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Related papers: $\Lambda(1405)$ mediated triangle singularity in t…

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We evaluate the threshold matrix-element for the reaction $pp \to pp\pi^0$ in a fully relativistic Feynman diagrammatic approach. We employ a simple effective range approximation to take care of the S-wave $pp$ final-state interaction. The…

Nuclear Theory · Physics 2009-10-31 V. Bernard , N. Kaiser , Ulf-G. Meißner

This work is dedicated to the search for a $\pi\Lambda N\!-\!\pi\Sigma N$ resonance $\mathcal{Y}$ with the quantum numbers ($Y,I,J^P$) = (1,3/2,$2^+$). The double charged $\Sigma(1385)N\!-\!\Delta(1232)Y$ quasibound state was looked for in…

Nuclear Experiment · Physics 2014-10-30 J. C. Berger-Chen , L. Fabbietti

The processes involving low energy $\bar{K}N$ and $Y\pi$ interactions (where $Y= \Sigma$ or $\Lambda$) are studied in the framework of heavy baryon chiral perturbation theory with the $\Lambda$(1405) resonance appearing as an independent…

Nuclear Theory · Physics 2008-11-26 B. Krippa , J. T. Londergan

We investigate Lambda(1520,3/2^-,D_03) photoproduction via the gamma N -> K Lambda^* reaction process. Using effective Lagrangians, we compute the total and differential cross sections as well as the dependence on the momentum transfer for…

High Energy Physics - Phenomenology · Physics 2009-12-17 Seung-Il Nam , Atsushi Hosaka , Hyun-Chul Kim

In this study, applying the effective Lagrangian approach, we investigate the reaction $\pi^-p\rightarrow K^{*}\Sigma$ to explore the production of the hidden-strange molecular pentaquarks $P_{s\bar{s}}$. Specifically, we analyze two…

High Energy Physics - Phenomenology · Physics 2025-02-17 Xiao-Yun Wang , Yuan Gao , Xiang Liu

Exclusive data on the reactions pp -> ppK+K- and pp -> pK+ Lambda/Sigma0 have been taken at the cooler synchrotron COSY close to threshold. At equal excess energies, an enhancement of the Lambda/Sigma0 ratio by one order of magnitude has…

In this work, the triangle singularity mechanism is investigated in the $\psi(2S) \to p \bar{p} \eta / p \bar{p} \pi^0$ process. The triangle loop composed by $J/\psi$, $\eta$ and $p$ has a singularity in the physical kinematic range for…

High Energy Physics - Phenomenology · Physics 2021-05-21 Qi Huang , Chao-Wei Shen , Jia-Jun Wu

The K^- p --> pi^0 pi^0 Sigma^0 reaction is studied within a chiral unitary model. The distribution of pi^0 Sigma^0 states forming the Lambda(1405) shows, in agreement with a recent experiment, a peak at 1420 MeV and a relatively narrow…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. K. Magas , E. Oset , A. Ramos

With the advent of high precision proton accelerators, such as COSY in J\"ulich, or with medium energy accelerators like RCNP at Osaka, it may become possible to perform a direct study of the strangeness changing hadronic $np \to \Lambda p$…

Nuclear Theory · Physics 2007-05-23 A. Parreño , A. Ramos , N. G. Kelkar , C. Bennhold

The octet meson and baryon interaction with strangeness $S=-1$ is studied fully relativistically with chiral Lagrangian. In this work, a Bethe-Salpeter equation approach with spectator quasipotential approximation is applied to study the…

Nuclear Theory · Physics 2015-12-04 Jun He , Pei-Liang Lu

The reaction pp -> K+ + (Lambda p) was measured at Tp=1.953 GeV and Theta = 0 deg with a high missing mass resolution in order to study the Lambda p final state interaction. The large final state enhancement near the Lambda p threshold can…

Meson-baryon interactions are the fundamental building blocks to study the structures of baryon resonances and meson properties in few-body nuclear systems. We review the recent progress in the investigation of the meson-baryon interaction…

Nuclear Theory · Physics 2011-08-31 Tetsuo Hyodo

The Ultra-relativistic Quantum Molecular Dynamics model is employed to simulate $\pi^-+\mathrm{C}$ and $\pi^-+\mathrm{W}$ collisions at p$_\mathrm{lab}=1.7$ GeV motivated by the recent HADES results. By comparing the proton and $\Lambda$…

The missing mass spectrum measured in high resolution studies of the reaction pp -> K^+X is analyzed with respect to the strong final state interaction near the Lambda p production threshold. The observed spectrum can be described by…

Nuclear Experiment · Physics 2009-11-10 F. Hinterberger , A. Sibirtsev

The role of the low lying nucleon resonances beyond the $\Delta(1232)$ in the reaction $pp\to pp\pi^0$ near threshold is shown to be numerically significant by a calculation, which takes into account the pion re-scattering contribution…

Nuclear Theory · Physics 2009-10-31 M. T. Peña , D. O. Riska , A. Stadler

We analyse the $pp \to p \Lambda K$ cross section recently measured at COSY arguing that the enhancement of the production cross section at energies close to the reaction threshold should be due to the $\Lambda p$ final state interaction.…

Nuclear Theory · Physics 2007-05-23 A. Sibirtsev , W. Cassing

The production of the Sigma+ hyperon through the pp->K+nSigma+ reaction has been investigated at four energies close to threshold, 1.826, 1.920, 1.958, and 2.020 GeV. At low energies, correlated K+pi+ pairs can only originate from Sigma+…

The reaction p(@3.5\,GeV)+p -> p+\Lambda + K^+ can be studied to search for the existence of kaonic bound states like ppK^- leading to this final state. This effort has been motivated by the assumption that in p+p collisions the…

We investigate the mechanisms of strangeness production in the $\pi^- p \to K^{*0} \Sigma^0$ and $\pi^- p \to K^{*+} \Sigma^-$ reactions within a hybrid Regge framework in which effective Lagrangian vertices are combined with Reggeized…

High Energy Physics - Phenomenology · Physics 2026-04-02 Sang-Ho Kim

Pion and photo-induced inelastic reactions off protons are studied in a multichannel partial-wave analysis. Properties of nucleon and $\Delta$ resonances are derived and compared to previous analyses. Amplitudes are shown for transitions to…

Nuclear Theory · Physics 2015-06-05 A. V. Anisovich , R. Beck , E. Klempt , V. A. Nikonov , A. V. Sarantsev , U. Thoma