Related papers: Nucleon matrix elements and baryon masses in the D…
The electromagnetic form factors are the most fundamental quantities to describe the internal structure of the nucleon and are related to the charge radii of the baryons. We have calculated the charge radii of octet baryons in the framework…
We analyze the octet baryon masses and the pion--nucleon $\sigma$--term in the framework of heavy baryon chiral perturbation theory. In contrast to previous investigations, we include {\it all} terms up-to-and-including quadratic order in…
The axial charge g_A is calculated in the epsilon regime of Heavy Baryon Chiral Perturbation Theory to order epsilon^3. To perform this calculation, we develop a technique to compute baryon properties in the epsilon regime of Chiral…
We calculate the complete $T$ matrices with decuplet contributions for pion-nucleon scattering to order $\mathcal{O}(\epsilon^3)$ in heavy baryon SU(3) chiral perturbation theory. The baryon mass in the chiral limit $M_0$ and the low-energy…
We calculate the nucleon mass within a manifestly relativistic formulation of baryon chiral perturbation theory (BChPT), extending the framework to leading two-loop order ($\mathcal{O}(p^5)$). By employing dimensional counting analysis and…
The electromagnetic form factors are the most fundamental quantities to describe the internal structure of the nucleon and the shape of a spatially extended particle is determined by its {\it intrinsic} quadrupole moment which is first…
The mass spectra of nucleon resonances with spin 1/2, 3/2, and 5/2 are systematically studied in the constituent quark model with meson-quark coupling, which is inspired by the spontaneous breaking of chiral symmetry of QCD. The meson-quark…
We calculate the baryon octet masses to fourth order in chiral perturbation theory employing dimensional and cut-off regularization. We analyze the pion and kaon mass dependences of the baryon masses based on the MILC data. We show that…
We report on recent results of the QCDSF/UKQCD Collaboration on investigations of baryon structure using configurations generated with N_f=2+1 dynamical flavours of O(a) improved Wilson fermions. With the strange quark mass as an additional…
We discuss recent calculations of the mass spectrum, electromagnetic and strong couplings of baryon resonances. The calculations are done in a collective constituent model for the nucleon, in which the resonances are interpreted as…
We discuss the strong coupling of heavy mesons to a pion g, in the heavy quark limit. This quantity is quite remarkable since its values as estimated by different methods (various quark models and the QCD sum rules), are surprisingly…
We perform a chiral extrapolation of the baryon octet and decuplet masses in a relativistic formulation of chiral perturbation theory. A partial summation is assumed as implied by the use of physical baryon and meson masses in the one-loop…
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…
The dark matter in the galaxy cluster Abell 1689 is modelled as an isothermal sphere of neutrinos. New data on the $2d$ mass density allow an accurate description of its core and halo. The model has no "missing baryon problem" and beyond…
We present a study of axial charges of baryon ground and resonant states with relativistic constituent quark models. In particular, the axial charges of octet and decuplet $N$, $\Sigma$, $\Xi$, $\Delta$, $\Sigma^*$, and $\Xi^*$ baryons are…
Understanding the novel QCD phenomenon under high external magnetic fields of hot and dense medium help us to develop a better understanding of the underlying quark dynamics of baryons. Using a hybrid approach based on the effective field…
We present a detailed analysis of statistical and systematic errors in the calculation of matrix elements of iso-vector scalar, axial and tensor charges between a neutron and a proton state. These analyses are being done on dynamical…
We compute the quark-mass dependence of the baryon octet and decuplet masses within the $\chi$-MS scheme at the one-loop level. The results are confronted with recent lattice QCD simulations of the MILC collaboration. A fair reproduction of…
We present an updated analysis of the quark mass dependence of the nucleon mass and nucleon axial-vector coupling g_A, comparing different formulations of SU(2) Baryon Chiral Effective Field Theory, with and without explicit delta (1232)…
The current status of calculations of simple nucleon structure observables is reviewed, with a focus on the axial charge. A major challenge is the combination of an exponentially decaying signal-to-noise ratio and the need for large…