next up previous
Next: Natural origins of strange Up: Small (Atomic Size) Strangelets Previous: A model for A

The predictions

Even though this model is fairly simplistic and cannot make detailed predictions, it does yield several fascinating qualitative features of small strangelets. It begins to fill the bag with the massless nonstrange quarks. Soon tex2html_wrap_inline438 becomes large enough that it becomes energetically favorable to begin adding strange quarks. At some point it again becomes favorable to add nonstrange quarks. As the radius of the bag increases, the strange and nonstrange energy levels will change at different rates. As a result, the levels do not fill with a simple cycling through the quark flavors. The variation of energy levels with respect to each other yields level crossings at some values of A, where the strange quarks will ``unload'' into the nonstrange levels. One such crossing occurs at A = 30.

There are also points in the filling where tex2html_wrap_inline444 drops rapidly. In this case, the decrease in energy from emitting a baryon in insufficient to offset the energy need to climb out of the dip. The increased stability at these points is reminiscent of a shell closure in nuclear or atomic physics. In fact, the first few dips coincide with the filling of a strange s tex2html_wrap_inline446 , non-strange p tex2html_wrap_inline448 , p tex2html_wrap_inline446 , and strange p tex2html_wrap_inline448 shells. As in nuclear structure, the specific locations and order of the shell closures will depend on the details of the potential (the bag in this case).

Bulk strange matter is predicted to have tex2html_wrap_inline454 , as equal numbers of u, d, and s quarks give a charge near zero. In small strangelets the shell structures will determine the allowed charges for stable strangelets. In the limit of massless u and d quarks, there is an isospin symmetry allowing 2 equally stable species for most A.

The model also validates the expectation that the spatial density of strange quarks will be peaked near the center of the strangelet.


next up previous
Next: Natural origins of strange Up: Small (Atomic Size) Strangelets Previous: A model for A

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