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Predicting the masses of baryons containing one or two heavy quarks The Feynman-Hellmann theorem and semiempirical mass formulas are used to predict the masses of baryons containing one or two heavy quarks. In particular, the mass of the Λ b is predicted to be 5620 ± 40 MeV, a value consistent with measurements. In a recent paper [1], the Feynman-Hellmann(More)
Radiative energy loss of a highly virtual quark originating from a deep-inelastic electron scattering plays a crucial role in production of leading hadrons off nuclei. The density of energy loss for gluon radiation turns out to be time-and energy–dependent in inclusive hadron production. Important phenomena involved are Sudakov's suppression of no radiation(More)
We discuss a scheme for reconstructing experimentally the diagonal elements of a density matrix representing quantum optical state. Applications to PDC heralded photons, multi-thermal and attenuated coherent states are illustrated and discussed in more detail.
We report on the realisation of a new test of Bell inequalities using the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisations. We discuss the advantages and the possible developments of this configuration. Many experiments have already been devoted to a(More)
The elastic hadronic amplitude is calculated using the nonperturbative light-cone dipole representation for gluon bremsstrahlung. The data for large mass diffraction demand a two-scale structure of light hadrons: the gluon clouds of the valence quarks are much smaller (∼ 0.3 f m) than the hadronic size. The presence of the two scales unavoidably leads to a(More)
There are striking regularities in the masses and mass differences of known hadrons. Some of these regularities can be understood from known general properties of the interactions of quarks without a need to specify the explicit form of the Hamiltonian. The Feynman–Hellmann theorem is one of the tools providing this understanding. If the mass regularities(More)
A new model for the substructure of quarks, lep-tons and weak gauge bosons, is discussed. It is based on three fundamental and absolutely stable spin-1/2 preons. Its preon flavour SU (3) symmetry leads to a prediction of nine quarks, nine leptons and nine heavy vector bosons. One of the quarks has charge −4e/3, and is speculated to be the top quark (whose(More)