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New exotic matter particle, a tetraquark, discovered at CERN

phys.org

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Re: New exotic matter particle, a tetraquark, discovered at CERN

#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.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#4
The article points to an ongoing conference as the source, unfortunately (despite having no registration fee) the live-stream is password protected for non-participants :(

https://www.eps-hep2021.eu/live_stream/

Edit: It seems the talks may be released, in the end

>We would like to record your presentation at the EPS-HEP2021 conference and make it publicly available via the INDICO page and the DESY media streaming server until one week after the end of the conference.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#5
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 more likely (I'm not a physicist) is to watch the decay of the particle and trace it back from there.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#8
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 around until it decayed, and then you'd often be able to see some charged remnants.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#9

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 calculation techniques.

Re: New exotic matter particle, a tetraquark, discovered at CERN

#10
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.

I don't think that's a unique property to tetraquarks. Neutrons or neutrinos also are not electrically charged. I'm not sure what you mean by untraceable, but neutrinos rarely interact with other particles and many, many of them pass through you every second without you even noticing.
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