Ground state energy of nucleus

maxverywell
Messages
197
Reaction score
2
How do we compute the energy of the ground state using nuclear shell model?
 
Physics news on Phys.org
Typically this is done using the Strutinsky shell correction method.
 
Your questions is a bit ambiguous.
1) Excitations energy: The ground state has (per definition) energy 0, the excited states have a positive excitations energy
2) Theoreticians calculate it from first principles, and they are more or less successful doing so. If your question is about theoretical calculations, you would have to dig into a good number of books.
3) Or do you want to know about the "Binding Energy"? if this is the case: here comes the explanation:
a nucleus consists of x protons and y neutrons. The mass of the nucleus is then:
M(nucleus) = x times M(proton) + y times M(neutron) - Q
where M(xxx) is the mass of the particle (usually expressed in MeV), and Q is the "Binding Energy". For example, the He4-nucleus consists of 2 protons and 2 neutrons,and has a Binding energy of ~28 MeV. Protons have a mass of 938.27 MeV and neutrons have a mass of 939.56 MeV. The mass of 4He is then: 2 * (938.27 + 939.56) - 28 = ~3727.6 MeV

(note: "MeV" is an energy unit. if one speaks about "mass" one should more correctly write "MeV/c^2")
 
thsb said:
1) Excitations energy: The ground state has (per definition) energy 0, the excited states have a positive excitations energy
But this is obviously not what the OP was asking.

thsb said:
2) Theoreticians calculate it from first principles, and they are more or less successful doing so. If your question is about theoretical calculations, you would have to dig into a good number of books.
No, the Strutinsky shell correction is actually quite simple.

thsb said:
3) Or do you want to know about the "Binding Energy"? if this is the case: here comes the explanation:
a nucleus consists of x protons and y neutrons. The mass of the nucleus is then:
M(nucleus) = x times M(proton) + y times M(neutron) - Q
where M(xxx) is the mass of the particle (usually expressed in MeV), and Q is the "Binding Energy". For example, the He4-nucleus consists of 2 protons and 2 neutrons,and has a Binding energy of ~28 MeV. Protons have a mass of 938.27 MeV and neutrons have a mass of 939.56 MeV. The mass of 4He is then: 2 * (938.27 + 939.56) - 28 = ~3727.6 MeV

(note: "MeV" is an energy unit. if one speaks about "mass" one should more correctly write "MeV/c^2")
The OP asked about how to calculate it using the shell model, not how to extract it from experimental data.
 
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}...

Similar threads

Back
Top