Are there Hadrons with more than three quarks?

In summary, the conversation touched on the different types of subatomic particles, such as mesons and baryons, and the possibility of hadrons containing more than three quarks. The potential discovery of penta-quark hadrons was also mentioned, along with the concept of exotic states and the difficulty in verifying them. The existence of hexaquarks and tetraquarks was also discussed, with the latter being confirmed through its decay products.
  • #1
KBon
As far as I know there are Mesons (quark-Antiquark pair) and Baryons (three quarks). But are there Hadrons which contain more than 3 Quarks?
 
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  • #2
Hi and welcome to PF!
There has been a lot of hype lately that the LHC discovered penta-quark hadrons but I don't know much about it, other than there are 5 quarks involved.
 
  • #3
See https://en.wikipedia.org/wiki/Pentaquark
It is probably a baryon-meson molecule. Of course there are also dodeca-quarks = alpha-particles, stable bound states of 12 quarks, or of two protons and two neutrons, and heavier nuclei.
 
  • #4
Aight, I'll surely look it up. Thank you very much :) @jerromyjon @A. Neumeier
 
  • #5
In meson-baryon scattering, ## q\bar{q} + qqq##, one typically sees resonances (short-lived particles) only for ##qqq## systems, where one ##q## annihilates with the ##\bar{q}##. States such as ##qqqq\bar{q}## where there is no ##q## able to annihilate the ##\bar{q}## are called exotic and no such resonances have been verified. This is most easily seen in ##K^+p## scattering.
 
  • #6
The only well-known hexaquark is orthodeuteron, and it behaves strongly as a bound system of two separate nucleons.
Paradeuteron, diproton and dineutron are confirmed to be unbound.
Are there any other hexaquarks that are bound?
With 5 quarks participating in baryons, there are a lot of combinations to check...
 
  • #8
How is a tetraquark verified to be that?
 
  • #9
Z(4430) decays to ## J/\psi \,\pi^\pm##, and based on its mass it cannot have a b quark, so it has to have ##c \bar c## in it. It also has a charge, so it needs at least two more quarks.
 

FAQ: Are there Hadrons with more than three quarks?

1. What are hadrons?

Hadrons are subatomic particles made up of quarks that are held together by the strong nuclear force. They are classified into two categories: baryons, which contain three quarks, and mesons, which contain one quark and one antiquark.

2. Are there hadrons with more than three quarks?

Yes, there are hadrons with more than three quarks, known as exotic hadrons. These include tetraquarks, which have two quarks and two antiquarks, and pentaquarks, which have four quarks and one antiquark.

3. How do we know about these exotic hadrons?

Exotic hadrons have been discovered through experiments at particle accelerators, such as the Large Hadron Collider. These experiments involve colliding particles at high energies, allowing researchers to study the subatomic particles produced in these collisions.

4. What is the significance of discovering exotic hadrons?

The discovery of exotic hadrons helps us to better understand the fundamental building blocks of matter and the strong nuclear force that holds them together. It also provides insights into the structure of the Universe and the conditions that existed shortly after the Big Bang.

5. Could there be hadrons with even more quarks?

It is possible that there could be hadrons with more than five quarks, but they have not yet been observed. Theoretically, there is no known limit to the number of quarks that can be bound together to form a hadron, but the complexity of these particles makes them difficult to detect and study.

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