Quasiclassical description of bremsstrahlung accompanying α decay including quadrupole radiation

We present a quasiclassical theory of α decay accompanied by bremsstrahlung with a special emphasis on the case of 210Po, with the aim of finding a unified description that incorporates both the radiation during the tunneling through the Coulomb wall and the finite energy Eγ of the radiated photon up to Eγ∼Qα/√(η), where Qα is the α-decay Q-value and η is the Sommerfeld parameter. The corrections with respect to previous quasiclassical investigations are found to be substantial, and excellent agreement with a full quantum mechanical treatment is achieved. Furthermore, we find that a dipole-quadrupole interference significantly changes the α-γ angular correlation. We obtain good agreement between our theoretical predictions and experimental results