The strong ΛbNB\Lambda_bNB and ΛcND\Lambda_cND vertices

We investigate the strong vertices among $\Lambda_b$, nucleon and $B$ meson as well as $\Lambda_c$, nucleon and $D$ meson in QCD. In particular, we calculate the strong coupling constants $g_{\Lambda_bNB}$ and $g_{\Lambda_cND}$ for different Dirac structures entered the calculations. In the case of $\Lambda_cND$ vertex, the result is compared with the only existing prediction obtained at $Q^2=0$.Comment: 12 Pages, 3 Figures and 4 Table

On the strong coupling N(∗)N(∗)πN^{(*)}N^{(*)}\pi

We study the strong vertices $N^*N\pi$, $N^*N^*\pi$ and $NN\pi$ in QCD, where $N^*$ denotes the negative parity $N (1535)$ state. We use the most general form of the interpolating currents to calculate the corresponding strong coupling constants. It is obtained that the coupling associated to $N^*N\pi$ vertex is strongly suppressed compared to those related to two other vertices. The strong coupling corresponding to $N^*N^*\pi$ is obtained to be roughly half of that of $NN\pi$ vertex. We compare the obtained results on $N^*N\pi$ and $NN\pi$ vertices with the existing predictions of other theoretical studies as well as those extracted from the experimental data.Comment: 15 Pages, 4 Figures and 3 Table

Strong couplings of negative and positive parity nucleons to the heavy baryons and mesons

The strong coupling form factors related to the strong vertices of the positive and negative parity nucleons with the heavy $\Lambda_{b[c]}[\Sigma_{b[c]}]$ baryons and heavy $B^*[D^*]$ vector mesons are calculated using a three-point correlation function. Using the values of the form factors at $Q^2=-m^2_{meson}$ we compute the strong coupling constants among the participating particles.Comment: 12 Pages and 7 Table

Investigation of a candidate spin-12\frac{1}{2} hidden-charm triple strange pentaquark state PcsssP_{csss}

A candidate triple strange pentaquark state, $P_{csss}$, is investigated through its strong decay channel $P_{csss} \rightarrow \Omega^-J/\psi$. To calculate the relevant strong coupling constants, two possible interpolating currents with spin-parity $J^P=\frac{1}{2}^{-}$ are used. Though the chosen currents for the state under consideration have spin-parity quantum numbers $J^P=\frac{1}{2}^{-}$, they couple to both the positive and negative parity states simultaneously and the corresponding decay widths are obtained for both parities. These widths are obtained as follows: $\Gamma(P_{csss} \rightarrow J/\psi \Omega^-)=201.4\pm 76.7~\mathrm{MeV}$ for the negative and $\Gamma(\widetilde{P}_{csss} \rightarrow J/\psi \Omega^-)=316.4\pm 100.3~\mathrm{MeV}$ for the positive parity state when the first current is used. For the second current, we obtain $\Gamma(P_{csss} \rightarrow J/\psi \Omega^-)=252.5\pm 108.6~\mathrm{MeV}$ for the negative and $\Gamma(\widetilde{P}_{csss} \rightarrow J/\psi \Omega^-)=361.1\pm 88.2~\mathrm{MeV}$ for the positive parity state. These results may provide insights into future experimental observations of such candidate states and help to distinguish and fix their properties.Comment: 13 Pages and 3 Table

Investigation of Λ(1405)\Lambda(1405) as a molecular pentaquark state

$\Lambda(1405)$ is one of the interesting particles with its unclear structure and distinct properties. It has a light mass compared to its non-strange counterpart, despite the strange quark it carries. This situation puts investigation of this resonance among the hot topics in hadron physics and collects attentions to clarify its properties. In this study, we focus on the calculation of the mass and residue of the $\Lambda(1405)$ resonance within the framework of QCD sum rules. We assign a structure in the form of molecular pentaquark composed of a $K^-$ meson and a proton. Using an interpolating current in this form, the mass and the current coupling constant are attained as $m=1406\pm 128~\mathrm{MeV}$ and $\lambda=(3.35\pm 0.35)\times10^{-5}~\mathrm{GeV}^6$, respectively. The obtained mass value agrees well with the experimental data supporting the plausibility of the considered structure.Comment: 8 Pages, 2 Figures and 1 Tabl

Investigation of the strange pentaquark candidate PψsΛ(4338)0P_{\psi s}^{\Lambda}(4338){}^0 recently observed by LHCb

The recently observed strange pentaquark candidate, $P_{\psi s}^{\Lambda}(4338){}^0$, is investigated to provide information about its nature and substructure. To this end, its mass and width through the decay channels $P_{\psi s}^{\Lambda}(4338){}^0 \rightarrow J/\psi \Lambda$ and $P_{\psi s}^{\Lambda}(4338){}^0 \rightarrow \eta_c \Lambda$ are calculated by applying two- and three-point QCD sum rules, respectively. The state is considered as a $\Xi_c\bar{D}$ meson-baryon molecular structure with spin-parity quantum numbers $J^P=\frac{1}{2}^-$. The obtained mass, $m_{P_{\psi s}^{\Lambda}(4338){}^0}=4338\pm 130~\mathrm{MeV}$, and width, $\Gamma_{P_{\psi s}^{\Lambda}(4338){}^0}= 10.40\pm 1.93~\mathrm{MeV}$, are consistent with the experimental data within the presented uncertainties. This allows us to assign a $\Xi_c\bar{D}$ molecular structure of $J^P=\frac{1}{2}^-$ for the $P_{\psi s}^{\Lambda}(4338){}^0$ state.Comment: 14 Pages, 2 Figures and 2 Table