Virtual depth by active background suppression: revisiting the cosmic muon induced background of Gerda Phase II
Virtual depth by active background suppression: revisiting the cosmic muon induced background of Gerda Phase II
复制标题
DOI：
10.1140/epjc/s10052-018-6079-3
复制
发表时间：
2018-02
期刊：
影响因子：
--
通讯作者：
C. Wiesinger;L. Pandola;S. Schönert
中科院分区：
文献类型：
--
作者：
C. Wiesinger;L. Pandola;S. Schönert
通过宇宙μ子相互作用原位产生放射性同位素可能会为深层地下稀有事件搜索产生不可忽略的背景。以前的蒙特卡罗研究在Lng的格尔达实验中发现，在寻找Ge的无中微子双β衰变时，Ge的延迟衰变及其亚稳态Ge是占主导地位的宇宙成因背景。这可能会限制下一代实验的灵敏度，目的是在无背景条件下增加Ge质量，从而定义最低深度要求。用一组Monte Carlo模拟方法对Gerda实验的Ge本底进行了重新评价。Ge的产率为（）个核/（kg·年）。在应用最先进的主动背景抑制技术和简单的延迟符合切割之后，这对应于cts/（keVkgyear）的背景贡献。通过这种策略实现的抑制相当于一个有效的μ子通量减少超过一个数量级。这种虚拟深度的增加为下一代罕见事件搜索开辟了道路。
In-situ production of radioisotopes by cosmic muon interactions may generate a non-negligible background for deep underground rare event searches. Previous Monte Carlo studies for theGerdaexperiment atLngsidentified the delayed decays ofGe and its metastable stateGe as dominant cosmogenic background in the search for neutrinoless double beta decay ofGe. This might limit the sensitivity of next generation experiments aiming for increasedGe mass at background-free conditions and thereby define a minimum depth requirement. A re-evaluation of theGe background for theGerdaexperiment has been carried out by a set of Monte Carlo simulations. The obtainedGe production rate is () nuclei/(kgyear). After application of state-of-the-art active background suppression techniques and simple delayed coincidence cuts this corresponds to a background contribution ofcts/(keVkgyear). The suppression achieved by this strategy equals an effective muon flux reduction of more than one order of magnitude. This virtual depth increase opens the way for next generation rare event searches.