标题： 对33.9 MeV/c^2 同位旋单态中微子的实验室限制：现状与前景 显示英文标题

标题： Laboratory Constraints on a 33.9 MeV/c^2 Isosinglet Neutrino: Status and Perspectives

摘要： 观测到的KARMEN合作组信号的时间行为中的异常可能被解释为33.9 MeV/c$^2$主要惰性中微子的可能衰变特征。 本说明讨论了这种假设粒子与已知轻子味中微子混合的仍开放的参数空间，考虑了最近获得的实验结果以及预期的未来测量结果。 结论是，如果未观察到积极的特征，则预期的实验室实验不会完全关闭混合幅度的参数空间。 然而，对ALEPH给出的$\nu_\tau$中微子质量上限进行重新评估，包括$\tau$面味混合的可能性，无疑有助于缩小开放的参数空间。 显示英文摘要

摘要： An anomaly in the time behaviour of the signals observed by the KARMEN Collaboration may be interpreted as the possible decay signature of a 33.9 MeV/c$^2$ mainly sterile neutrino. This note discusses the parameter space still open for the mixing of this hypothetical particle with the neutrinos of known leptonic flavour, considering the experimental results which became available recently, as well as those to be expected from forthcoming measurements. It is concluded that if no positive signature is observed, the envisaged laboratory experiments are not expected to close enterily the parameter space of mixing amplitudes. However, a proper reassessment of the ALEPH upper bound on the $\nu_\tau$ neutrino mass including the possibility of $\tau$ flavour mixing, would certainly help in reducing the parameter space left open.