相关论文: Charge splitting in ${\pi}N\Delta$ formfactor

The reaction gamma p -> p pi0 gamma' has been measured with the Crystal Ball / TAPS detectors using the energy-tagged photon beam at the electron accelerator facility MAMI-B. Energy and angular differential cross sections for the emitted…

Charge excitations in a two dimensional electron gas, under a quantizing magnetic field and in the fractional quantum Hall effect regime, flow in one dimensional-like strips along the edges of the sample. These excitations (quasiparticles)…

We address the issue of the scaling behavior of the nucleon electromagnetic form factors (FFs). We propose a consistent Lagrangian of the electromagnetic N\Delta(1232)-interaction possessing all the internal symmetries of the spin-3/2…

One-dimensional metals, such as quantum wires or carbon nanotubes, can carry charge in arbitrary units, smaller or larger than a single electron charge. However, according to Luttinger theory, which describes the low-energy excitations of…

Employing the standard hard-scattering approach and the running coupling method we calculate a class of power-suppressed corrections $\sim 1/Q^{2n},n=1,2,3,...$ to the electromagnetic $\pi^0\gamma$ transition form factor (FF)…

Phase transitions of small isolated systems are signaled by the shape of the caloric equation of state e^*(T), the relationship between the excitation energy per nucleon e^* and temperature. In this work we compare the experimentally…

We set up a general framework to describe $\pi\pi$ scattering below 1 GeV based on chiral low-energy expansion with possible spin-0 and 1 resonances. Partial wave amplitudes are obtained with the $N/D$ method, which satisfy unitarity,…

Scattering and production amplitudes involving scalar resonances are known, according to Watson's theorem, to share the same phase $\delta(s)$. We show that, at low energies, the production amplitude is fully determined by the combination…

The dynamical phase diagram of the fractional Langevin equation is investigated for harmonically bound particle. It is shown that critical exponents mark dynamical transitions in the behavior of the system. Four different critical exponents…

We evaluate the possible deviation (from the conventional Cahn's result) of the phase between the one-photon-exchange and the `nuclear' high energy $pp$ scattering amplitudes in a small $t\to 0$ region caused by a more complicated (not just…

We report on measurements of event-by-event charge fluctuations in $\pi^{+}\rp$ and $\rK^{+}\rp$ collisions at 250 GeV/$c$. The dependence of these fluctuations on the size of the rapidity windows are presented for the first time in the…

We investigate low-energy $N\phi$ scattering driven by a pole-enhanced triangle-like diagram, in which the two-Kaon-exchange contribution is promoted by the near-threshold $\Lambda(1405)$ pole in the $N\bar K$ subsystem. Using an unphysical…

Topological charge distributions in 2 dimensional CP^2 model with theta-term is calculated. In strong coupling regions, topological charge distribution is approximately given by Gaussian form as a function of topological charge and this…

The phase variation with angle of hadronic amplitudes is studied with a view to understanding the underlying physical quantities which control it and how well it can be determined in free space. We find that unitarity forces a moderately…

The Coulomb gap in a donor-acceptor model with finite charge transfer energy $\Delta$ describing the electronic system on the dielectric side of the metal-insulator transition is investigated by means of computer simulations on two- and…

We derive a closed, model space independent, expression for the electromagnetic correction factor $\delta $ to the scattering length $a$ extracted from a hydrogenic atom with an extended charge to order $\alpha ^2$ and $a^3$ in the limit of…

We present the results of energy-dependent and single-energy partial-wave analyses of pi-N elastic scattering data with laboratory kinetic energies below 2.1 GeV. We have considered the effect of adding dispersion-relation constraints…

We perform a complete calculation of charge symmetry breaking effects for the reaction pn -> d pi0 at leading order in chiral perturbation theory. A new leading-order operator is included. From our analysis we extract \delta m_N^{str}, the…

Measurements of inclusive electron-scattering cross sections using hydrogen and deuterium targets in the region of the Delta(1232) resonance are reported. A global fit to these new data and previous data in the resonance region is also…

We present results of the Nijmegen partial-wave analyses of all NN scattering data below Tlab = 500 MeV. We have been able to extract for the first time the important np phase shifts for both I = 0 and I = 1 from the np scattering data…