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Related papers: Effective model for in-medium $\bar{K}N$ interacti…

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We report on recent nonperturbative techniques that combine the information of chiral Lagrangians (with and without resonances) with unitarity in coupled channels and other requirements of the S-matrix theory of the strong interactions. As…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. A. Oller , E. Oset , A. Ramos

We develop a coupled channel unitary approach describing the behavior at higher energies of systems whose low-energy dynamics is given by effective O(p^2) and O(p^4) chiral Lagrangians. Our free parameters are those of the O(p^4)…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. Oller , E. Oset , J. R. Pelaez

In an effective Lagrangian model employing the K-matrix approximation we extract nucleon resonance parameters. To this end we analyze simultaneously all available data for reactions involving the final states $\pi N$, $\pi\pi N$, $\eta N$…

Nuclear Theory · Physics 2008-11-26 T. Feuster , U. Mosel

The s-wave meson-baryon interaction is studied using the lowest-order chiral Lagrangian in a unitary coupled-channels Bethe-Salpeter equation. In the strangeness $S=-1$ sector the low-energy $K^- p$ dynamics leads to the dynamical…

Nuclear Theory · Physics 2017-08-23 A. Ramos , A. Parreno , J. C. Nacher , E. Oset , C. Bennhold

We investigate the elastic $\pi N$ scattering for the $I=3/2$ channel dominated by the $\Delta(1232)$ resonance at finite baryon density $\rho_B$ for the symmetric nuclear matter, employing the effective Lagrangian approach at the…

Nuclear Theory · Physics 2023-02-22 Hyeon-dong Han , Parada T. P. Hutauruk , Seung-il Nam

The s-wave isoscalar amplitude for pion-pion scattering in a nuclear medium is evaluated using a nonperturbative unitary coupled channels method and the standard chiral Lagrangians. The method has proved successful to describe the pion-pion…

Nuclear Theory · Physics 2008-11-26 H. C. Chiang , E. Oset , M. J. Vicente Vacas

The $\Lambda(1405)$ resonance production reaction is investigated within the framework of the coupled-channels Alt-Grassberger-Sandhas (AGS) equations. We perform full three-body calculations for the $\bar{K}NN-\pi YN$ amplitudes on the…

Nuclear Theory · Physics 2016-03-08 Shota Ohnishi , Yoichi Ikeda , Tetsuo Hyodo , Wolfram Weise

We investigate the structure of the Lambda(1405) resonance and Kbar N phenomenology in the perspective of chiral SU(3) dynamics. Utilizing the chiral coupled-channel approach which well describes the Kbar N scattering observable, we perform…

Nuclear Theory · Physics 2009-12-17 Tetsuo Hyodo

The pi N --> KY and KY --> KY reactions are studied using a dynamical coupled-channel model of meson-baryon interactions at energies where the baryon resonances are strongly excited. The channels included are: pi N, K \Lambda, and K\Sigma.…

Nuclear Theory · Physics 2009-11-10 Wen-Tai Chiang , B. Saghai , F. Tabakin , T. -S. H. Lee

We study the S-wave kaon-nucleon interactions for strangeness S=-1 in a novel relativistic chiral unitary approach based on coupled channels. Dispersion relations are used to perform the necessary resummation of the lowest order…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. A. Oller , Ulf-G. Meißner

We derive a single-channel effective Kbar N interaction from chiral SU(3) coupled-channel dynamics, emphasizing the important role of the pi Sigma channel and the structure of the Lambda(1405) resonance. The chiral low energy theorem…

Nuclear Theory · Physics 2009-11-27 Tetsuo Hyodo , Wolfram Weise

The processes involving $K^{-}p, KN, \Sigma\pi, \Lambda\pi,\Sigma\eta, \Lambda\eta$ coupled channels are studied in the nonperturbative chiral approach. An effective potential is constructed using a chiral meson-baryon Lagrangian at lowest…

High Energy Physics - Phenomenology · Physics 2016-09-06 B. Krippa

A new fit of a chirally motivated coupled-channels model for meson-baryon interactions is presented including the recent SIDDHARTA data on the 1s level characteristics of kaonic hydrogen. The kaon-nucleon amplitudes generated by the model…

Nuclear Theory · Physics 2015-06-03 A. Cieply , J. Smejkal

The $\phi$ meson spectrum, which in vacuum is dominated by its coupling to the $\bar{K} K$ system, is modified in nuclear matter. Following a model based on chiral SU(3) dynamics we calculate the $\phi$ meson selfenergy in nuclear matter…

Nuclear Theory · Physics 2011-02-09 D. Cabrera , M. J. Vicente Vacas

The vacuum spectrum of the $\phi$-meson is characterized by its decay into $K{\bar K} $. Modifications of the $K {\bar K}$-loops in baryonic matter change this spectrum. We calculate these in-medium modifications taking both s- and p-wave…

High Energy Physics - Phenomenology · Physics 2009-10-30 F. Klingl , T. Waas , W. Weise

We discuss in this talk aspects of \bar{K}N plus coupled channels dynamics with special emphasis on the \Lambda(1405) resonance and isovector resonances in the same energy region. We comment on several experimental reactions giving rise to…

Nuclear Theory · Physics 2015-06-17 J. A. Oller

We study the consequence of chiral SU(3) symmetry in the kaon-nucleon phenomenology, by deriving the effective single-channel KbarK N potential. It turns out that the pi Sigma interaction is strongly attractive and plays an important role…

Nuclear Theory · Physics 2011-02-18 Tetsuo Hyodo , Wolfram Weise

A comprehensive analysis of all available data on cross sections and spin-dependent observables for the $\gamma p \to K^+ \Sigma^0(1385)$, $\gamma n \to K^+ \Sigma^-(1385)$, and $\pi^+ p \to K^+ \Sigma^+(1385)$ reactions is performed within…

High Energy Physics - Phenomenology · Physics 2025-03-21 Ai-Chao Wang , Neng-Chang Wei , Fei Huang

We investigate the two-body reaction $\pi^- p \to K^{0} \Lambda$ within the effective Lagrangian approach and the isobar model. In addition to the "background" contributions from $t$-channel $K^*$ exchange, $u$-channel $\Sigma(1192)$ and…

Nuclear Theory · Physics 2015-11-30 Cheng-Zu Wu , Qi-Fang Lü , Ju-Jun Xie , Xu-Rong Chen

Chiral effective lagrangians may differ in their prediction of meson-nucleon scattering amplitudes off-meson-mass-shell, but must yield identical S-matrix elements. We argue that the effective meson mass in nuclear matter obtained from…

Nuclear Theory · Physics 2016-09-08 Vesteinn Thorsson , Andreas Wirzba