Ground state energy of nucleus

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Discussion Overview

The discussion focuses on the computation of the ground state energy of a nucleus using the nuclear shell model. Participants explore various methods and concepts related to this topic, including theoretical calculations and the binding energy of nuclei.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant inquires about the method for computing the ground state energy using the nuclear shell model.
  • Another participant suggests the Strutinsky shell correction method as a typical approach for this calculation.
  • A third participant clarifies that the ground state energy is defined as zero, while excited states have positive excitation energies, but questions whether this aligns with the original inquiry.
  • This participant also mentions that theoretical calculations can be complex and may require extensive literature review.
  • There is a discussion about binding energy, with a participant explaining the mass-energy relationship in terms of protons, neutrons, and binding energy, using the Helium-4 nucleus as an example.
  • Another participant challenges the previous points by asserting that the Strutinsky shell correction is a straightforward method and emphasizes that the original question was about the shell model, not experimental data extraction.

Areas of Agreement / Disagreement

Participants express differing views on the clarity of the original question and the appropriateness of the proposed methods. There is no consensus on the best approach to compute the ground state energy, and multiple perspectives on the topic remain unresolved.

Contextual Notes

Some assumptions about the definitions of ground state and excited state energies are present, and there are unresolved aspects regarding the complexity of theoretical calculations and the relationship between binding energy and mass. The discussion does not reach a definitive conclusion on the methods discussed.

maxverywell
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How do we compute the energy of the ground state using nuclear shell model?
 
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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.
 

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