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Related papers: Testing chiral unitary models for the $\Lambda(140…

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We report on a recent theoretical work on the structure of the Lambda(1405) resonance within a chiral unitary approach, in which the resonance is dynamically generated in meson-baryon scattering. Studying the analytic structure of the…

High Energy Physics - Phenomenology · Physics 2009-11-11 D. Jido , J. A. Oller , E. Oset , A. Ramos , U. -G. Meissner

We identify the leading s-wave amplitudes of the SU(3) chiral meson-baryon Lagrangian with an effective coupled-channel potential which is iterated in a Lippmann-Schwinger equation. The strangeness $S=-1$ resonance $\Lambda(1405)$ and the…

High Energy Physics - Phenomenology · Physics 2016-09-06 N. Kaiser , T. Waas , W. Weise

We calculate in chiral perturbation theory the double-pion photoproduction processes $\pi^-\gamma \to \pi^- \pi^0\pi^0$ and $\pi^-\gamma\to \pi^+\pi^-\pi^-$ at low energies. At leading order these reactions are governed by the chiral…

High Energy Physics - Phenomenology · Physics 2011-03-28 N. Kaiser

We have studied the $\gamma p \to K^0 \Sigma^+$ reaction in the energy region around the $K^* \Lambda$ and $K^* \Sigma$ thresholds, where the CBELSA/TAPS cross section shows a sudden drop and the differential cross section experiences a…

Nuclear Theory · Physics 2015-06-15 A. Ramos , E. Oset

We develop a model to study the $D^0 \to K^- \pi^+ \eta$ weak decay, starting with the color favored external emission and Cabibbo favored mode at the quark level. A less favored internal emission decay mode is also studied as a source of…

High Energy Physics - Phenomenology · Physics 2021-04-14 Genaro Toledo , Natsumi Ikeno , Eulogio Oset

The s-wave meson-baryon interaction in the $S = -1$ sector is studied by means of coupled-channels, using the lowest-order chiral Lagrangian and the N/D method to implement unitarity. The loops are regularized using dimensional…

Nuclear Theory · Physics 2009-11-07 E. Oset , A. Ramos , C. Bennhold

Based on chiral unitary approach, we construct the realistic KbarN local potential, which is useful for the quantitative calculation of Kbar-nuclei. Since the resonance pole structure of the KbarN system seems important for the Kbar-nuclei…

Nuclear Theory · Physics 2016-06-22 Kenta Miyahara , Tetsuo Hyodo

We investigate pion photoproduction off the proton in a manifestly gauge-invariant chiral unitary extension of chiral perturbation theory. In a first step, we consider meson-baryon scattering taking into account all next-to-leading order…

Nuclear Theory · Physics 2013-05-30 Maxim Mai , Peter C. Bruns , Ulf-G. Meissner

A recently developed non-perturbative chiral approach to dynamically generate the (3/2^-) baryon resonances has been extended to investigate the radiative decays Lambda^*(1520) --> gamma Lambda(1116) and Lambda^*(1520) --> gamma…

Nuclear Theory · Physics 2008-11-26 M. Doring , E. Oset , Sourav Sarkar

Using the CLAS detector system in Hall B at Jefferson Lab, we have done a high statistics measurement of the photoproduction of K+ Lambda(1405) using a proton target. The reconstructed invariant mass seen in the various Sigma pi decay modes…

Nuclear Experiment · Physics 2014-11-20 Kei Moriya , Reinhard Schumacher

Electromagnetic mean squared radii of Lambda(1405) are evaluated in chiral unitary approach. In this approach we regard Lambda(1405) as dynamically generated resonances in the octet meson and octet baryon scattering, and also as KbarN bound…

Nuclear Theory · Physics 2009-01-14 Takayasu Sekihara , Tetsuo Hyodo , Daisuke Jido

The internal structure of the resonant Lambda(1405) state is investigated based on meson-baryon coupled-channels chiral dynamics, by evaluating density distributions obtained from the form factors of the Lambda(1405) state. The form factors…

Nuclear Theory · Physics 2015-05-27 Takayasu Sekihara , Tetsuo Hyodo , Daisuke Jido

In this work, we perform a \textit{toy-model} analysis for the unpolarized photo- and electroproduction of $\Lambda(1405)\equiv\Lambda^*$ via $\gamma^{(*)}p\to K^+\pi^+\Sigma^-$ by employing the effective Lagrangian approach at the tree…

High Energy Physics - Phenomenology · Physics 2017-11-22 Seung-il Nam

The s-wave meson-nucleon interaction in the $S = -1$ sector is studied by means of coupled-channel Lippmann Schwinger equations, using the lowest order chiral Lagrangian and a cut off to regularize the loop integrals. The method reproduces…

Nuclear Theory · Physics 2009-10-30 E. Oset , A. Ramos

In this work, the production mechanisms of the hyperon resonances $\Lambda(1405)$ and $\Lambda(1520)$ in the $\pi^- p$ scattering are investigated within an effective Lagrangian approach incorporating Regge trajectories. By including…

Nuclear Theory · Physics 2026-02-19 Yuan Gao , Xiao-Yun Wang , Xiang Liu

We develop a novel model utilizing the forward $K^*$ production reaction off the nucleon, $\pi N \to K^* MB$, induced by a high-momentum $\pi$ beam, as a tool to study low-lying $Y^*$ resonances below and just above the $\bar{K}N$…

High Energy Physics - Phenomenology · Physics 2026-05-26 H. Kamano , T. -S. H. Lee

S-wave $K^-p$ scattering into various channels near threshold are analyzed in heavy-baryon chiral perturbation theory with $\Lambda (1405)$ introduced as an independent field. This is the approach that predicted the critical density…

High Energy Physics - Phenomenology · Physics 2015-06-25 Chang-Hwan Lee , Dong-Pil Min , Mannque Rho

The Crystal Ball Collaboration has recently reported the differential cross sections and $\Lambda$ polarization for the reaction $K^-p\rightarrow \pi^0\Lambda$ using an incident $K^-$ beam with momenta between 514 and 750 MeV/$c$. We make a…

Nuclear Theory · Physics 2011-09-07 Puze Gao , B. S. Zou , A. Sibirtsev

We present a unified picture which studies simultaneously the gamma gamma--> pi^+ pi^-, pi^0 pi^0,K^+ K^-, K^0 bar{K}^0, pi^0 eta reactions up to about sqrt(s)=1.4 GeV reproducing the experimental cross sections. The present work implements…

High Energy Physics - Phenomenology · Physics 2010-11-15 J. A. Oller , E. Oset

We study the Lambda_c decay process to pi^+ and the meson-baryon final state for the analysis of Lambda resonances. Considering the Cabibbo-Kobayashi-Maskawa matrix, color suppression, diquark correlation and the kinematical condition, we…

Nuclear Theory · Physics 2015-12-09 Kenta Miyahara , Tetsuo Hyodo , Eulogio Oset