discovery has opened up a new door for particle exploration.
It can potentially prove to be a significant step in solving the mystery of matter-antimatter asymmetry and shed some light on why our Universe is entirely made up of matter, even though matter and antimatter were created in equal amounts after the big bang.