CERN found a new meson called toponium.

"This illustration shows toponium, made of a top-antitop pair of quarks, bound together into a meson rather than the (more typical) situation where they decay away before forming a bound state. Toponium wasn't initially expected, but observations from the CMS and ATLAS collaboration have revealed evidence for such a bound state, showing that it very likely does exist. Can the top quark, the shortest-lived particle of all, bind with anything else? Yes it can! New results at the LHC demonstrate toponium exists." (BigThink, The top quark isn’t a loner after all: “toponium” is real!)

In normal conditions. Electrons. And composite particles protons and neutrons form atoms. In a simplified model, two up and one down quark form the proton. Two down and one up quark form a neutron. The lifetime of a neutron is about 14 minutes and 40 seconds. The reason for that is that energy travels from the down quarks to the up quark and that forms a reflection or standing wave that destroys the neutron. The lifetime of a proton is not known. Protons and neutrons are hadrons. A  hadron that involves three quarks is called a baryon. 

"In particle physics, a baryon is a type of composite subatomic particle that contains an odd number of valence quarks, conventionally three. Protons and neutrons are examples of baryons; because baryons are composed of quarks, they belong to the hadron family of particles. Baryons are also classified as fermions because they have half-integer spin." (Wikipedia, Baryons)

The name "baryon", introduced by Abraham Pais, comes from the Greek word for "heavy", because, at the time of their naming, most known elementary particles had lower masses than the baryons. Each baryon has a corresponding antiparticle (antibaryon) where their corresponding antiquarks replace quarks. For example, a proton is made of two up quarks and one down quark; and its corresponding antiparticle, the antiproton, is made of two up antiquarks and one down antiquark." (Wikipedia, Baryons)

Sometimes hadrons involve more or less, than than three quarks. Those hadrons are known as mesons. Unlike baryons, mesons' existence is very short. And the reason for that is the standing wave that forms between those quarks. Unlike in neutrons where that standing wave form between the neutron shell and the up quark the standing wave that puts those quarks pushes each other away from those quarks. Unlike in baryons, in mesons, the standing wave has no space where it can go. Energy can travel to the meson's shell and destroy that quantum field. Or it can push the quarks away from each other with its full power. 

"A hadron is a composite subatomic particle. Every hadron must fall into one of the two fundamental classes of particle, bosons and fermions." (Wikipedia, Hadrons)

"In particle physics, a meson  is a type of hadronic subatomic particle composed of an equal number of quarks and antiquarks, usually one of each, bound together by the strong interaction. Because mesons are composed of quark subparticles, they have a meaningful physical size, a diameter of roughly one femtometre (10−15 m),which is about 0.6 times the size of a proton or neutron. All mesons are unstable, with the longest-lived lasting for only a few tenths of a nanosecond. Heavier mesons decay to lighter mesons and ultimately to stable electrons, neutrinos and photons." (Wikipedia, Meson)

"Outside the nucleus, mesons appear in nature only as short-lived products of very high-energy collisions between particles made of quarks, such as cosmic rays (high-energy protons and neutrons) and baryonic matter. Mesons are routinely produced artificially in cyclotrons or other particle accelerators in the collisions of protons, antiprotons, or other particles." (Wikipedia, Meson)

Toponum: the meson with top quark and its antiquark 

"Of all the particles in the Standard Model, the heaviest one is also the shortest-lived: the top quark (and antiquark), which lives for just half a yoctosecond. Based on the range of the strong force and the top quark’s short lifetime, it was predicted that the top quark could never bind together with other quarks, simply decaying too quickly to do so. But in rare cases, quark-antiquark pairs involving top and antitop quanta can indeed form a bound state before decaying: toponium. Both CMS and ATLAS have now validated toponium’s existence at the LHC." (BigThink, The top quark isn’t a loner after all: “toponium” is real!)

Toponium is one of the quarkoniums. "In particle physics, quarkonium (from quark and -onium, pl. quarkonia) is a flavorless meson whose constituents are a heavy quark and its own antiquark, making it both a neutral particle and its own antiparticle. The name "quarkonium" is analogous to positronium, the bound state of electron and anti-electron. The particles are short-lived due to matter-antimatter annihilation." Wikipedia, Quarkonium)

The existence of the toponium is almost certain. That thing is a new type of particle. It’s the composite particle involving the top quark and its antiquark. The existence of toponium remains only for a very short time. The top quark must not touch its antiquark or the toponium turns into energy. That very high-energy composite particle can open a view into the top quark behavior. 

And maybe that thing can tell researchers about the possibility that somewhere at the beginning of the universe were composite particles that involved some other than up and down quarks. Those particles' existence is not possible in our universe. The top quark’s large mass makes those particles very unstable under normal conditions. In the same way if the top quark touches it anti quark that causes annihilation. 

The existence of the top and bottom quark-based baryons is not possible in the modern universe. But maybe in a very young universe conditions like energy level were high enough that the highest energy quarks could form material. But when the temperature in the universe decreased, the outside energy could not push those high-energy particles against each other. When the energy level in the universe decreased, those composite particles decayed. And the quarks jumped away from that structure. 

The toponium is not the bound state of charmium or bottonium. The top quark has no time to hadronize or make the bounds with charm or bottom quarks. An interesting thing is that toponium will involve particles and its antiparticle pair, the antitop quark. When toponium annihilates that reaction releases energy and those quarks turn into wave movement. If toponium is someday confirmed, that will open new paths to particle physics. 

https://bigthink.com/starts-with-a-bang/top-quark-loner-toponium/

https://home.cern/news/news/physics/cms-finds-unexpected-excess-top-quarks

https://indico.cern.ch/event/1444046/contributions/6216409/attachments/2966217/5218739/intro-toponium-maltoni.pdf

https://en.wikipedia.org/wiki/Baryon

https://en.wikipedia.org/wiki/Hadron

https://en.wikipedia.org/wiki/Meson

https://en.wikipedia.org/wiki/Quarkonium