论文标题
$ p^λ_{ψs}（4459）$和$ p^λ_{ψs}（4338）$作为$ j/ψλ$不变质谱的分子状态
$P^Λ_{ψs}(4459)$ and $P^Λ_{ψs}(4338)$ as molecular states in $ J/ψΛ$ invariant mass spectra
论文作者
论文摘要
最近，LHCB合作报告了两个奇怪的隐藏式链式五角夸克州，名为$ p^λ_{ψs}（4459）$和$ p^λ_{ψs}（4338）$ $ b^ - $$ \ to $$ j/ψλ\ bar {p} $。在这项工作中，我们对交互的耦合通道研究$ξ_c^*\ bar {d}^*$，$蒜$λ_C\ bar {d} _s^{*} $，$ξ_c\ bar {d} $，$λ_c\ bar {d} _s $和$λj/ψ$在Quasipotential bethe-salpeter方程中的方法，以估算$ j/ψ单spemairt $ j/ψλ$ invariant spempra。借助有效的Lagrangians，可以通过介子交换来构建潜在的内核，以获得散射幅度，可以从中达到结合状态的极点和不变的质谱。耦合通道计算会导致状态$ξ_c\ bar {d}^{*}（1/2^ - ）$的宽度约为$ 18 $ 〜MEV，并且状态$ξ_c\ bar {d}^}^{*}^}^}^}（3/2^ - ）$仅大约$ 1.6 $ 〜Mev。通过与实验数据进行比较，它表明结构$ p^λ_{ψs}（4459）$主要来自$ξ_c\ bar {d}^{*}^{*}（1/2^ - ）$的贡献。结构的线形$ p^λ_{ψs}（4338）$可以通过$ξ_c\ bar {d} $与$ j^p $ = $ 1/2^ - $相互作用的狭窄分子状态大致复制。此外，建议在$ j/ψλ$不变质量频谱中观察到一个额外的状态$ξ'_c\ bar {d}（1/2^ - ）$。
Recently, the LHCb Collaboration has reported two strange hidden-charm pentaquark states named $P^Λ_{ψs}(4459)$ and $P^Λ_{ψs}(4338)$ in the $ J/ψΛ$ invariant mass spectra of decays $Ξ_b^-$$\to$$ J/ψΛK^-$ and $B^-$$\to$$J/ψΛ\bar{p}$,respectively. In this work, we perform a coupled-channel study of the interactions $Ξ_c^*\bar{D}^*$, $Ξ'_c\bar{D}^*$, $Ξ^*_c\bar{D}$, $Ξ_c\bar{D}^*$, $Ξ'_c\bar{D}$, $Λ_c\bar{D}_s^{*}$, $Ξ_c\bar{D}$, $Λ_c\bar{D}_s$, and $ΛJ/ψ$ in the quasipotential Bethe-Salpeter equation approach to estimate the $ J/ψΛ$ invariant mass spectra. With the help of effective Lagrangians, the potential kernel can be constructed by meson exchanges to obtain the scattering amplitudes, from which the poles of the bound states and the invariant mass spectra can be reached. The coupled-channel calculation results in that the width of state $Ξ_c\bar{D}^{*}(1/2^-)$ is about $18$~MeV and that of state $Ξ_c\bar{D}^{*}(3/2^-)$ is only about $1.6$~MeV. By comparison with experimental data, it indicates that the structure $P^Λ_{ψs}(4459)$ is mainly from the contribution from the $Ξ_c \bar{D}^{*}(1/2^-)$ state while the role of state $Ξ_c \bar{D}^{*}(3/2^-)$ cannot be excluded. The line shape of the structure $P^Λ_{ψs}(4338)$ can be reproduced roughly by a narrow molecular state from the $Ξ_c \bar{D}$ interaction with $J^P$=$1/2^-$, which is extremely close to the threshold, with a large interference effect. Besides, an additional state $Ξ'_c \bar{D}(1/2^-)$ is suggested to be observed as a dip structure in the $J/ψΛ$ invariant mass spectrum.
