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The results

The model predicts that the charge of a strangelet will be proportional to tex2html_wrap_inline352 . This is in contrast to nuclear matter, where tex2html_wrap_inline354 . The coulomb energy goes as tex2html_wrap_inline356 at constant density. What is important for stability is that the total energy per baryon be less than the mass of a free nucleon. For nuclear matter, the coulomb energy per baryon goes as

displaymath358

As this increases with A, there is a point where a nuclear matter becomes unstable, at around A = 250. In strange matter the energy per baryon is

displaymath364

and strange matter becomes increasingly stable with A. This behavior is one of the primary concepts in understanding the phenomenology of strangelets.

Since tex2html_wrap_inline368 , the coulomb energy will drive tex2html_wrap_inline370 for large A. For tex2html_wrap_inline372 , this is consistent with a minimization of the `symmetry energy,' since equal numbers of each flavor result no net charge. For tex2html_wrap_inline374 , the model predicts an increase in charge. A massive strange quark shifts the symmetry energy minimum toward non-zero Z/A, so that with increasing A the coulomb energy going to zero will force an increase in the symmetry energy. In the absence of surface effects, this would lead to a destabilization of the strangelet. However, the charge to baryon ratio Z/A is so small that surface effects can easily compensate for the coulomb energy. This prediction of tex2html_wrap_inline370 for large A is also inconsistent with the bulk limit. This is because electrons are not present in strangelets; if they are included, consistency is restored.

Electrons would be expected to surround a strangelet in `atomic' orbitals. For a strangelet of charge 100, the Bohr radius of the inner shell tex2html_wrap_inline384 will be much larger than the size of the strangelet. It would resemble a superheavy atom, with tex2html_wrap_inline386 . A strangelet of tex2html_wrap_inline388 would have a charge of about 1000; the simple minded Bohr radius of its innermost electron would be about 53 fm, compared to a strangelet radius of about 200 fm. Although this is much to simple a picture to determine the percentage of electrons near the core of the strangelet, it is clear that the transition to bulk strange matter is near.


next up previous
Next: Small (Atomic Size) Strangelets Up: Strangelets (A ) and Previous: A model

Joshua Holden
Sun May 17 15:37:00 EDT 1998