Background of existence of the two low-lying adjacent 4(+) narrow resonances in O-16 nucleus and other 4-boson systems

Based on an analysis of the inherent nodal structures of wavefunctions of 4 -boson systems, we found that the internal energy of the 4(1)(+) state shou ld be lower because its structure can be optimized without suffering a stro ng constraint arising from symmetry (while other 1 less than or equal toL l ess than or equal to3 states suffer from this kind of constraint). Furtherm ore, two superior structures favourable in binding are found to be allowed to be possessed by 4(+) states. These findings would lead to the appearance of two adjacent 4(+) states, as a common feature, in the low-lying spectra of 4-boson systems.