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Published equation contexts

−aCZ(Z−1)/A1/3-a_C Z(Z-1)/A^{1/3}

Why this formula appears here

Read as a fitness landscape, each term is a distinct cost or bonus of viability rather than an abstract fitting parameter. The volume term, aVa_V A , is the baseline: every nucleon in the interior feels attraction from its immediate neighbors, so binding energy grows roughly in proportion to the number of nucleons, the way a population’s raw fitness might scale with sheer numbers before any structural penalty is applied. The surface term, -aSa_S A2/3A^{2/3} , subtracts a cost proportional to surface area, because nucleons at the boundary have fewer neighbors to bind to — a tax on being exposed at the edge of the configuration, heaviest for small A where the surface-to-volume ratio is largest. The…

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aCa_C

Symbol a_C

aCa_C is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

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A1/3A^{1/3}

Symbol A^1/3

A1A^1/3 is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.

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Published contexts (1)

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−aCZ(Z−1)/A1/3-a_C Z(Z-1)/A^{1/3}

Equation 13 · Evolutionary Nuclear Physics

The Valley of Stability Is a Fitness Landscape

This mathematical expression combines the displayed quantities; its precise role follows from the surrounding article text.

Read as a fitness landscape, each term is a distinct cost or bonus of viability rather than an abstract fitting parameter. The volume term, aVa_V A , is the baseline: every nucleon in the interior feels attraction from its immediate neighbors, so binding energy grows roughly in proportion to the number of nucleons, the way a population’s raw fitness might scale with sheer numbers before any structural penalty is applied. The surface term, -aSa_S A2/3A^{2/3} , subtracts a cost proportional to surface area, because nucleons at the boundary have fewer neighbors to bind to — a tax on being exposed at the edge of the configuration, heaviest for small A where the surface-to-volume ratio is largest. The…

Meanings in this article

  • ZZ: the mass number.
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