The Feynman–Hellmann theorem is used to show that vector meson energy eigenvalues are monotonically decreasing functions of the reduced masses of their constituent quarks. The experimental meson masses are used to put constraints on the values of quark masses and to predict the masses of some as yet undiscovered mesons. The mass of the B * c meson is predicted to be 6320 ± 10 MeV, and, with les...

Polarized flavor asymmetry ∆¯ u/∆ ¯ d is investigated in a meson-cloud model. A polarized nucleon splits into a ρ meson and a baryon, then the polarized ρ meson interacts with the virtual photon. Because of the difference between the longitudinally polarized distributions ∆¯ u and ∆ ¯ d in ρ, the polarized flavor asymmetry is produced in the nucleon. In addition, we show that the g 2 part of ρ ...

We obtain the D-meson spectral density at finite temperature for the conditions of density and temperature expected at FAIR. We perform a self-consistent coupled-channel calculation taking, as a bare interaction, a separable potential model. The Λc (2593) resonance is generated dynamically. We observe that the D-meson spectral density develops a sizeable width while the quasiparticle peak stays...

Inclusive studies of nuclear photoabsorption have provided clear evidence of medium modifications but the results have not yet been explained in a model independent way. A deeper understanding of the situation is anticipated from a detailed experimental study of meson photoproduction from nuclei in exclusive reactions. Recent results on meson production in photonuclear experiments indicate a la...

As has been confirmed meanwhile by lattice-QCD calculations (see e.g. Ref. [1]), the confinement spectrum of non-exotic quark-antiquark systems has its ground state for scalar mesons well above 1 GeV in the Resonance Spectrum Expansion (RSE). For instance, in the S-wave Kπ RSE amplitude, a broad resonance was predicted slightly above 1.4 GeV [2], which is confirmed by experiment as the K 0 (143...

A bstract We present positivity bounds, derived from the principles of analyticity, unitarity and crossing symmetry, that constrain low-energy constants chiral perturbation theory. Bounds are produced for 2, 3 or more flavours in meson-meson scattering with equal meson masses, up to including next-to-next-to-leading order (NNLO), using second higher derivatives amplitude. enhance bounds by most...

We derive the effective Lagrangian for the low-energy massive meson excitations of the color-flavor-locking (CFL) phase of QCD with 3 flavors of light quarks. We compute the decay constants, the maximum velocities, and the masses of the mesons at large baryon chemical potential µ. The decay constants are linear in µ. The meson maximum velocities are close to that of sound. The meson masses in t...

The confinement mechanism proposed earlier by the author is applied to estimate the possible parameters of the confining SU(3)-gluonic field in an η-meson. For this aim the electric form factor of an η-meson is nonperturbatively computed in an explicit analytic form. The estimates obtained are also consistent with the width of the electromagnetic decay η → 2γ. The corresponding estimates of the...

The excitation spectrum of the nucleon with the spin 1/2 is examined by using the Friedberg-Lee model containing the constituent quark and the scalar meson. An appropriate way of quantization for the non-linear meson field is employed by taking account of the non-topological soliton existed in the classical level. Our model space for the nucleon resonances includes the three-quark plus one-meso...

The chiral symmetry is applied to an extended constituent quark potential model. With random phase approximation (RPA), a small component effect is added to the constituent quark model. To obtain the pseudoscalar π meson as a Goldstone boson, the quark effective potentials are modified in the model to account for the dynamical breaking of chiral symmetry. Also the vector ρ meson is calculated a...