It is well known that the Zee model induces small neutrino masses by radiative corrections, where the bi-maximal flavor mixing is possible. We analyze the cosmological condition in order for the baryon asymmetry generated in the early universe not to be washed out in the Zee model. Since the lepton number is violated explicitly in the Zee model, the baryon asymmetry might be washed out through ...

In unification models based on SU(15) or SU(16), baryon number is part of the gauge symmetry, broken spontaneously. In such models, we discuss various scenarios of important baryon number violating processes like proton decay and neutron-antineutron oscillation. Our analysis depends on the effective operator method, and covers many variations of symmetry breaking, including different intermedia...

Abstract The observational relation between the density of baryon and dark matter in the Universe, ΩDM/ΩB ≃ 5, is one of the most difficult problems to solve in modern cosmology. We discuss a scenario that explains this relation by combining the asymmetric dark matter scenario and the spontaneous baryogenesis associated with the flat direction in the supersymmetric standard model. A part of bar...

We develop perturbative QCD factorization theorems for the exclusive semileptonic heavy baryon decay Λb → plν̄, in which the relevant hadronic form factor is expressed as the convolution of a hard subamplitude with the Λb baryon wave function and the proton wave function. The specific evolution scale for the proton wave function, determined from the best fit to the data of the proton form factor...

We compute as a function of rapidity y the baryon number carried by quarks and antiquarks with pT > p0 ≈ 2 GeV produced in Pb+Pb collisions at TeV energies. The computation is carried out in lowest order QCD perturbation theory using structure functions compatible with HERA results. At p0 = 2 GeV the initial gluon density is both transversally saturated and thermalised in the sense that the ene...

We show that a class of inhomogeneous big bang nucleosynthesis models exist which yield light-element abundances in agreement with observational constraints for baryon-tophoton ratios significantly smaller than those inferred from standard homogeneous big bang nucleosynthesis (HBBN). These inhomogeneous nucleosynthesis models are characterized by a bimodal distribution of baryons in which some ...

A profound understanding of the nature of meson and baryon resonances is one of the outstanding issues of QCD. The discovery of meson and baryon resonance states with exotic quantum numbers turns this into a burning question deserving prime attention. The goal is to establish a systematic approach which is capable of describing and predicting the resonance spectrum of QCD quantitatively. In thi...

We have analyzed the properties of a sample of 33 groups and clusters of galaxies for which both optical and X-ray data were available in the literature. This sample was built to examine the baryon content and to check for trends over a decade in temperature down to 1 keV. We examine the relative contribution of galaxies and ICM to baryons in clusters through the gas-to-stellar mass ratio (Mgas...

The chiral expansion of the one-loop corrections to baryon masses is examined in a generic meson-cloud model with meson-baryon form factors. For pion loops, the expansion is rapidly convergent and at fourth order inmπ accurately reproduces the full integral. In contrast, the expansion is found to converge very slowly for kaon loops, raising questions about the usefulness of chiral expansions fo...

We consider the production of baryon number from collapsing domain walls, and in particular examine the magnitude of CP violation which is required in such schemes. Taking the conventional solution to the domain wall problem in the Nextto-Minimal Supersymmetric Standard Model as an example, we show that the observed baryon assymmetry of the universe may have been generated, even if the initial ...