Is the Nucleus Just a Clump of Quarks or Are Protons and Neutrons Grouped?

  • Thread starter Thread starter Jonnyb42
  • Start date Start date
  • Tags Tags
    Grouping
Jonnyb42
Messages
185
Reaction score
0
Nucleas Grouping??

Why do we say a nucleus is composed of protons and neutrons when those protons and neutrons are themselves composed of quarks?

Is there really grouping to these protons and neutrons or do we just say it is composed of protons and neutrons for convenience (and that it is really just a quark clump)?

I ask only specific to a nucleus because I know that during decays and such groups of 3 quarks (uud) will be called a proton, but is it so in a nucleus?

If there is grouping of protons and neutrons within the nucleus, what prevents them from meshing all together to just be a quark cluster?

thanks,
Jonny
 
Physics news on Phys.org


Yes, there is grouping into protons and neutrons in the nucleus. What you call a quark cluster is called quark gluon plasma and only observed in high energy collisions of atomic nuclei for very short times. You may compare it e.g. to a solid of a noble gas. There, the atoms also don't fuse into a structureless lump but keep their identity.
 
Toponium is a hadron which is the bound state of a valance top quark and a valance antitop quark. Oversimplified presentations often state that top quarks don't form hadrons, because they decay to bottom quarks extremely rapidly after they are created, leaving no time to form a hadron. And, the vast majority of the time, this is true. But, the lifetime of a top quark is only an average lifetime. Sometimes it decays faster and sometimes it decays slower. In the highly improbable case that...
I'm following this paper by Kitaev on SL(2,R) representations and I'm having a problem in the normalization of the continuous eigenfunctions (eqs. (67)-(70)), which satisfy \langle f_s | f_{s'} \rangle = \int_{0}^{1} \frac{2}{(1-u)^2} f_s(u)^* f_{s'}(u) \, du. \tag{67} The singular contribution of the integral arises at the endpoint u=1 of the integral, and in the limit u \to 1, the function f_s(u) takes on the form f_s(u) \approx a_s (1-u)^{1/2 + i s} + a_s^* (1-u)^{1/2 - i s}. \tag{70}...
Back
Top