Related papers: Detecting the pure triangle sigularity effect thro…

In this work, we study the role of triangle singularity in the $J/\psi \to \gamma \bar{p} \Delta$ decay. We find that through a triangle mechanism, involving a triangle loop composed by $\omega$, $\pi$ and $p$, this decay may develop a…

We have analyzed the singularities of a triangle loop integral in detail and derived a formula for an easy evaluation of the triangle singularity on the physical boundary. It is applied to the $\Lambda_b \rightarrow J/\psi K^{-} p$ process…

In this work, we propose that there exists a moving triangle singularity in the $\psi(2S) \to \pi^+ \pi^- K^+ K^-$ process, whose position can vary from 1.158 to 1.181 GeV in the invariant mass spectrum of $K^+K^-$. After a precise analysis…

In this study, the impact of triangle singularity is investigated in the isospin-breaking process $J/\psi \to \Lambda \bar{\Lambda} \pi$. The triangle singularity is found to play a significant role in the process, resulting in the creation…

We have investigated the cross section for the $\pi^-p\rightarrow K^0\pi\Sigma$ and $pp\rightarrow pK^+\pi\Sigma$ reactions paying attention to a mechanism that develops a triangle singularity. The triangle diagram is realized by the decay…

We consider a triangle diagram for $B^0\to (J/\psi\pi^+\pi^-) K^+\pi^-$ where an $X(3872)$ peak has been observed experimentally. We demonstrate that a triangle singularity inherent in the triangle diagram creates a sharp peak in the…

We study the $J/\psi \to \phi \pi^+ a_0(980)^- (a_0^- \to \pi^- \eta)$ decay, evaluating the double mass distribution in terms of the $\pi^- \eta$ and $\pi^+ a^-_0$ invariant masses. We show that the $\pi^- \eta$ mass distribution exhibits…

We analyze possible singularities in the $J/\psi \Lambda$ invariant mass distribution of the $\Xi^-_{b}~\to~K^- J/\psi \Lambda$ process via triangle loop diagrams. Triangle singularities in the physical region are found in 18 different…

We investigate the process $B\to \bar{D}D_s \pi$ via several rescattering processes. It is shown that the triangle singularity (TS) peak around the $D^*K^*$ threshold generated from the $\chi_{c1}K^* D^*$ loop is relatively narrow, which…

We have studied the $\gamma p \to p \pi^0 \eta$ reaction paying attention to the two main mechanisms at low energies, the $\gamma p \to \Delta(1700) \to \eta \Delta(1232)$ and the $\gamma p \to \Delta(1700) \to \pi N(1535)$. Both of them…

We study the $\Lambda^+_c \to \pi^0 \phi p$ decay by considering a triangle singularity mechanism. In this mechanism, the $\Lambda^+_c$ decays into the $K^* \Sigma^*(1385)$, the $\Sigma^*(1385)$ decays into the $\pi^0 \Sigma$ (or…

In this work, we study the spin density matrix element $\rho_{00}$ of the $\phi$ in the decay $J/\psi \rightarrow \eta \pi \phi$. In previous studies, a band around 1.4 GeV on the $\pi^0\phi$ distribution in Dalitz plot was reported by the…

In this article, the analyticity of triangle loop integral with complex masses of internal particles is discussed in a new perspective, base on which we obtain the explicit width dependence of the absorptive part of the triangle amplitude.…

Triangle mechanisms for $B^0\to (J/\psi\pi^+\pi^-) K^+\pi^-$ are studied. Experimentally, an $X(3872)$ peak has been observed in this process. When the final $(J/\psi\pi^+\pi^-)\pi$ invariant mass is around the $D^*\bar D^*$ threshold, one…

We present a model for the $J/\psi\Lambda$ spectrum in $B^-\to J/\psi \Lambda \bar{p}$ decays, including the $P_{\psi s}^\Lambda(4338)$ baryon recently observed by the LHCb collaboration. We assume production via triangle diagrams which…

It was proposed that the narrow $P_c(4450)$ structure observed by the LHCb Collaboration in the reaction $\Lambda_b\to J/\psi p K$ might be due to a triangle singularity around the $\chi_{c1}$--proton threshold at 4.45~GeV. We discuss the…

The BES-III Collaboration recently report the observation of anomalously large isospin violations in $J/\psi\to \gamma\eta(1405/1475) \to \gamma \pi^0 f_0(980)\to \gamma +3\pi$, where the $f_0(980)$ in the $\pi\pi$ invariant mass spectrum…

We show the effects of a triangle singularity mechanism for the $\gamma p \to K^+\Lambda(1405)$ reaction. The mechanism has a $N^*$ resonance around 2030 MeV, which decays into $K^* \Sigma$. The $K^*$ decays to $K^+ \pi$, and the $\pi…

The role of triangle mechanism in the decay process $J/\psi \to K^- K^+ a_1(1260)$ is probed. In this mechanism, a close-up resonance with mass $1823$ MeV and width $122$ MeV decays into $K^* \phi, K^* \to K \pi$ and then $K^* \bar{K}$…

In this work, we investigate the resonance production in $\Lambda^+_c \to \gamma \pi^+ \Lambda$ decay through the triangle singularity (TS) mechanism, within an effective Lagrangian approach. We find that the appropriate loop decay process…