Search results for "Octet"
showing 10 items of 40 documents
Recent developments in chiral dynamics of hadrons and hadrons in a nuclear medium
2006
In this talk I present recent developments in chiral dynamics of hadrons and hadrons in a medium addressing the following points: interaction of the octet of pseudoscalar mesons with the octet of baryons of the nucleon, showing recent experimental evidence on the existence of two $\Lambda(1405)$ states, the interaction of the octet of pseudoscalar mesons with the decuplet of baryons of the $\Delta$, with particular emphasis on the $\Lambda(1520)$ resonance, dynamically generated by this interaction. Then I review the interaction of kaons in a nuclear medium and briefly discuss the situation around the claims of deeply bound states in nuclei. The large renormalization of the $\Lambda(1520)$ …
Radiative decay into gamma-baryon of dynamically generated resonances from the vector-baryon interaction
2010
We study the radiative decay into gamma and a baryon of the SU(3) octet and decuplet of nine and ten resonances that are dynamically generated from the interaction of vector mesons with baryons of the octet and the decuplet, respectively. We obtain quite different partial decay widths for the various resonances, and for different charge states of the same resonance, suggesting that the experimental investigation of these radiative decays should bring much information on the nature of these resonances. For the case of baryons of the octet we determine the helicity amplitudes and compare them with experimental data when available.
Dynamically generated resonances from the vector octet-baryon decuplet interaction and their radiative decays into γ-baryon decuplet
2009
The dynamically generated resonances from vector meson-baryon decuplet are studied using Lagrangians of the hidden gauge theory for vector interactions. One shows that some of the generated states can be associated with some known baryon resonances in the PDG data, while others are predictions for new states. Furthermore, we calculate the radiative decay widths of these resonances into a photon and a baryon decuplet.
Radiative decay of the
2007
Abstract Electromagnetic properties provide information about the structure of strongly interacting systems and allow for independent tests of hadronic models. The radiative decay of the Δ ∗ ( 1700 ) is studied, which appears dynamically generated in a coupled channel approach from the rescattering of the ( 3 / 2 + ) decuplet of baryons with the ( 0 − ) octet of pseudoscalar mesons. The radiative decay is predicted from the well-known couplings of the photon to the mesons and baryons which constitute this resonance in the dynamical picture.
The baryonic spectrum in a constituent quark model including a three-body force
1992
We analyze, within a non-relativistic quark model, the low energy part of the baryonic spectrum in the octet and decuplet flavour representations. The relevance of a strong Coulomb potential is emphasized in order to explain its general features. The addition of a three-body force allows to solve the ‘Roper puzzle’, giving a consistent explanation to its relative position in the spectrum.
Low-lying resonances from chiral unitary dynamics
2003
Abstract The s-wave meson-baryon interaction is studied using the lowest-order chiral lagrangian in a unitary coupled-channels Bethe-Salpeter equation. The resonances belonging to the low-lying J P = 1 2 − octet, the N (1535), Λ(1620) and Ξ(1620), together with the Λ(1405) singlet, are generated dynamically through multiple meson-baryon scattering. The Λ(1405) appears as a mixture of K N and πΣ quasibond states, while the Λ(1670) is a K Ξ quasibond state. Arguments are given to assigne J P = 1 2 − to the unmeasured spin and parity of the Ξ(1620).
Spin, parity and nature of the Xi(1620) resonance
2002
Using a unitary extension of chiral perturbation theory with a lowest-order s -wave SU(3) chiral Lagrangian we study low-energy meson-baryon scattering in the strangeness S = − 2 sector. A scattering-matrix pole is found around 1605 MeV which corresponds to an s -wave Ξ resonance with J P = 1 / 2 − . We identify this resonance with the Ξ ( 1620 ) state, quoted by the Particle Data Group with I = 1 / 2 but with unknown spin and parity. The addition of the S = − 2 state to the recently computed Λ ( 1670 ) , Σ ( 1620 ) , and N ( 1535 ) states completes the octet of J P = 1 / 2 − resonances dynamically generated in this chiral unitary approach.
Baryonic resonances from baryon decuplet-meson octet interaction
2004
We study $S$-wave interactions of the baryon decuplet with the octet of pseudoscalar mesons using the lowest order chiral Lagrangian. In the S=1 sector, we find an attractive interaction in the $\Delta K$ channel with I=1 while it is repulsive for I=2. The attractive interaction leads to a pole in the second Riemann sheet of the complex plane and is manifested as a large strength in the scattering amplitude close to the $\Delta K$ threshold, which is not the case for I=2. We use the unitarized coupled channel approach to also investigate all the other possible values of strangeness and isospin. We find two bound states in the SU(3) limit corresponding to the octet and decuplet representatio…
Production of a forward J/Psi and a backward jet at the LHC
2015
We study the production of a forward $J/\psi$ meson and a backward jet with a large rapidity separation at the LHC using the BFKL formalism. We compare the predictions given by the Non Relativistic QCD (NRQCD) approach to charmonium prediction and by the Color Evaporation Model. In NRQCD, we find that the $^3 S_1^{\, 8}$ part of the onium wavefunction is completely dominating the process. NRQCD and the color evaporation model give similar results, although a discrepancy seems to appear as the value of the transverse momenta of the charmonium and of the jet decrease.
Radiative decays of the Δ*(1700) and the Λ*(1520)
2008
Electromagnetic properties provide information about the structure of strongly interacting systems and allow for independent tests of hadronic models. The radiative decays of the Δ*(1700) and Λ*(1520) are studied, which appear dynamically generated in a coupled channel approach from the rescattering of the (3/2+) decuplet of baryons with the (0−) octet of pseudoscalar mesons. The radiative decays are predicted from the well-known couplings of the photon to the mesons and hadrons which constitute these resonances in the dynamical picture.