Posted on 07/09/2020 2:47:36 PM PDT by BenLurkin
All tetraquarks and pentaquarks that have been discovered so far contain two charm quarks, which are relatively heavy, and two or three light quarks – up, down or strange. This particular configuration is indeed the easiest to discover in experiments.
But the latest tetraquark discovered by LHCb, which has been dubbed X(6900), is composed of four charm quarks. Produced in high-energy proton collisions at the Large Hadron Collider, the new tetraquark was observed via its decay into pairs of well-known particles called J/psi mesons, each made of a charm quark and a charm antiquark. This makes it particularly interesting as it is not only composed entirely of heavy quarks, but also four quarks of the same kind – making it a unique specimen to test our understanding on how quarks bind together.
For now, there are two different models that could explain how quarks bind together: it could be that they are strongly bound, creating what we refer to as a compact tetraquark. Or it could be that the quarks are arranged to form two mesons, which are stuck together loosely in a “molecule”.
Ordinary molecules are made from atoms bound together by the electromagnetic force, which acts between positively charged nuclei and negatively charged electrons. But the quarks in a meson or baryon are connected via a different force, the “strong force”.
The new particle appears to be most consistent with being a compact tetraquark rather than a two-meson molecule, which was the best explanation for previous discoveries. This makes it unusual, as it will allow physicists to study this new binding mechanism in detail. It also implies the existence of other heavy compact tetraquarks.
(Excerpt) Read more at theconversation.com ...
Good grief
“All tetraquarks and pentaquarks that have been discovered so far contain two charm quarks, which are relatively heavy, and two or three light quarks – up, down or strange.”
Wasn’t this revealed last year on The Big Bang Theory?
The strong nuclear force is what bonds protons and neutrons together...if it is true that this also holds these newly discovered particles in place it will call for a reworking of the Standard Model
That’s where I left my extra charm.
Physics was easier when I was in high school before they discovered all of this. (It was even easier because our textbooks were about 25 years old. At least they were printed after the discovery of gravity.)
It's not only lucky, it's magically delicious.
What is the lifespan of these particles? Remember everyone should be concerned about HLM - Half-Lives Matter.
Wow, img align="left" also makes my ping page go cray-cray. And good catch, those do look like vintage Cray supercomputers.
tetraquarks and pentaquarks
I need to brush up on my quarks.
When they reached triquarks, I stopped tryin'.
More particles....can’t wait till we get to the particle which only bounces out when all the energy in the galaxy is needed to force it out of hiding.
But the Cernettes are fabulous. Disbanded in 2012, but got back together for a new classic The Lockdown Song May 2020. It's hillarious.
The project was an utter disaster and should have been terminated. Go read Tunnel Visions: The Rise and Fall of the Superconducting Super Collider
I can vouch for the fact that it was really as badly run as the book describes.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.