论文标题
$λ（1405）$ hyperon to $σ^0π^0 $的衰减
Decay of the $Λ(1405)$ Hyperon to $Σ^0π^0$ Measured at GlueX
论文作者
论文摘要
在轻baryon中，$ j^π= \ frac {1} {2}^ - $ $ $ $ $ $ up，$ hyperon是一个重要的特殊情况，因为它位于$ n \ bar {k} $ threshold以下，并且几乎完全衰减至$九$σπ$。 $λ（1405）$的一些长期存在的假设是，它可能是$ n \ bar {k} $绑定状态或$σπ$连续共振。它也可以被认为是简单的夸克模式共振，$λ（1520）$的$ p $ - 波伴侣。近年来，手性统一模型表明，该质量区域中存在两个同源零极点，并且$λ（1405）$的“线形状”取决于在给定反应中刺激两个杆子中的每个杆的何种程度。在$ n \ bar {k} $阈值下方，$λ（1405）$衰减到三个$σπ$电荷组合。 $σ^{0}π^{0} $模式纯粹是$ i = 0 $，并且没有由$ i = 1 $散射过程引起的复杂性，这些散射过程会导致$σ^{+}+}π^{ - } $ and $σ^{ - } $ and $σ^^^^{ - }^{ - }π^^{+decays的反应机制。它也不会受到附近$σ^{0}（1385）$ hyperon的生产和衰减的影响。 Jefferson Lab的Gluex实验已用于研究$λ（1405）\至σ^{0}π^{0} $衰减模式。我们专注于$dσ/dm_ {σ^{0}π^{0}} $的初步结果，并符合$ - （t-t_ {min}）$ - 范围0-1.5 gev $^2 $的$ - （t-t_ {min}）中的$λ（1405）$ region的线形状$ culterty $ culterty $ culterty $ cultery offerty $ - Gluex程序。
Among the light baryons, the $J^π= \frac{1}{2}^-$ $Λ(1405)$ hyperon is an important special case as it sits just below the $N\bar{K}$ threshold and decays almost exclusively to $Σπ$. Some long-standing hypotheses for $Λ(1405)$ are that it could be a $N\bar{K}$ bound state or a $Σπ$ continuum resonance. It may also be considered as a simple quark-model resonance, the $P$-wave companion of the $Λ(1520)$. In recent years chiral unitary models have suggested that there are two isospin zero poles present in this mass region, and that the "line shape" of the $Λ(1405)$ depends to what extent each of the two poles are stimulated in a given reaction. Below the $N\bar{K}$ threshold, the $Λ(1405)$ decays to the three $Σπ$ charge combinations. The $Σ^{0}π^{0}$ mode is purely $I=0$ and it is uncontaminated by complications arising from $I=1$ scattering processes contributing to the reaction mechanism in the $Σ^{+}π^{-}$ and $Σ^{-}π^{+}$ decays. It is also not affected from production and decay of the nearby $Σ^{0}(1385)$ hyperon. The GlueX experiment at Jefferson Lab has been used to study the $Λ(1405) \to Σ^{0}π^{0}$ decay mode. We focus on the preliminary results of $dσ/dM_{Σ^{0}π^{0}}$ and fits to the line shape of the $Λ(1405)$ region in the $-(t-t_{min})$ range 0 - 1.5 GeV$^2$ from analyzing the reaction $γp \to K^{+}Λ^*$ using the data collected during the first phase of the GlueX program.
