Related papers: Isospin Violations in the Pion-Nucleon System
The effects of isospin violation on the neutral weak magnetic form factor of the proton are studied using two-flavour chiral perturbation theory. The first nonzero contributions appear at O(p^4) in the small-momentum expansion, and the…
Strong interactions preserve an approximate isospin symmetry between up ($u$) and down ($d$) quarks, part of the more general flavor symmetry. In the case of $K$ meson production, if this isospin symmetry were exact, it would result in…
Using results from the chiral perturbation theory for the s-wave interaction and the delta-resonance model for the p-wave interaction of pions with nucleons, we have evaluated the spectral functions of pions in asymmetric nuclear matter…
The effects of isospin-symmetry breaking on the observables for parity-violating electron scattering are investigated within the framework of the nuclear shell model for 12C, 16O, and 28Si. Contributions due to mixing with low-lying states…
On the basis of a next-to-leading-order calculation in chiral perturbation theory, the first complete analysis of isospin breaking for direct CP violation in K^0 -> 2 pi decays is performed. We find a destructive interference between three…
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…
It is demonstrated that there is a dynamic isospin breaking effect in the near threshold $\gamma^{*} N\to \pi N$ reaction due to the mass difference of the up and down quarks, which also causes isospin breaking in the $\pi N$ system. The…
The relations between the value of T- and P-violating correlations in neutron scattering and different models of CP violation are discussed. It is shown that a specific structure of CP-odd interactions gives the possibility to obtain the…
We have studied the influences of isospin symmetry breaking of nucleon-nucleon interaction on the various properties of asymmetrical nuclear matter and $\beta$-stable matter. For asymmetrical nuclear matter, it is found that by including…
High energy reactions may produce a state around the collision point that is best described by a classical pion field. Such a field might be an isospin rotated vacuum of the chiral $\sigma$-model or, as discussed in this work, a solution of…
We investigate the size of potential higher pseudoscalar resonance contaminations of the estimates of isospin-conserving and isospin-violating $\pi NN$ couplings obtained using the 3-point function method in QCD sum rules. For the…
We determine the strong-isospin violating component of the neutron-proton mass difference from fully-dynamical lattice QCD and partially-quenched QCD calculations of the nucleon mass, constrained by partially-quenched chiral perturbation…
The simple model describing charge independence and charge symmetry breaking of the pion-nucleon coupling constant is proposed. The model, which has simple physical meaning and foundation, suggests directly proportional dependence of the…
This is the first of a series of papers devoted to a detailed analysis of isospin-breaking effects in the $\pi \pi$ scattering amplitude and the vector form factor of the pion. Isospin breaking originates from the mass difference between up…
We investigate the isospin-violating mixing of the light scalar mesons a0(980) and f0(980) within the unitarized chiral approach. Isospin-violating effects are considered to leading order in the quark mass difference and electromagnetism.…
The manifestation of pseudospin-symmetry in proton-nucleus scattering is discussed. Constraints on the pseudospin-symmetry violating scattering amplitude are given which require as input cross section and polarization data, but no…
Coulomb and mass difference corrections to low-energy pion-nucleon scattering are calculated and compared with previous work including potential models, dispersion relation methods and chiral perturbation theory calculations. Particular…
Using an isospin-dependent transport model, we study isospin effects on two-nucleon correlation functions in heavy-ion collisions induced by neutron-rich nuclei at intermediate energies. We find that these correlation functions are…
The inclusive spectra of preequilibrium nucleons produced in low-energy antiproton-nucleus collisions are thoroughly investigated within the framework of the Lanzhou quantum molecular dynamics model for the first time. All possible reaction…
Searches for dark matter scattering off nuclei are typically compared assuming that the dark matter's spin-independent couplings are identical for protons and neutrons. This assumption is neither innocuous nor well motivated. We consider…