Related papers: Strange vector currents and the OZI-rule
We consider an Ising spin-chain in a random transverse magnetic field and compute the zero temperature wave vector and frequency dependent dynamic structure factor numerically by using Jordan-Wigner transformation. Two types of…
Precise measurements of electron and positron scattering, including parity violation, offer great promise in the search for physics beyond the Standard Model. In this context it is crucial to understand the corrections which might arise…
We illustrate the progress of covariant QCD phenomenology for the description of meson coupling constants and form factors. As examples, we discuss the $\rho\pi\pi$ and $\gamma \pi\rho$ interactions, the $\rho$ contribution to the pion…
We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak…
Unusual constituent quark axial current couplings to light vector mesons, $\rho$ and $\omega$, are derived in the vacuum and under weak magnetic field by considering a quark-antiquark interaction mediated by a non perturbative gluon…
Despite some success in explaining the observed polarisation angle swing of radio pulsars within the geometric rotating vector model, many deviations from the expected S-like swing are observed. In this paper we provide a simple and…
We review the role of two-photon exchange (TPE) in electron-hadron scattering, focusing in particular on hadronic frameworks suitable for describing the low and moderate Q^2 region relevant to most experimental studies. We discuss the…
We calculate the vector and scalar form factors of the pion to two loops in Chiral Perturbation Theory. We estimate the unknown O(p^6) constants using resonance exchange. We make a careful comparison to the available data and determine two…
Charge form factors corresponding to proton density distributions in exotic nuclei, such as $^{6,8}$He, $^{11}$Li, $^{17,19}$B and $^{14}$Be are calculated and compared. The results can be used as tests of various theoretical models for the…
We calculate the electromagnetic form factors of a bound proton. The Chiral Quark-Soliton model provides the quark and antiquark substructure of the proton, which is embedded in nuclear matter. This procedure yields significant…
A quantitative understanding of charge-symmetry breaking is an increasingly important ingredient for the extraction of the nucleon's strange vector form factors. We review the theoretical understanding of the charge-symmetry-breaking form…
Neutron scattering on exotic nuclides is a class of processes which can not be studied directly now and in any observable future. Resonance proton scattering of exotic nuclide on a thick target in inverse kinematics can be used to infer the…
Possibilities to extract information on the strange form factors of the nucleon from neutrino (antineutrino) inelastic scattering on nuclei, in an energy range from 200 MeV to 1 GeV and more, are investigated in detail. All calculations are…
We present a relativistic interpretation for why the proton's ratio of electric to magnetic form factor falls and for why the ratio of the Pauli to Dirac form factor varies as 1/Q. Reproducing the observed electric form factor of the…
The contributions of direct knockout processes, in addition to the diffractive production and one-pion-exchange processes associated with the phi-rho-pi and phi-gamma-pi couplings, to the polarization observables of the phi photoproduction…
We calculate the correlator between two external vector-currents having the quantum-numbers of a charged kaon. We give the renormalized expression to two loops in standard chiral perturbation theory in the isospin limit, which, as a…
We investigated the impact of a constant external magnetic field on the dressed propagators of up-, down-, and strange quarks. In the weak field limit, we derive a general momentum-space representation for the propagator and numerically…
We present the experimental status of electromagnetic hadron form factors. New and surprising results, based on polarization measurements, have been recently obtained for the electric proton and neutron form factors. In particular, the…
We analyze the elastic scattering of particles interacting with nuclei through vector and axial currents with overall couplings of the order of the Standard Model weak interaction, or smaller; the dominant contribution to the elastic cross…
We revisit the contribution of axial-vector mesons to the hyperfine splitting of muonic hydrogen. We focus our attention on the doubly-virtual asymptotic behavior of the relevant form factors of axial-vector mesons, together with their…