Collectivity, Structured Yrast Lines, and Correlated Energies in Random Bosonic Systems

Toy systems of N particles on a single lrvrl with spin  j = 3, 4 . . . 7 , and on 2 levels with spins (j₁, j₂) with j₁ + j₂ ≤ 6 were studied. The yrast lines were surprisingly rich in scructure. They exhibit collectivity and were often consistant with a deformed rotating core. The moment of inertia of these cores had discrete jumps, suggestive of a realignment of the constituents. Strong signatures of order and collectivity were the norm. These included the usual energy ratios and quadropole transition strengths for vibrational and rotational bands. The quadropole moments of the lowest states mimiced results of real nuclei. There were pronounced correlations in energy ratios, sharp peaks in the Alaga ratios and fractional collectivity across all the 1-level systems, as well as signatures of triaxiality.