The experimental values of both branching ratios and hindrance factors for the alpha decay of even-even trans-lead nuclei, corresponding to the 2 + 1 , 4 + 1 , and 6 + 1 excited states in the daughter nucleus, are examined within the valence correlation scheme. Existing calculations do not reproduce certain conspicuous features of these data in the deformed nuclei region, thus leaving open the question of what details of nuclear structure in this region are responsible for these effects.Although it is one of the oldest observed nuclear structure phenomena, alpha decay remains a very important experimental tool for the investigation of unstable nuclei, especially the superheavy ones. The fine structure of the alpha decay was experimentally observed by Salomon Rosenblum in 1929 [1], and, soon after that, explained by Gamow [2] as due to the population of the ground and excited states in the daughter nucleus.The population of the excited states in the residual nucleus is usually much weaker than that of the ground state, mainly due to the different Q values, reflecting the strong energy dependence of the penetrability of the alpha particle through the nuclear and Coulomb potential barrier. On the other hand, the population intensity of the excited states also contains important information on their structure. However, the theoretical calculation of the absolute values of the alpha-decay rates is a problem that is not fully solved yet. The best studied alphadecay processes are those implying the unhindered transitions (with L = 0), that have mostly been measured for the ground state to ground state transition of even-even nuclei, whereas the population of the excited states in the daughter nuclei (the fine structure of α decay), especially for nonzero spin states, has been much less studied. In this work we show that the experimental fine structure data for the yrast 2 + , 4 + , and 6 + states in even-even trans-lead daughter nuclei are not fully understood by the current theoretical models of alpha decay, implying that certain details of the structure of these states are neglected, or even not understood. To this end, we review the systematics of the experimental data [3-5] on the α-decay fine structure measured for the even-even trans-lead nuclei.The quantities experimentally determined in alpha decay are the Q values (related to the excitation energies of the daughter nucleus states), the branching ratios B r,i (for excited states denoted by i), and the half-life T 1/2 of the alpha-decaying state in the parent nucleus (in our case, the 0 + ground state). For each state i one defines a partial half-life T 1/2,i = T 1/2 /B r,i and a partial width i =h ln 2/T 1/2,i . One usually factorizes the widths as i = δ 2 i P i where δ 2 is called reduced width [6] and mainly contains the nuclear structure information, while * bucurescu@tandem.nipne.ro † zamfir@tandem.nipne.ro P is the penetrability of the alpha particle through the barrier. For comparison with theory one also defines the hindrance factors (HFs) asThus, for the...