相关论文: Charge Independence and Symmetry of Nuclear Forces
Charge independence and charge symmetry are approximate symmetries of nature, violated by the perturbing effects of the mass difference between up and down quarks and by electromagnetic interactions. The observations of the symmetry…
The role of the off-shell dependence of $\rho-\omega$ mixing in the charge symmetry breaking nucleon-nucleon potential is discussed. It is shown that models describing the off-shell dependence of $\rho-\omega$ mixing are not sufficient to…
The $q^2$ dependence of the $\rho-\omega$ mixing amplitude is analyzed with the use of the QCD sum rules and the dispersion relation. Going off shell the mixing decreases, changes sign at $q^2 \simeq 0.4 m_{\rho}^2 > 0$ and is negative in…
We investigate the effects of charge independence and charge symmetry breaking in neutron-rich matter. We consider neutron and proton properties in isospin-asymmetric matter at normal densities as well as the high-density neutron matter…
A brief review of the isospin symmetry breaking in hadrons and nuclei is given with emphasis on the $u-d$ quark mass difference. The off-shell $\rho^0-\omega$ mixing is studied as a typical example of the symmetry breaking, and its…
The consequences of the charge symmetry breaking effects of the mass difference between the up and down quarks and electromagnetic effects for searches for strangeness form factors in parity violating electron scattering from the proton are…
The quark-loop contribution to the $\rho^0-\omega$ mixing self-energy function is calculated using a phenomenologically successful QCD-based model field theory in which the $\rho^0$ and $\omega$ mesons are composite $\bar{q}q$ bound states.…
Interplay between the dependence of symmetry energy on density and the variation of nucleonic densities across nuclear surface is discussed. That interplay gives rise to the mass dependence of the symmetry coefficient in an energy formula.…
We discuss charge symmetry and charge independence breaking in an effective field theory approach for few-nucleon systems. We systematically introduce strong isospin-violating and electromagnetic operators in the theory. The charge…
Charge symmetry breaking in the strong interaction occurs because of the difference between the masses of the up and down quarks. At present the Standard Model can't explain the observed mass pattern (M(n), M(p), m(u), m(d) etc.) and their…
The effects of charge independence breaking of nucleon-nucleon interaction on the bulk properties of nuclear matter are investigated. Our results indicate that at high densities, the inclusion of charge dependence in the nucleon-nucleon…
Using a quark model, we study the effect of charge symmetry breaking on the valence quark distributions of the nucleon. The effect due to quark mass differences and the Coulomb interaction of the electrically charged quarks is calculated…
The binding energy differences of the valence proton and neutron of the mirror nuclei, $^{15}$O -- $^{15}$N, $^{17}$F -- $^{17}$O, $^{39}$Ca -- $^{39}$K and $^{41}$Sc -- $^{41}$Ca, are calculated using the quark-meson coupling (QMC) model.…
Within a broad class of models we show that the amplitude for rho^0-omega mixing must vanish at the transition from timelike to spacelike four momentum. Hence in such models the mixing is either zero everywhere or is necessarily…
Energy in nuclear matter is, in practice, completely characterized at different densities and asymmetries, when the density dependencies of symmetry energy and of energy of symmetric matter are specified. The density dependence of the…
Charge symmetry breaking (CSB) in the strong interaction occurs because of the difference between the masses of the up and down quarks. The use of effective field theories allows us to follow this influence of confined quarks in hadronic…
A charge-symmetry-breaking nucleon-nucleon force due to the up-down quark mass difference is evaluated in the quark cluster model. It is applied to the shell-model calculation for the isovector mass shifts of isospin multiplets and the…
It is pointed out that the meson mixing matrix elements usually considered responsible for the bulk of the observed few-body charge symmetry breaking are naturally $q^2$-dependent in QCD. For $\pi^o-\eta$ mixing, using the usual…
The charge symmetry breaking and charge independence breaking N-N ^1S_0 scattering length differences, Delta a_{CSB} and Delta a_{CIB}, are calculated by a resonating group method with a quark cluster model. By adding the QED-QCD…
It is shown, in a model independent way, that the large difference in rho and omega widths gives rise to a new source of momentum dependence for the rho-omega mixing matrix element. The q^2 dependence arising due to the meson widths leads…