Related papers: The u-d quark mass difference and nuclear charge s…
We demonstrate that a $u-d$ mass difference (which we estimate to be about 4 MeV) within quantum loops, can reproduce the effects of the Coleman-Glashow electromagnetic tadpole operator.
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 quark-meson coupling model which we have developed previously is extended to incorporate the $\delta$ meson. It is then used to study the Nolen-Schiffer anomaly and isospin symmetry breaking in nuclear matter. We find that, in…
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…
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.…
{}From the deep-inelastic momentum sum rule and the trace anomaly of the energy-momentum tensor, I derive a separation of the nucleon mass into the contributions of the quark and gluon kinetic and potential energies, the quark masses, and…
We study 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, using the quark-meson coupling model. The calculation…
The scale of a phenomenologically successful charge-symmetry-violating nucleon-nucleon interaction, that attributed to meson exchange with a $\Delta I =1$ rho-omega transition, is set by the Coleman-Glashow SU(2) breaking tadpole mechanism.…
Effects of charge symmetry breaking associated with the $u$ and $d$ quark mass difference in the elastic form factors of the pion and kaon are presented. We use a confining version of the Nambu--Jona-Lasinio model. The pion and kaon are…
The nucleon tensor charge, $g_T$, is an important quantity in the search for beyond the Standard Model tensor interactions in neutron and nuclear $\beta$-decays as well as the contribution of the quark electric dipole moment (EDM) to the…
Using a quark model, we calculate symmetry breaking effects in the valence quark distributions of the nucleon. In particular, we examine the breaking of the quark model SU(4) symmetry by color magnetic effects, and find that color magnetism…
Charge symmetry breaking (CSB) effects associated with the $u$ and $d$ quark mass difference are investigated in the quark distribution functions and spacelike electromagnetic form factors of the pion and kaon. We use a confining version of…
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…
QCD sum rules using polynomial kernels are used to evaluate the strong part of the proton-neutron mass difference DeltaM_np in a model independent fashion. The result for the mass difference turns out to depend sensitively on the value of…
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.…
We calculate the nucleon self-energies in isospin-asymmetric nuclear matter using QCD sum rules. Taking the difference of these for the neutron and proton enables us to express the potential part of the nuclear symmetry energy in terms of…
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…
Charge-symmetry breaking in the nucleon-nucleon force is investigated within an effective field theory, using a classification of isospin-violating interactions based on power-counting arguments. The relevant charge-symmetry-breaking…
In order to investigate the charge symmetry breaking (CSB) in the short range part of the nuclear force, we calculate the difference of the masses of the neutron and the proton, $\Delta {\rm M}$, the difference of the scattering lengths of…
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…