B(E2) Help
Explanation of Tables
| Column Name | Description |
|---|---|
| Nuclide | The even Z, even N nuclide studied |
| Transition Energy | Energy of the first excited 2⁺ state, in keV |
| Transition Rate Ratio |
B(↑) = (2J + 1)B(↓) / (2J₀ + 1) where J₀ and J are spins of the lower and upper levels, respectively. |
| B(E2; 0⁺ → 2⁺) | Reduced electric quadrupole transition rate for the ground state to 2⁺ state transition in units of e²b². |
| W.u. |
Weisskopf units. These are based on single-particle estimates for the λ-th multipole reduced electric transition probability and originally were used for transitions from higher to lower states: Bw(Eλ) = (1/4π)(3 / (λ + 3))2(1.2)2λA2λ/3 e2fm2λ Weisskopf (single-particle) B(E2) values for 0⁺ → 2⁺ transitions are given by: Bw(E2↓) = 0.297 × A4/3 e2fm4 |
| τ |
Mean lifetime of the state in picoseconds (ps) τ = 40.81 × 1013E-5[B(E2↑) / e2b2]-1(1 + α)-1 |
| β |
Deformation parameter β = (4π / 3ZR02)[B(E2↑) / e2]1/2 where R02 = (1.2 × 10-13 A1/3 cm)2 = 0.0144A2/3b |
| Q₀ |
Intrinsic quadrupole moment in b Q0 = [16πB(E2↑) / 5e2]1/2 |
| Reference | Nuclear Science References (NSR) database abstract |
| Global Best Fit | Global best fit for B(E2)↑ as given by S. Raman, C.W. Nestor and P. Tikkanen. |
| Modified Grodzins rule |
B(E2↑) = (2.57 ± 0.45)E-1Z2A-2/3 β = (466 ± 41)E-1/2A-1 |