论文标题
在$ k^+$衰减上搜索重型中性Lepton生产
Search for heavy neutral lepton production in $K^+$ decays to positrons
论文作者
论文摘要
报告了使用NA62实验在CERN在2017---2018的NA62实验收集的数据样本中搜索$ k^+\ to $ k^+\ to e^+n $衰变的重型中性Lepton（$ n $）的搜索。扩展中微子混合矩阵元素$ | u_ {e4} |^2 $在大多数可访问的重型中性Lepton质量范围144---462 mev/$ c^2 $上以$ 10^{ - 9} $的水平建立，并假定其寿命超过50 ns。这些限制在先前的生产和衰减搜索方面大大提高。 $ | u_ {e4} |^2 $ range由大爆炸核合成所偏爱的范围被排除在大约340 meV/$ c^2 $的质量上。
A search for heavy neutral lepton ($N$) production in $K^+\to e^+N$ decays using the data sample collected by the NA62 experiment at CERN in 2017--2018 is reported. Upper limits of the extended neutrino mixing matrix element $|U_{e4}|^2$ are established at the level of $10^{-9}$ over most of the accessible heavy neutral lepton mass range 144--462 MeV/$c^2$, with the assumption that the lifetime exceeds 50 ns. These limits improve significantly upon those of previous production and decay searches. The $|U_{e4}|^2$ range favoured by Big Bang Nucleosynthesis is excluded up to a mass of about 340 MeV/$c^2$.
