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Related papers: Evidence for two Lambda(1405) resonance states

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We study the reactions $J/\psi\to\bar{\Lambda}K^-p$ and $J/\psi\to\bar{\Lambda}\pi^+\pi^-\Lambda$ with a unitary chiral approach. We predict the ratio of the invariant mass distributions of these two reactions at the $\Lambda(1520)$ peak…

High Energy Physics - Phenomenology · Physics 2008-12-18 L. S. Geng , E. Oset , B. S. Zou

In this report, we present our recent studies on the Lambda(1405,1/2-)=Lambda* photoproduction via the gamma p -> K+ pi Sigma scattering process, employing a coupled-channel formalism, i.e., the chiral unitary model, which respects chiral…

High Energy Physics - Phenomenology · Physics 2009-01-28 Seung-il Nam , Daisuke Jido

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 study the decay $\Lambda_c^+ \to \Lambda \pi^+ \pi^+ \pi^-$, focusing on the production of the $\Sigma^*(1430)$ resonance observed by the Belle Collaboration. Interpreted as a dynamically generated state from meson-baryon interactions in…

High Energy Physics - Phenomenology · Physics 2025-05-29 Yi-Yao Li , Jing Song , Eulogio Oset , Wei-Hong Liang , Raquel Molina

The $\Lambda p \to \Lambda p \pi^0$ reaction near threshold is studied within an effective Lagrangian method. The production process is described by single-pion and single-kaon exchange. In addition to the role played by the…

Nuclear Theory · Physics 2014-11-19 Ju-Jun Xie , Jia-Jun Wu , Bing-Song Zou

We study the structure of the baryon resonances $\Lambda(1405)$ and $\bar\Lambda(1405)$ in $J/\psi$ four body decays $J/\psi\to \Sigma\bar \Sigma \pi\pi$ in the framework of a coupled channel chiral unitary approach. With still sufficient…

Nuclear Theory · Physics 2009-11-10 Chiangbing Li , E. Oset

The pp -> p K+ Y0 reaction has been studied for hyperon masses m(Y0)<1540 MeV/c2 at COSY-Juelich by using a 3.65 GeV/c circulating proton beam incident on an internal hydrogen target. Final states comprising two protons, one positively…

The reaction gamma + p -> K+ + Sigma + pi was used to determine the invariant mass distributions or "line shapes" of the Sigma+ pi-, Sigma- pi+ and Sigma0 pi0 final states, from threshold at 1328 MeV/c^2 through the mass range of the…

Nuclear Experiment · Physics 2013-03-27 Kei Moriya , Reinhard Schumacher

In the QCD sum rule approach we predict the $\Lambda$ (1405) mass by choosing the $\pi^0\Sigma^0$ multiquark interpolating field. It is found that the mass is about 1.419 GeV from $\Pi_1 (q^2)$ sum rule which is more reliable than $\Pi_q…

Nuclear Theory · Physics 2009-10-30 Seungho Choe

We present an analysis of the Lambda(1405) resonance produced in the reaction p+p->Sigma^{pm}+pi^{mp}+K+p at 3.5 GeV kinetic beam energy measured with HADES at GSI. The two charged decay channels Lambda(1405) -> Sigma^{\pm}+pi^{\mp} have…

The $\gamma p \to K^+ \pi^0 \Lambda$ and $\gamma p \to K^+ \pi \Sigma $ reactions are studied in the kinematic region where the $\pi^0 \Lambda$(1116) and $\pi\Sigma$(1192) pairs originate dominantly from the decay of the $\Sigma$(1385) and…

Nuclear Theory · Physics 2010-12-16 Madeleine Soyeur , Matthias F. M. Lutz

We study the $\bar K p \to Y K\bar K \pi$ reactions with $\bar K = \bar K^0, K^-$ and $Y=\Sigma^0, \Sigma^+, \Lambda$, in the region of $K\bar K \pi$ invariant masses of $1200-1550$ MeV. The strong coupling of the $f_1(1285)$ resonance to…

High Energy Physics - Phenomenology · Physics 2020-06-24 Wei-Hong Liang , E. Oset

We have studied the strangeness changing antineutrino induced reactions $\bar{\nu}_{l} p \rightarrow l^+ \phi B $, with $\phi B = K^-p$, $\bar{K}^0n$, $\pi^0\Lambda$, $\pi^0\Sigma^0$, $\eta\Lambda$, $\eta\Sigma^0$, $\pi^+\Sigma^-$,…

High Energy Physics - Phenomenology · Physics 2015-04-16 Xiulei Ren , E. Oset , L. Alvarez-Ruso , M. J. Vicente Vacas

We study the pp -> p Lambda K+ and pp -> p Sigma0 K+ reactions near threshold by using a chiral unitary approach. We consider the single-pion and single-kaon exchange as well as the final state interactions of nucleon-hyperon, K-hyperon and…

Nuclear Theory · Physics 2011-08-23 Hua-Xing Chen , Ju-Jun Xie , E. Oset

Recent experimental results for the reaction \gamma + p \to K^+ + \Sigma + \pi\ from CLAS at Jefferson Lab are discussed. It was found that the mass distributions or "line shapes" of the three charge combinations \Sigma^+ \pi^-, \Sigma^0…

Nuclear Experiment · Physics 2015-06-15 Reinhard A. Schumacher , Kei Moriya

We study the gamma p ---> K^+ Lambda(1405) reaction at energies close to threshold using a chiral unitary model where the resonance is generated dynamically from K^-p interaction with other channels constructed from the octets of baryons…

Nuclear Theory · Physics 2009-10-31 J. C. Nacher , E. Oset , H. Toki , A. Ramos

The Sigma-pi invariant-mass spectra in the resonant capture of K- at rest in 4He, 3He and d are calculated by a coupled-channel procedure for a K-p quasi-bound state of an arbitrary chosen mass (M) and width (Gamma). A chi2 analysis of old…

Nuclear Theory · Physics 2010-03-02 Jafar Esmaili , Yoshinori Akaishi , Toshimitsu Yamazaki

Using a chiral unitary approach for meson-baryon scattering in the strangeness zero sector, where the $N^*(1535)$ resonance is dynamically generated, we study the reactions $\gamma p \to \pi^0 \eta p$ and $\gamma p \to \pi^0 K^0 \Sigma^+$…

Nuclear Theory · Physics 2009-11-11 M. Doring , E. Oset , D. Strottman

We present a formalism for the low-energy analysis of the $\gamma p\rightarrow K^{+}\pi\Sigma$ photoproduction reaction in the $\Lambda^{\ast}(1405)$ resonance region. In particular, the constraints arising from unitarity, gauge invariance…

Nuclear Theory · Physics 2022-06-20 Peter C. Bruns

The processes of $K^-p \to \pi^0 \pi^0 \Sigma^0$ and $K^- p \to \pi^0 \Lambda(1405)$ are studied within the effective Lagrangian approach. In addition to the ``background" contribution from the $u$-channel nucleon pole term, contribution…

High Energy Physics - Phenomenology · Physics 2026-01-08 Xing-Yi Ji , Si-Wei Liu , Wen-Tao Lyu , De-Min Li , En Wang , Ju-Jun Xie