  In this work we study the radiative decays of heavy-light quarkonia through
M1 and E1 transitions, that involve quark-triangle diagrams with two hadron
vertices, and are difficult to evaluate in BSE-CIA. We have expressed the
transition amplitude, $M_{fi}$ as a linear superposition of terms involving all
possible combinations of $++$, and $--$ components of Salpeter wave functions
of final and initial hadron, with coefficients being related to results of pole
integrals over complex $\sigma$- plane. We evaluate the decay widths for $M1$
transitions ($^3S_1 \rightarrow ^1S_0 +\gamma$), and $E1$ transitions ($^3S_1
\rightarrow ^1P_0 +\gamma$ and $^1P_0 \rightarrow ^3S_1 +\gamma$). We have used
algebraic forms of Salpeter wave functions obtained through analytic solutions
of mass spectral equations for ground and excited states of $0^{++},1^{--}$,
and $0^{-+}$ heavy-light quarkonia in approximate harmonic oscillator basis, to
calculate their decay widths. The input parameters used by us were obtained by
fitting to their mass spectra. We have compared our results with experimental
data and other models, and found reasonable agreements.
