The double beta decay of ¹³⁶Xe to excited states of ¹³⁶Ba (DBD-ES) has not yet been discovered experimentally. The experimental signature of such decays, one or two gamma rays following the beta signals, can be identified more effectively in a gaseous detector with the help of topological signatures. We have investigated key parameters of particle trajectories of DBD-ES with Monte Carlo simulation data of the proposed PandaX-III detector as an example. The background rates can be reduced by about one order of magnitude while keeping more than half of signals with topological analysis. The estimated half-life sensitivity of DBD-ES can be improved by 1.8 times to 4.1×10²³ year (90% C.L.). Similarly, the half-life sensitivity of neutrinoless double beta decay of ¹³⁶Xe to excited states of ¹³⁶Ba can be improved by a factor of 4.8 with topological signatures.

尚未通过实验发现¹³⁶ Xe的双β衰变到¹³⁶ Ba的激发态（DBD-ES）。借助拓扑信号，可以在气体检测器中更有效地识别此类衰减的实验信号，即继β信号后的一两个伽玛射线。我们以提出的PandaX-III探测器的蒙特卡罗模拟数据为例，研究了DBD-ES粒子轨迹的关键参数。可以将本底速率降低大约一个数量级，同时通过拓扑分析保留一半以上的信号。DBD-ES的估计半衰期敏感性可以提高1.8倍，达到4.1×10 ²³年（CL的90％）。同样，可以将¹³⁶ Xe的无中微子双β衰变对¹³⁶ Ba激发态的半衰期敏感性提高4.8倍，并具有拓扑特征。