Figure 1

Summary of collective and seniority-dominated schemes. (a) and (b) Experimental yrast $B\left(E2\right)$ values for $62⩽Z⩽74$. A few nuclei with known low-lying intruder states are omitted for clarity. (c) Illustration of seniority quantum numbers. (d) Calculated $B\left(E2\right)$ values [from Eqs. (1, 2) ] for $J\to J-2$ transitions for seniority conserving and nonconserving transitions as a function of fractional filling. (e) Schematic illustration of $B\left(E2;J\to J-2;J\ne 2\right)$ plotted against $B\left(E2;2^{+}\to 0^{+}\right)$ for seniority and collectivity-dominated transitions.Reuse & Permissions

Figure 2

(a) Experimental $B\left(E2\right)$ values (solid circles) for semimagic $\left(N=126\right)$ isotones of Po, Rn, and Ra [14, 15, 16]. Open circles denote calculated values from Eqs. (1, 2), normalized for Po. (b) Experimental $B\left(E2;8^{+}\to 6^{+}\right)$ values for the Po, Rn, Ra isotones for $N=118–128$ [8, 12, 13, 14, 15, 16, 17, 18, 19, 20]. Arrows denote lower limits.Reuse & Permissions

Figure 3

Partial nuclear chart for even-even nuclei, showing stable nuclei in white, those proposed to exhibit good seniority in black (known data) and gray (assuming normal magic numbers). Insets show $B\left(E2\right)$ data in Weisskopf unit (W.u.) for four regions (solid circles, [9, 11, 14, 15, 16, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36]) compared to seniority calculations (open circles), normalized to the leftmost point in each case. If magic numbers differ far from stability, new seniority regimes may appear.Reuse & Permissions