相关论文: Charge Symmetry Breaking and Parity Violating Elec…
For the first time, charge symmetry breaking terms in parton distribution functions have been included in a global fit to high energy data. We review the results obtained for both valence and sea quark charge symmetry violation, and we…
We update the predictions of the SU(2) baryon chiral perturbation theory for the dipole polarisabilities of the proton, $\{\alpha_{E1},\,\beta_{M1}\}_p=\{11.2(0.7),\,3.9(0.7)\}\times10^{-4}$fm$^3$, and obtain the corresponding predictions…
The scaling of nuclear spin-dependent parity violating effects with increasing nuclear charge $Z$ is discussed in two series of isovalent open-shell diatomic molecules. The parameter $W_\mathrm{a}$ characterising the strength of parity…
We calculate the nucleons' electromagnetic polarizabilities in heavy baryon chiral perturbation theory including all terms to order ${\cal O} (q^4)$. The chiral prediction of the electric polarizabilities for the neutron and the proton are…
We study electromagnetic form factors of protons in proton-nucleus scattering via analysing of experimental cross-sections of accompanying bremsstrahlung photons. A new bremsstrahlung model for proton-nucleus scattering is developed, where…
We present a theoretical analysis of signals for CPT and Lorentz violation in g-2 and charge-to-mass-ratio experiments on electrons and positrons in Penning traps. Experiments measuring anomaly frequencies are found to be the most sensitive…
Chiral symmetry serves as a guiding principle in low-energy hadron dynamics. An effective lagrangian, which explicitly breaks chiral symmetry via a small mass term, allows for a systematic method of calculating higher order corrections to…
The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The…
Several parameters characterizing the strangeness content of the nucleon have been calculated in the chiral constituent quark model with configuration mixing (\chiCQM_{config}) which is known to provide a satisfactory explanation of the…
Heavy baryon chiral perturbation theory ($\chi$PT), where the $\Delta$ resonance is included, is used in order to examine the axial charged-current component of the weak interaction process at low neutrino energies. At leading chiral order…
A purely left-chiral model of the weak interactions is used to show that the total parity-violating asymmetry in quark-quark scattering must grow with increasing energy. In the absence of other new physics, non-observation of a large…
Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic…
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 lecture, I review progress made in the calculations of the parity-violating meson-nucleon interaction regions. The underlying framework is the topological chiral soliton model of the nucleon. Emphasis is put on the computation of…
The parity violation programs at MIT-Bates, Jefferson Lab and Mainz are presently focused on developing a better understanding of the sea-quark contributions to the vector matrix elements of nucleon structure. The success of these programs…
In a global analysis of the latest parity-violating electron scattering measurements on nuclear targets, we demonstrate a significant improvement in the experimental knowledge of the weak neutral-current lepton-quark interactions at low…
The measurement of parity violation in the helicity dependence of electron-nucleon scattering provides unique information about the basic quark structure of the nucleons. In this review, the general formalism of parity-violating electron…
The pseudoscalar particles pions, kaons and the $\eta$-particle are considerably lighter than the other hadrons such as protons or neutrons. Their lightness was understood as a consequence of approximate chiral symmetry breaking. This led…
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…
Results of charge form factors calculations for several unstable neutron-rich isotopes of light, medium and heavy nuclei (He, Li, Ni, Kr, Sn) are presented and compared to those of stable isotopes in the same isotopic chain. For the lighter…