Related papers: Pion-assisted Nucleon-Delta and Delta-Delta dibary…
We use a consistent SU(6) extension of the meson-baryon chiral Lagrangian within a coupled channel unitary approach in order to calculate the T-matrix for meson-baryon scattering in s-wave. The building blocks of the scheme are the pion and…
The so far only known charmed non-strange scalar meson is dubbed as $D_0^*(2400)$ in the Review of Particle Physics. We show, within the framework of unitarized chiral perturbation theory, that there are in fact two $(I=1/2, J^P=0^+)$ poles…
Delta I=3/2, K to Pi Pi matrix elements are calculated on 68 configurations of quenched 24^3 x 64 lattices using the DBW2 action, and domain wall fermions with L_s=16. The lattice spacing is a^(-1)=1.3 GeV, corresponding to a physical…
The structure of $\Delta\Delta$ dibaryon is studied in the extended chiral SU(3) quark model in which vector meson exchanges are included. The effect from the vector meson fields is very similar to that from the one-gluon exchange (OGE)…
Using the dcQMD transport model, the isoscalar and isovector in-medium potentials of the $\Delta$(1232) baryon are studied and information regarding their effective strength is obtained from a comparison to experimental pion production data…
We report novel theoretical results for the $\gamma^{(*)} + N(940)\frac{1}{2}^+ \to \Delta(1700)\frac{3}{2}^{-}$ transition, utilizing a symmetry-preserving treatment of a vector$\,\otimes\,$vector contact interaction (SCI) within the…
The deuteron spectrum in n+p -> d+pi+pi at k_n = 1.88 GeV/c and theta_d = 0 deg is explained by considering a Delta-Delta excitation as the reaction mechanism for the 2pi production. We study the influence of intermediate Delta-Delta and…
To determine nonspherical angular momentum amplitudes in hadrons at long ranges (low Q^2), data were taken for the p(\vec{e},e'p)\pi^0 reaction in the Delta region at Q^2=0.060 (GeV/c)^2 utilizing the magnetic spectrometers of the A1…
A model for the gamma p ----> pion+ pion- p reaction developed earlier is extended to account for all isospin channels. The model includes N, Delta(1232), N^*(1440) and N^*(1520) as intermediate baryonic states and the rho-meson as an…
We study the pionic decay of a possible dibaryon d' --> N N \pi in the microscopic quark shell model. The initial d' dibaryon wave function (J^P=0^-, T=0) consists of one 1\hbar\omega six-quark shell-model s^5p[51]_X configuration. The most…
The lower excitation spectrum of the nucleon and $\Delta$ is calculated in a relativistic chiral quark model. Contributions of the second order self-energy and exchange diagrams due-to pion fields to the mass spectrum of the SU(2) baryons…
A series of publications of the WASA collaboration culminates in a recent paper of Pricking, Bashkanov and Clement [1] claiming a dibaryon resonance at 2370 MeV. However, as explained here, there are logical flaws in this result. A natural…
It is seen by a coupled-channel calculation that in the two-baryon N-Delta or Delta-Delta system the width of the state is greatly diminished due to the relative kinetic energy of the two baryons, since the internal energy of the particles,…
In this work, the electromagnetic and gravitational form factors of $\Delta$ isobars, as well as the electromagnetic $N-\Delta$ transition form factors are studied systematically and continuously using a covariant quark-diquark approach…
We calculate the electromagnetic, axial and pseudo-scalar form factors of the Nucleon to $\Delta(1232)$ transition using two dynamical light degenerate quarks and a dynamical strange quark simulated with the domain wall fermion action.…
We extend the relativistic mean-field models with hadron masses and meson-baryon coupling constants dependent on the scalar $\sigma$ field, studied previously to incorporate $\Delta(1232)$ baryons. Available empirical information is…
Phase shifts and inelasticity parameters for $NN$ scattering in the partial-wave channels ${}^3S_1$--${}^3D_1$ and ${}^1S_0$ at energies $T_{\rm lab}$ from zero to about 1 GeV are described within a unified $NN$ potential model assuming the…
The pion-nucleon interaction in the P33 partial wave is assumed to proceed simultaneously through the excitation of the Delta-isobar and through a phenomenologically introduced non-resonant background potential. The introduction of the…
With an effective Lagrangian approach, we analyze several NN \to NN\pi\pi channels by including various resonances with mass up to 1.72 GeV. For the channels with the pion pair of isospin zero, we confirm the dominance of N*(1440)\to…
We present results on the mass of the nucleon and the $\Delta$ using two dynamical degenerate twisted mass quarks. The evaluation is performed at four quark masses corresponding to a pion mass in the range of 690-300 MeV on lattices of size…