论文标题
观察$ \ bar {k} nn $绑定状态在$^3 {\ rm he}（k^ - ，λp）n $反应
Observation of a $\bar{K}NN$ bound state in the $^3{\rm He} (K^-, Λp)n$ reaction
论文作者
论文摘要
我们已经对$ k^{ - }+\进行了独家测量。 〜^^{3} {\ rm he} \toλpn$在事件的kaon动量中反应$ 1 \ {\ rm gev}/c$。状态，$ \ bar {k} nn $。观察到这种状态的绑定能量，衰减宽度和$ s $ - 波的高斯反应形式为$ b_ {k {k {k {k {{\ rmStat。} {\ rm Stat。}） $γ_{k} = 100 \ pm7（{\ rm Stat。}）^{+19} _ { - 9}（{\ rm syst。}）\ {\ rm mev} $，和$ q_ {k {k} stat。}）^{+4} _ { - 1}（{\ rm syst。}）\ {\ rm mev}/c $。由$λp$衰减模式确定的$ \ bar {k} nn $的总生产横截面为$σ^{tot} _ {k} \ cdot br_ {λp} = 9.3 \ pm0.8（{\ rm Stat。}。 μ{\rm b}$.We estimated the branching ratio of the $\bar{K}NN$ state to the $Λp$ and $Σ^{0}p$ decay modes as $BR_{Λp}/BR_{Σ^{0}p} \sim 1.7$, by assuming that the physical processes leading to the $ΣN\!N$ final states are类似于$λpn$的类似。
We have performed an exclusive measurement of the $K^{-}+\! ~^{3}{\rm He} \to Λpn$ reaction at an incident kaon momentum of $1\ {\rm GeV}/c$.In the $Λp$ invariant mass spectrum, a clear peak was observed below the mass threshold of $\bar{K}\!+\!N\!+\!N$, as a signal of the kaonic nuclear bound state, $\bar{K}NN$.The binding energy, decay width, and $S$-wave Gaussian reaction form-factor of this state were observed to be $B_{K} = 42\pm3({\rm stat.})^{+3}_{-4}({\rm syst.})\ {\rm MeV}$, $Γ_{K} = 100\pm7({\rm stat.})^{+19}_{-9}({\rm syst.})\ {\rm MeV}$, and $Q_{K} = 383\pm11({\rm stat.})^{+4}_{-1}({\rm syst.})\ {\rm MeV}/c$, respectively. The total production cross-section of $\bar{K}NN$, determined by its $Λp$ decay mode, was $σ^{tot}_{K} \cdot BR_{Λp} = 9.3\pm0.8({\rm stat.})^{+1.4}_{-1.0}({\rm syst.})\ μ{\rm b}$.We estimated the branching ratio of the $\bar{K}NN$ state to the $Λp$ and $Σ^{0}p$ decay modes as $BR_{Λp}/BR_{Σ^{0}p} \sim 1.7$, by assuming that the physical processes leading to the $ΣN\!N$ final states are analogous to those of $Λpn$.
