相关论文: Electroexcitation of nucleon resonances

Reliable estimates of neutrino-nucleus reactions in the resonance-excitation region play an important role in many of the on-going and planned neutrino oscillation experiments. We study here neutrino-nucleus reactions in the delta-particle…

The nucleon form factors are calculated using a non-relativistic description in terms of constituent quarks. The emphasis is put on the reliability of present numerical methods used to solve the three-body problem in order to correctly…

We present the first quantum field theory calculation of the pointwise behaviour of the leading-twist parton distribution amplitudes (PDAs) of the proton and its lightest radial excitation. The proton's PDA is a broad, concave function,…

We describe a multi-messenger interpretation of GW170817, which yields a robust lower limit on NS radii. This excludes NSs with radii smaller than about 10.7 km and thus rules out very soft nuclear matter. We stress the potential of this…

We report on the recent results of the hypercentral constituent quark model. The model contains a spin independent three-quark interaction which is inspired by QCD lattice calculations and reproduces the average energy values of the SU(6)…

Relativistic, kinematically complete phenomenological expressions for the dilepton decay rates of nucleon resonances with arbitrary spin and parity are derived in terms of the magnetic, electric, and Coulomb transition form factors. The…

In this article we address the physical basis of the deviation of hadron shapes from spherical symmetry (non-spherical amplitudes) with focus on the nucleon and $\Delta$. An overview of both the experimental methods and results and the…

The magnetic dipole, the electric quadrupole and the Coulomb quadrupole amplitudes for the transition \gamma N\to \Delta are calculated in quenched lattice QCD at \beta=6.0 with Wilson fermions. Using a new method combining an optimal…

We present a unified description of elastic and transition form factors involving the nucleon and its resonances; in particular, the $N(1440)$, $\Delta(1232)$ and $\Delta(1600)$. We compare predictions made using a framework built upon a…

We use inelastic neutron scattering to probe magnetic excitations of an optimally electron-doped superconductor Nd$_{1.85}$Ce$_{0.15}$CuO$_{4-\delta}$ above and below its superconducting transition temperature $T_c=25$ K. In addition to…

We develop an extension of chiral perturbation theory to the $\Delta$(1232)-resonance energy region and apply it to investigate the pion electroproduction off the nucleon ($e^- N \to e^- N\pi$). We present a complete calculation of this…

Background: Until now the knowledge about nucleon resonances with a mass higher than 2 GeV has been scarce. Huge amounts of experimental data of the multipion photoproduction have been accumulated, and more can be expected in the future in…

We present a study of electroexcitation of nucleon resonances with higher spins, in a soft-wall AdS/QCD model, comparing our results with existing data from the CLAS Collaboration at JLab, from MAMI, and other experiments.

In view of the recent results of lattice QCD simulation in the P11 partial wave that has found no clear signal for the three-quark Roper state we investigate a different mechanism for the formation of the Roper resonance in a coupled…

The magnetic dipole, the electric quadrupole and the Coulomb quadrupole amplitudes for the transition $\gamma N\to \Delta$ are evaluated both in quenched lattice QCD at $\beta=6.0$ and using two dynamical Wilson fermions simulated at…

We determine the $\Delta(1232)$ resonance parameters using lattice QCD and the L\"uscher method. The resonance occurs in elastic pion-nucleon scattering with $J^P=3/2^+$ in the isospin $I = 3/2$, $P$-wave channel. Our calculation is…

Phase shifts and inelasticity parameters for $NN$ scattering in the partial-wave channels ${}^3S_1$--${}^3D_1$ and ${}^1S_0$ at energies $T_{\rm lab}$ from zero to about 1 GeV are described within a unified $NN$ potential model assuming the…

We investigate the helicity amplitudes of the $N(1520)$ and $N(1535)$ resonances in the electromagnetic transition process $\gamma^*p\to N^*$, where the $N(1520)$ and $N(1535)$ are assumed to include both the $L=1$ three-quark and $L=0$…

We present the results on the ratios $E_{1+}^{(3/2)}/M_{1+}^{(3/2)}$ and $S_{1+}^{(3/2)}/M_{1+}^{(3/2)}$ for the $\gamma^* N \to \Delta(1232)$ transition at $Q^2\leq 4 (GeV/c)^2$ extracted from the $p(e,e'p)\pi^0$ cross section using two…

The process $ep \to e^{\prime}p^{\prime}\pi^0$ has been measured at $Q^2$ = 6.4 and 7.7 GeV/c$^2$)$^2$ in Jefferson Lab's Hall C. Unpolarized differential cross sections are reported in the virtual photon-proton center of mass frame…