Physicists at CERN Just Discovered a Brand New Particle

And it lasts for a really long time!
Brad Bergan
An abstract depiction of elementary particle themes.agsandrew / iStock

In quantum physics, one breakthrough can quickly lead to several more.

This could happen in the wake of a brand new particle recently discovered by a group of scientists during the Large Hadron Collider beauty (LHCb) experiment, called Tcc+ and dubbed a tetraquark, according to a recent presentation at the European Physical Society Conference on High Energy Physics (EPS-HEP). The new particle is an exotic hadron comprised of two quarks and two antiquarks.

Crucially, this exotic matter particle lives longer than any other ever discovered, in addition to containing two heavy quarks and two light antiquarks, in another first.

CERN physicists discover the 'open charm' of a 'super' exotic hadron

All matter is comprised of fundamental building blocks, called quarks, which can fuse to form hadrons, including baryons, like the neutron and proton of conventional atomic theory. These contain three quarks, in addition to mesons, which come into being as quark-antiquark pairs. In the last several years, numerous "exotic" hadrons, particles dubbed as such because they possess four or five quarks (instead of two or three, which is more normal), were discovered. But the recent study has revealed the existence of an especially distinguished exotic hadron, or super-exotic hadron, if you can believe it.

The Large Hadron Collider beauty experiment focuses on analyzing the subtle differences between matter and antimatter, and involves the study of a specific kind of matter called the "beauty quark", or "b quark".

New Tetraparticle
An artist's impression of the new tetraquark. Source: CERN

The exceptionally unique hadron contains two charm quarks, in addition to both an up and a down antiquark. In recent years, multiple tetraquarks were discovered, one of which had two charm quarks, and two charm antiquarks. But the newly-discovered one has two charm quarks, without the extra two charm antiquarks that previously discovered hadrons had. Called "open charm", or "double open charm", these particles are different from other quarks that have an equal balance of quarks and antiquarks that cancel one another out (like a zero-sum game). But in the case of the new "super" exotic hadron (super quote not official), the charm number adds up to two, according to a report.

Most Popular

High precision mass could lead to groundbreaking observations

But there's more to this Tcc+ super exotic hadron than charm. It's also the first particle discovered that's a member of a category of tetraquarks with a pair of both light and heavy antiquarks. This class of particles decays via a transformation into a pair of mesons, each of which comes into being via one of the heavy and one of the light antiquarks. Some theoretical predictions predicate the mass of tetraquarks of this kind to be near the sum of masses of the two mesons. In other words, their masses are very close, which creates "difficulty" for decay processes. What this does is extend the lifetime of the particle, compared to other ones, which is why Tccis the longest-lived exotic hadron ever discovered in the history of quantum physics.

Everyone knows quantum theory is famously difficult to parse, but this discovery will open the door to the discovery of even more novel particles of this class. Ones that are heavier, with one or two charm quarks that are replaced with bottom quarks. The theorized particle with two bottom quarks should have a mass smaller than the sum of any two B mesons, which, in simpler terms, means decay will be extremely difficult: Lacking the ability to decay via strong interaction, heavier particles than the newly-discovered one would have a lifetime that's several orders of magnitude longer than any exotic hadron observed before. Finally, this novel Tccparticle exhibit an exceptional level of precision on its mass, and enable further studies of quantum numbers of the particle. With these, physicists will finally be able to observe effects on quantum levels that no one has successfully studied before.


Correction: An earlier version of this article suggested the new particle was discovered with the Large Hadron Collider. This has been corrected to reflect that it was discovered amid the Large Hadron Collider beauty experiment.

message circleSHOW COMMENT (1)chevron