arXiv subjects
Publications and source records attributed to Hungchong Kim.
Motivated by the recently constructed interpolation field for S$_{11}$(1535), we propose a new interpolating field for $Λ$(1405). Using this current, we calculate the mass of $Λ$(1405) based on the conventional QCD sum rule analysis. By calculating the Wilson coefficients up to dimension 8 operators and taking into account the mass corrections from s-quark, we find the calculated mass of $Λ$(1405) to be very close to its experimental value.
The $Δ$ decay in the nuclear medium is calculated in the relativistic meson-nucleon model. The delta spreading width is calculated and compared with the Pauli-blocked $π$N decay width. The influence of relativistic mean fields is also studied. We stress the importance of understanding the delta spreading width in interpreting experiments involving delta resonances.
We derive the contribution of $Δ$-h excitations to quasielastic charged-current neutrino-nucleus scattering in the framework of relativistic mean-field theory. We discuss the effect of $Δ$ production on the determination of the axial mass $M_A$ in neutrino scattering experiments.
We compute the cross section for the charged-current reaction ${}^{12}{\rm C}(ν_μ,μ^{-})$ near threshold using a relativistic mean-field formalism. A reduced value of the nucleon mass in the medium --- coupled to the finite muon mass --- leads to a 30\% reduction in the cross section relative to a free Fermi-gas estimate. Isovector RPA correlations, which are strongly repulsive at these momentum transfers, reduce the cross section by an additional 15-30\%. Hence, relativistic nuclear-structure effects can account for the more than a factor-of-two reduction in the cross section recently reported by the LSND collaboration.
Charged-current cross sections are calculated for quasielastic neutrino and antineutrino scattering using a relativistic meson-nucleon model. We examine how nuclear-structure effects, such as relativistic random-phase-approximation (RPA) corrections and momentum-dependent nucleon self-energies, influence the extraction of the axial form factor of the nucleon. RPA corrections are important only at low-momentum transfers. In contrast, the momentum dependence of the relativistic self-energies changes appreciably the value of the axial-mass parameter, $M_A$, extracted from dipole fits to the axial form factor. Using Brookhaven's experimental neutrino spectrum we estimate the sensitivity of M$_A$ to various relativistic nuclear-structure effects.
Inclusive quasielastic response functions are calculated for electron scattering in a relativistic model including momentum dependent scalar and vector mean fields. The momentum dependence of the mean fields is taken from Dirac optical fits to proton nucleus scattering and is important in describing data at momentum transfers of 1 GeV/c or larger. Our simple model is applicable for quasielastic scattering over a large range of momentum transfers.