Continuum two-body reactions

In the rest of this note, for reasons of clarity we shall use the notation that m_targ denotes the mass of the target and that W_targ is its excitation level. Similarly, we say that m_yi and E_yi are the mass and energy of the incident particle and m_yo and E_yo the mass and energy of the secondary particle. Furthermore, m_res, E_res, and W_res denote, respectively, the mass, kinetic energy, and excitation level of the residual.

For continuum two-body reactions the endep code works with energy-distribution data ( $\tt I\_number$ = 4) in the laboratory frame. That is, for a set of incident energies E_yi, we are given probability densities P(E_yi, E_yo) that the secondary particle has energy E_yo. The total average energy of the secondary particle corresponding to an incident particle at energy E_yi is therefore computed by evaluating the integral

$$\langle \rangle \int$$ (16)

Here, the limits of integration are the minimum and maximum possible energies for the secondary particle.

If energy distributions are given for the gammas and if this residual decays only by gamma emission, then the average gamma energy $\langle$E_$\gamma$$\rangle$ is also calculated by using (16). In that case, the average energy of the residual $\langle$E_res$\rangle$ is obained from energy conservation (2),

$$\langle \rangle \langle \rangle \langle \gamma \rangle$$ (17)

Also, if the residual nucleus is an alpha or lighter, it is assumed that there is no gamma emission, and the average energy of the residual is taken to be

$$\langle$$E_res$$\rangle$$ = E₁ + Q - $$\langle$$E_yo$$\rangle$$.