New exotic matter particle, a tetraquark, discovered at CERN

Post by akomtu » Fri, Jul 30, 2021, 5:24 PM UTC

whatshisface wrote: post #8

akomtu wrote: post #2

The article (light on details, as usual) mentions that a slightly different configuration of a tetraquark would be very stable (again, not sure if that means nanoseconds or hours). If such stable multiquarks exist, without an electric charge they would be effectively untraceable, right? The only way to see such a particle would be to hit it precisely with an even smaller particle and get it to bounce back.

> The only way to see such a particle would be to hit it precisely with an even smaller particle and get it to bounce back. Bounce back from what force? Whatever forces would make it interact with a single particle would make it interact with a detector, which is itself made out of particles. They say the extra-stable tetraquark would only be susceptible to decay via the weak force, which means you'd have to wait aro…

Post by whatshisface » Fri, Jul 30, 2021, 5:30 PM UTC

akomtu wrote: post #12

whatshisface wrote: post #8

Earlier quoted context omitted.

> The only way to see such a particle would be to hit it precisely with an even smaller particle and get it to bounce back. Bounce back from what force? Whatever forces would make it interact with a single particle would make it interact with a detector, which is itself made out of particles. They say the extra-stable tetraquark would only be susceptible to decay via the weak force, which means you'd have to wait aro…

Can such tetraquarks form semi stable macroscopic structures like atoms? For example, if they aren't completely neutral, a group of them would be able to maybe attract an electron and become a quasiatom of some sort.

Post by lcfcjs » Fri, Jul 30, 2021, 5:34 PM UTC

whatshisface wrote: post #9

oldspleen wrote: post #7

someone please ELI5 and how this discovery is important for furthering our understanding of quantum numbers

The laws governing the strong force are somewhat well-known at this point, but calculations involving them are difficult and in many cases beyond our reach. Furthermore the fundamental constants are not known to a very high precision. Both of these problems can be addressed by collecting experimental data about how these particles behave in real life, both to pin down the constants, and to accept or reject calculatio…

Post by Gravityloss » Fri, Jul 30, 2021, 5:36 PM UTC

whatshisface wrote: post #15

Gravityloss wrote: post #13

Earlier quoted context omitted.

So not usable as spaceship fuel

If you're allowed to use something produced in an accelerator as your fuel you can't beat antimatter, which is as stable as normal matter until Kirk orders warp one.

Post by phkahler » Fri, Jul 30, 2021, 5:36 PM UTC

whatshisface wrote: post #11

danslo wrote: post #3

>Such proximity in mass makes the decay "difficult," resulting in a longer lifetime of the particle, and indeed Tcc+, is the longest-lived exotic hadron found to date. So... how long does it live?

The resonance width is inversely proportional to the lifetime, and if the resonance width is about 400keV, the particle would live for about 10^-21 seconds. For comparison, neutrons decay via the weak force in about 800 seconds, and delta baryons, a randomly chosen strong force decay, live for 10^-24 seconds. That makes this tetraquark long-lived for a strong decay, but that's way, way faster than a weak decay. https…