Baryon Fluctuations in Extended Linear Sigma Model

Pion - nucleon scattering and the nucleon sigma term in an extended linear sigma model

A modified linear sigma model that allows for g A = 1.26 by addition of vector and pseudovector πN coupling terms was discussed by Bjorken and Nauenberg and by Lee. In this extended linear sigma model the elastic πN scattering amplitudes satisfy the relevant chiral low-energy theorems, such as the Weinberg-Tomozawa relation for the isovector πN scattering length and in some cases Adler's " cons...

× U ( 3 ) Linear Sigma Model

Excited scalar and pseudoscalar mesons in the extended linear sigma model

We present an in-depth study of masses and decays of excited scalar and pseudoscalar [Formula: see text] states in the Extended Linear Sigma Model (eLSM). The model also contains ground-state scalar, pseudoscalar, vector and axial-vector mesons. The main objective is to study the consequences of the hypothesis that the [Formula: see text] resonance, observed a decade ago by the BES Collaboratio...

Spectral-fluctuations test of the quark-model baryon spectrum.

We study the low-lying baryon spectrum (up to 2.2 GeV) provided by experiments and different quark models using statistical tools which allow us to postulate the existence of missing levels in spectra. We confirm that the experimental spectrum is compatible with random matrix theory, the paradigmatic model of quantum chaos, and we find that the quark models are more similar to a Poisson distrib...

Stochastic Isocurvature Baryon Fluctuations, Baryon Diffusion, and Primordial Nucleosynthesis

We examine effects on primordial nucleosynthesis from a truly random spatial distribution in the baryon-to-photon ratio (η). We generate stochastic fluctuation spectra characterized by different spectral indices and root-mean-square fluctuation amplitudes. For the first time we explicitly calculate the effects of baryon diffusion on the nucleosynthesis yields of such stochastic fluctuations. We...