相关论文: Nucleon Charge Symmetry Breaking and Parity Violat…
The modification of the Paschos-Wolfenstein relation is investigated when the charge symmetry violations of valence and sea quark distributions in the nucleon are taken into account. We also study qualitatively the impact of charge symmetry…
Parity-violating (PV) interactions among quarks in the nucleon induce a PV $\gamma NN$ coupling, or anapole moment (AM). We compute electroweak gauge-independent contributions to the AM through ${\cal O}(1/\lamchis)$ in chiral perturbation…
The scattering of a neutrino on atomic electrons is considered in the situation where the energy transferred to the electrons is comparable to the characteristic atomic energies, as relevant to the current experimental search for neutrino…
Some recent experimental and theoretical work on 1) charge symmetry-breaking, 2) parity non-conservation, and 3) searches for breaking of time reversal invariance are reviewed. The examples illustrate the uses of symmetry to learn about…
After almost five decades of study of parity violation in hadronic systems, the determination of the seven weak meson-nucleon couplings is still incomplete. Whereas parity violation in nuclear systems is complicated by the intricacies of…
The forward--backward asymmetry in n p --> d pi^0, which must be zero in the center-of-mass system if charge symmetry is respected, has been measured to be [17.2 +/- 8 (stat) +/- 5.5 (sys)] * 10^{-4}, at an incident neutron energy of 279.5…
In this study, we performed calculations and analyses of the structure functions of polarized nucleons and light nuclei, specifically $^3$He and $^3$H, using second-order Feynman diagrams. Our investigation focused on two main aspects:…
We review a recent theoretical determination of the strange quark content of the electromagnetic form factors of the nucleon. These are compared with a global analysis of current experimental measurements in parity-violating electron…
Parity-even time reversal violation (TRV) in the nucleon-nucleon interaction is reconsidered. The TRV $\rho$-exchange interaction on which recent analyses of measurements are based is necessarily also charge-symmetry breaking (CSB). Limits…
The strange quark contributions to the electromagnetic form factors of the proton are ideal quantities to study the role of hidden flavor in the properties of the proton. This has motivated intense experimental measurements of these form…
Several new proton-proton parity violation experiments are presently either being performed or are being prepared for execution in the near future. Similarly, a new measurement of the parity-violating gamma-ray asymmetry in polarized…
Strange quark contributions to neutrino(antineutrino) scattering are investigated on the nucleon level in the quasi-elastic region. The incident energy range between 500 MeV and 1.0 GeV is used for the scattering. All of the physical…
The extraction of the strangeness form factors from parity violating elastic electron-proton scattering is sensitive to the electromagnetic form factors at low Q^2. We provide parameterizations for the form factors and uncertainties,…
The Gottfried sum rule violation reported by the New Muon Collaboration(NMC) was interpreted as indication for a flavour asymmetry of the sea quark in the nucleons. We investigate the alternative possibility that isospin symmetry between…
We use local quark-hadron duality to calculate the nucleon structure function as seen by neutrino and muon beams. Our result indicates a possible signal of charge symmetry violation at the parton level in the very large x region.
Effect of bound nucleon internal structure change on nuclear structure functions is investigated based on local quark-hadron duality. The bound nucleon structure functions calculated for charged-lepton and (anti)neutrino scattering are all…
Applying general symmetry properties of electromagnetic interaction, information from electron proton elastic scattering data can be related to charge asymmetry in the annihilation channels $e^++e^-\leftrightarrow \bar p + p$ and to the…
The status of Compton scattering by the nucleon at energies of the first and second resonance is summarized. In addition to a general test of dispersion theories and a precise determination of polarizabilities, the validities of four…
Parity violating electron-deuteron scattering can potentially provide a clean access to electroweak couplings that are sensitive to physics beyond the Standard Model. However hadronic effects can contaminate their extraction from…
The symmetries of the $t=1$ and $t=0$ pair-fields are different. The consequences for rotational spectra are discussed. For $t=1$, the concept of spontaneous breaking and subsequent restoration of the isospin symmetry turns out to be…