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Kim, Hyun-Chul

Publications and source records attributed to Kim, Hyun-Chul.

6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Mechanical structure of the nucleon and the baryon octet: twist-2 case

We investigate the gravitational form factors (GFFs) of the nucleon and the baryon octet, decomposed into their flavor components, utilizing a pion mean-field approach grounded in the large N c limit of Quantum Chromodynamics (QCD). Our focus is on the contributions from the twist-2 operators to the flavor-triplet and octet GFFs, and we decompose the mass, angular momentum, and D-term form factors of the nucleon into their respective flavors. The strange quark contributions are found to be relatively mild for the mass and angular momentum form factors, while providing significant corrections to the D-term form factor. In the course of examining the flavor decomposition of the GFFs, we uncover that the effects of twist-4 operators play a crucial role. While the gluonic contributions are suppressed by the packing fraction of the instanton vacuum in the twist-2 case, contributions from twist-4 operators are of order unity, necessitating its explicit consideration.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

{Lambda}K*{Lambda}(1116) photoproduction and nucleon resonances

In this presentation, we report our recent studies on the {Lambda}K*{Lambda}(1116) photoproduction off the proton target, using the tree-level Born approximation, via the effective Lagrangian approach. In addition, we include the nine (three- or four-star confirmed) nucleon resonances below the threshold {radical}(s{sub th}){approx_equal}2008 MeV, to interpret the discrepancy between the experiment and previous theoretical studies, in the vicinity of the threshold region. From the numerical studies, we observe that the S{sub 11}(1535) and S11(1650) play an important role for the cross-section enhancement near the {radical}(s{sub th}). It also turns out that, in order to reproduce the data, we have the vector coupling constants gK*S{sub 11}(1535){Lambda} = (7.0{approx}9.0) and gK*S{sub 11}(1650){Lambda} (5.0{approx}6.0).

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

The mass splittings of SU(3) baryons within a chiral soliton model

In the framework of a chiral soliton model ({sub {chi}S}M), the complete mass splittings of SU(3) baryons are investigated, the isospin and SU(3) flavor symmetry breaking being simultaneously considered with a 'model-independent approach'. The dynamical quantities appearing in the expressions for the masses are adjusted to the masses of the baryon octet, the decuplet baryon {Sigma}* and the masses of {Theta}{sup +} and N{sup *} as inputs rather than by extracting them from a calculated self-consistent soliton profile. We estimate the masses of the baryon decuplet and antidecuplet without any further adjustable free parameter and it turns out that calculated mass values of the baryon decuplet are in very good agreement with experimental data.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Tensor properties of the nucleon

We report in the present talk recent results of the tensor properties of the nucleon within the framework of the chiral quark-soliton model. The tensor and anomalous tensor magnetic form factors are calculated for the momentum transfer up to Q{sup 2}{<=}1 GeV{sup 2} and at a renormalization scale of 0.36 GeV{sup 2}. The main results are summarized as follows: the flavor tensor charges of the nucleon are yielded as {delta}u = 1.08, {delta}d = -0.31, {delta}s -0.01, while the up and down anomalous tensor magnetic moments are evaluated as {kappa}{sub T}{sup u} = 3.56 and {kappa}{sub T}{sup d} = 1.83, respectively. The strange anomalous tensor magnetic moment turns out to be {kappa}{sub T}{sup s} 0.2{approx}-0.2, compatible with zero. We discuss their physical implications, comparing them in particular with those from the lattice QCD.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Nucleon Properties in Nuclear Matter

We present recent studies on the effective mass of the nucleon in infinite and homogeneous nuclear matter and its relation to nuclear matter properties within the framework of the in-medium modified Skyrme model. Medium modifications are achieved by introducing optical potential for pion fields and parametrization of the Skyrme parameter in nuclear medium. The present approach is phenomenologically well justified by pion physics in nuclear matter and describe successfully bulk nuclear matter properties.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗