Derivation of a novel formula for α-decay half-life

Based on the basic principle of quantal decay of particle, we derive a formula of logarithm of decay half-life of an alpha particle emitting from a radioactive nucleus. The process of decay is understood as the transition of the particle from an isolated quasi-bound state to a scattering state. In this picture, the decay width is a resonance width in the system consisting of an α-cluster and the residual nucleus