Detecting the barium daughter in 136Xe 0-νββ decay using single-molecule fluorescence imaging techniques

7th International Symposium on Large TPCs for Low-Energy Rare Event Detection

Nygren, David R.^1

Department of Physics, University of Texas at Arlington, Box 19059, Arlington

TX

76015, United States^1

关键词: Alkaline-earth elements;    Double beta decay;    Electron trajectories;    Fluorescent imaging;    High pressure xenon;    Photo-excitations;    Precursor molecules;    Specific detection;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/650/1/012002/pdf
DOI  :  10.1088/1742-6596/650/1/012002

来源: IOP

【 摘 要 】

Single-molecule fluorescent imaging may provide an avenue to efficiently detect the Ba++daughter atom in the decay136Xe → Ba + 2e-, and, unambiguously associate the birth point in space within the electron trajectories of the decay event. Chelation of doubly-charged alkaline earth elements such as calcium and barium by certain precursor molecules converts the resulting complex from a non-fluorescent to a fluorescent state. Repeated photo-excitation of a single fluorescent complex reveals both presence and location with high precision. This technique, widespread now in biochemistry, biophysics and biology, may permit a similar discriminating response in a large high-pressure xenon gas TPC for the Ba++ion from xenon double-beta decay. The TPC measures the event time and energy of the two nascent electrons, as well as topology and position in 3-D from their trajectories in the gas. Measurement of the 2-D location of the molecular ion after arrival at the cathode plane permits an association of ion with the event. Demonstration of an efficient, highly specific detection of the barium daughter would provide a long-sought pathway to a background-free result in the search for this decay mode, of central importance for determining the nature of the neutrino.