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

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We have calculated the femtoscopic correlation functions of meson-baryon pairs in the strangeness $S=-1$ sector, employing a unitarized chiral interaction model up to next-to-leading order. We will show preliminary results for the…

High Energy Physics - Phenomenology · Physics 2024-10-29 Pablo Encarnacion , Albert Feijoo , Angels Ramos

We present a gauge invariant approach to photoproduction of mesons on nucleons within a chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the chiral effective Lagrangian and iterated in a…

Nuclear Theory · Physics 2008-11-26 B. Borasoy , P. C. Bruns , Ulf-G. Meißner , R. Nißler

We perform a theoretical study of the weak decay $\Lambda_c^+ \rightarrow \bar{K}^0 \eta p$ using a coupled-channel chiral unitary approach that incorporates both pseudoscalar-baryon and vector-baryon interactions. Our framework includes…

High Energy Physics - Phenomenology · Physics 2025-07-28 Jing Song , Melahat Bayar , Yi-Yao Li , Eulogio Oset

The reactions $\gamma p \rightarrow K^{+}\Sigma^{\pm}\pi^{\mp}$ were studied with the SAPHIR detector using a tagged photon beam at the electron stretcher facility ELSA in Bonn. The decays $\Sigma^{-} \rightarrow n\pi^{-}$ and $\Sigma^{+}…

We use a nonperturbative approach which combines coupled channel Lippmann Schwinger equations with meson-meson potentials provided by the lowest order chiral Lagrangians. By means of one parameter, a cut off in the momentum of the loop…

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

We study the strong interaction S-wave \Lambda\pi phase shift in the region of the \Xi mass in the framework of a relativistic chiral unitary approach based on coupled channels. All parameters have been previously determined in a fit to…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ulf-G. Meißner , José Antonio Oller

We make a theoretical study of the charge and forward-backward pion asymmetries in the e+e- --> pi+ pi- gamma process on and off the phi resonance energy. These observables are rather sensitive to the inner details of the theoretical models…

High Energy Physics - Phenomenology · Physics 2010-02-03 L. Roca , E. Oset

We investigate the $K^- p \to \gamma \Sigma$ reaction using an effective Lagrangian approach within an isobar model framework. The model includes contributions from $s$-channel hyperon and hyperon resonance, $t$-channel $K$ and $K^*$,…

High Energy Physics - Phenomenology · Physics 2025-11-18 Yi Pan , Bo-Chao Liu

We perform a theoretical study based on dispersion relations of the reaction \gamma\gamma\to \pi^0\pi^0 emphasizing the low energy region. We discuss how the f_0(980) signal emerges in \gamma\gamma\to \pi\pi within the dispersive approach…

High Energy Physics - Phenomenology · Physics 2008-10-08 J. A. Oller , L. Roca

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

This study presents a tree-level calculation of the scattering amplitude for the $lp\to lp\gamma$ (with a hard photon) process within the framework of Chiral Perturbation Theory. Our calculations, based on the $O(p^2)$ and $O(p^3)$…

High Energy Physics - Phenomenology · Physics 2026-02-13 Xu Wang , Kai-Ge Kang , Zhiguang Xiao , Han-Qing Zheng

The pi0 pi0 mass spectra and angular distributions around KKbar -threshold and at 1.5 GeV in ppbar (at rest) --> 3 pi0 in the Crystal Barrel experiment are reanalyzed by applying the new method, which is consistent with unitarity of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Muneyuki Ishida , Toshihiko Komada , Shin Ishida , Taku Ishida , Kunio Takamatsu , Tsuneaki Tsuru

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

The meson meson interaction in the scalar isoscalar channel at finite baryonic density is studied in the framework of a chiral unitary approach which generates the f0 and sigma resonances and reproduces well the meson meson phase shifts in…

Nuclear Theory · Physics 2007-05-23 M. J. Vicente Vacas , E. Oset

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 2015-03-17 Takayasu Sekihara , Tetsuo Hyodo , Daisuke Jido

In these lectures I make an introduction to chiral unitary theory applied to the meson baryon interaction and show how several well known resonances are dynamically generated, and others are predicted. Two very recent experiments are…

Nuclear Theory · Physics 2011-02-09 E. Oset , D. Cabrera , V. K. Magas , L. Roca , S. Sarkar , M. J. Vicente Vacas , A. Ramos

A coupled-channel (CC) approach has been developed to investigate kaon photoproduction on the nucleon. In addition to direct K+ Lambda production, our CC approach accounts for strangeness production including K+ Lambda final state…

Nuclear Theory · Physics 2009-11-07 Wen-Tai Chiang , F. Tabakin , T. -S. H. Lee , B. Saghai

The reactions gamma p -> K+ Lambda and gamma p -> K* Lambda are analyzed within perturbative QCD, allowing for diquarks as quasi-elementary constituents of baryons. The diquark-model parameters and the quark-diquark distribution amplitudes…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. Kroll , M. Schuermann , K. Passek , W. Schweiger

The $s-$wave meson-baryon scattering is analyzed for the isospin-strangeness $I=1/2, S=0$ and $I=0,S=-1$ sectors, in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry. For both sectors, four channels have been…

Nuclear Theory · Physics 2017-08-23 J. Nieves , C. Garcia-Recio , E. Ruiz Arriola , M. J. Vicente Vacas

We extend our recent non-perturbative chiral SU(3) coupled channel approach to pion- and photon-induced $\eta$- and $K$-meson production off protons by including all strong and electromagnetic p-wave multipoles. We identify the p-wave…

Nuclear Theory · Physics 2009-10-31 J. Caro Ramon , N. Kaiser , S. Wetzel , W. Weise