multiplicities. Here, ε$_{0}$ is the excitation energy of the decaying nucleus, B$_{0}$ its binding energy and E$_{c}$$_{0}$ is a term associated with the Wigner-Seitz correction to the Coulomb energy of the system. V$_{n}$ is the volume in which the momentum states are normalized and is usually defined as [8] where V$_{0}$ is the ground state volume of the decaying nucleus and the expansion factor χ is usually taken to be χ = 1 . For the fragments, B$_{j}$ is the binding energy of fragment j and g$_{j}$ is its spin multiplicity, while the E$_{cj}$ represent the remaining Wigner-Seitz corrections to the Coulomb energy, taken to be Conservation of nucleon number and charge requires that where Z$_{j}$ and A$_{j}$ are the charge and mass number, respectively, of fragment j . The FBM assumes that the fragments are emitted in their ground states or in (almost) particle-stable excited states. As the total excitation energy is increased, other particle-unstable excited states that are long-lived in comparison to the initial decaying nucleus could also be included and can make significant contributions to the phase space integral[27]. These can be incorporated compactly using the densities of excited states of the fragments. Such an extension of the Fermi breakup integral takes the form where ε$_{j}$ is the excitation energy of fragment j , ω$_{j}$ ( ε$_{j}$ ) its density of states and B$_{j}$ is now its ground-state binding energy. Note that this expression does not contain the fragment spin multiplicities, g$_{j}$ , which are now assumed to be incorporated in the density of states. For a particle with no excited states, we have ω$_{j}$ ( ε$_{j}$ ) = g$_{j}$δ ( ε$_{j}$ ) . 4 A$_{0}$ = n ∑ j =1 A$_{j}$ = k ∑ l =1 N$_{l}$ A$_{l}$ and Z$_{0}$ = n ∑ j =1 Z$_{j}$ = k ∑ l =1 N$_{l}$ Z$_{l}$ , (8) E$_{cj}$ = C$_{Coul}$ (1 + χ ) 1 / 3 Z 2 j A 1 / 3 j . (7) ω$_{n}$ = k ∏ l =1 1 N$_{l}$ ! ( V$_{n}$ (2 π ℏ ) 3 ) n − $^{1}$∫ n ∏ j =1 d $^{3}$p$_{j}$ δ ( n ∑ j =1 ⃗ p$_{j}$ ) (9) × ∫ n ∏ j =1 ( ω$_{j}$ ( ε$_{j}$ ) dε$_{j}$ ) δ ( ε$_{0}$ − B$_{0}$ − E$_{c}$$_{0}$ − n ∑ j =1 ( p 2 j 2 m$_{j}$ + ε$_{j}$ − B$_{j}$ − E$_{cj}$ ) , V$_{n}$ = (1 + χ ) V$_{0}$ , (6)