论文标题
在衰减中搜索微弱的交互粒子$ x $
Search for a feebly interacting particle $X$ in the decay $K^{+}\rightarrowπ^{+}X$
论文作者
论文摘要
搜索$ k^{+} \rightArrowπ^{+} x $衰减，其中$ x $是长期寿命的微弱相互作用的粒子，是通过解释$ k^{+rightArrowπ^{+rightArrowπ^{+} c {+}ν{+}ν\barν$分析Na62 cern cern cern cern cern cern cern cern cern cern cern of na62 cern cern。 $ x $ asses的两个范围，$ 0 $ - $ 110 \，\ text {mev}/c^{2} $和$ 154 $ - $ 260 \，\ text {mev}/c^{2} $，以及$ 100 \，$ 100 \，\ text {ps} $。设定的分支比率，$ \ text {br}（k^{+} \rightarrowπ^{+} x）$具有竞争力，在第一个质量范围内先前报道的搜索，并且在第二质量范围内的搜索范围提高了，而在第二质量范围内的限制提高了超过一个数量级。
A search for the $K^{+}\rightarrowπ^{+}X$ decay, where $X$ is a long-lived feebly interacting particle, is performed through an interpretation of the $K^{+}\rightarrowπ^{+}ν\barν$ analysis of data collected in 2017 by the NA62 experiment at CERN. Two ranges of $X$ masses, $0$-$110\,\text{MeV}/c^{2}$ and $154$-$260\,\text{MeV}/c^{2}$, and lifetimes above $100\,\text{ps}$ are considered. The limits set on the branching ratio, $\text{BR}(K^{+}\rightarrowπ^{+}X)$, are competitive with previously reported searches in the first mass range, and improve on current limits in the second mass range by more than an order of magnitude.
