相关论文: Light Baryon Resonances: Restrictions and Perspect…
Using the general connection between the upper limit on the neutrino mass and the upper limits on certain types of non-Standard Model interaction that can generate loop corrections to the neutrino mass, we derive constraints on some…
The bounds on neutrino masses and mixing that follows from the data on light element abundances, large scale structure formation, and angular fluctuations of cosmic microwave background radiation are analyzed. The role of neutrino…
An analysis is presented of the ground state baryon's (N and \Delta) masses and axial couplings in the combined 1/Nc and chiral expansions. Renormalization and alternative power counting schemes are discussed to one loop (NNLO). An…
We show that the existence of massive neutron stars and asymptotic freedom of QCD place robust upper bounds on the lowest sound speed of the ultra-dense matter unattainable in neutron stars. Centered on worst-case scenarios, our limits are…
We review ideas and speculations concerning possible bound states or resonances of the nucleon--antinucleon system.
The present status in the field of strange mesons in nuclei and neutron stars is reviewed. In particular, the $\bar K N$ interaction, that is governed by the presence of the $\Lambda(1405)$, is analyzed and the formation of the $\bar K NN$…
The likely presence of $\Lambda$ baryons in dense hadronic matter tends to soften the equation of state to an extend that the observed heaviest neutron stars are difficult to explain. We analyze this "hyperon problem" with a…
We discuss properties of baryon resonances belonging to the Nucleon, Delta, Sigma, Lambda, Xi and Omega families in a collective string-like model for the nucleon, in which the radial excitations are interpreted as rotations and vibrations…
We have calculated the mass spectra of nucleon and delta hybrid baryons with both positive-parity and negative-parity by using the method of QCD sum rules. We predicte that the lowest-lying hybrid baryons are the negative-parity $N_{1/2^-}$…
The presence of additional neutrino states with masses in the GeV range is allowed by electro-weak precision observables. However, these additional states can lead to lepton number violating interactions which potentially can wash out…
We investigate the effect of $\Delta$ baryons on the radial oscillations of neutron and hyperon stars, employing a density-dependent relativistic mean-field model. The spin-$3/2$ baryons are described by the Rarita-Schwinger Lagrangian…
This talk focuses on a recent work aiming at determining the composition of certain $N^*$ and $\Delta$ resonances, i.e. whether they are compact states formed directly by quarks and gluons, or composite generated from the meson-baryon…
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…
A nearest-neighbor analysis of light flavor baryon mass spectra reveals striking degeneracy patterns- narrow mass bands populated by series of parity twins of steadily increasing spins. Each series terminates by an unpaired resonance of the…
Latest results from a study of baryon ground and resonant states within relativistic constituent quark models are reported. After recalling some typical spectral properties, the description of ground states, especially with regard to the…
The properties of ground-state baryons of light-quarks are investigated in U(12)-classification scheme of hadrons, recently proposed by us. In U(12), in addition to the ordinary 56 of SU(6)SF, the existence of the extra 56 with…
This work aims at determining the composition of certain $N^*$ and $\Delta$ resonances, i.e. whether they are compact states formed directly by quarks and gluons, or hadronic molecules generated from the meson-baryon interaction. The…
We study the effects of light gluinos with mass below about 1 GeV on the nucleon parton densities and the running of alpha_(S). It is shown that from the available high-statistics DIS data no lower bound on the gluino mass can be derived.…
We investigate how current and proposed observations of neutron stars can lead to an understanding of the state of their interiors and the key unknowns: the typical neutron star radius and the neutron star maximum mass. A theoretical…
In this article I review the constraints on neutrino mass and mixing coming from type-II supernovae. The bounds obtained on these parameters from shock reheating, r-process nucleosynthesis and from SN1987A are discussed. Given the current…