Role of a triangle singularity in the $\gamma p\to K^{+}\Lambda (1405)$ reaction

Abstract

We show the effects of a triangle singularity mechanism for the $\gamma p\to K^{+}\Lambda (1405)$ reaction. The mechanism has a $N^{\ast }$ resonance around 2030 MeV, which decays into $K^{\ast }\Sigma$. The $K^{\ast }$ decays to $K^{+}\pi$, and the $\pi \Sigma$ merge to form the $\Lambda (1405)$. This mechanism produces a peak around $\sqrt{s}=2110$ MeV, and has its largest contribution around cos$\theta =0$. The addition of this mechanism to other conventional ones, leads to a good reproduction of $\mathrm{d}\sigma /\mathrm{dcos}\theta$ and the integrated cross section around this energy, providing a solution to a problem encountered in previous theoretical models.

10 pages, 10 figures

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Cited by in corpus (21)

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• Triangle singularity in the $B^{-}\to K^{-}{\pi }^{0}X(3872)$ reaction and sensitivity to the $X(3872)$ mass
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• $f_2(1810)$ as a triangle singularity
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• Effects of $N(2000){5/2}^{+}$ on $\gamma p\to K^{+}\Lambda (1405)$
• Effects of Final State Interactions on Landau Singularities
• Photo-production of lowest ${\Sigma }_{1/2^{-}}^{\ast }$ state within the Regge-effective Lagrangian approach
• Detecting the pure triangle sigularity effect through the $\psi (2S)\to p\bar{p}\eta /p\bar{p}{\pi }^0$ process
• Photo- and electroproduction of $\Lambda (1405)$ via ${\gamma }^{(\ast )}p\to K^{+}{\pi }^{+}{\Sigma }^{-}$
• The role of triangle singularity in isospin breaking process $J/\psi \to \Lambda \bar{\Lambda }\pi$ and the possible evidence of ${\Sigma }^{\ast }({\frac{1}{2}}^{-})$ states
• Studying triangle singularity through spin observables
• Enhancement near the $\bar{p}\Lambda$ threshold in the ${\chi }_{c0}\to \bar{p}{K}^{+}\Lambda$ reaction
• The role of triangle singularity in the decay process $D^0\to {\pi }^{+}{\pi }^{-}{f}_0(980),f_0\to {\pi }^{+}{\pi }^{-}$
• Triangle mechanism in the decay process $B_0\to J/\psi K^0{f}_0(980)(a_0(980))$
• Producing $\Lambda (1405)$ and $\Lambda (1520)$ in ${\pi }^{-}p$ reaction to explore their inner structures
• Photoproduction $\gamma p\to K^{+}\Lambda (1690)$ in an effective Lagrangian approach
• Box Singularity Conditions in Box Diagrams of Decay Processes