Internal structure of the resonant {Lambda}(1405) state in chiral dynamics

Journal Article · Sun May 15 00:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.83.055202· OSTI ID:21502507

Sekihara, Takayasu ^[1]; Hyodo, Tetsuo ^[2]; Jido, Daisuke ^[3]

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1. Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)
2. Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)
3. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)

The internal structure of the resonant {Lambda}(1405) state is investigated based on meson-baryon coupled-channels chiral dynamics by evaluating density distributions obtained from the form factors of the {Lambda}(1405) state. The form factors are defined as an extension of the ordinary stable particles and are directly evaluated from the current-coupled meson-baryon scattering amplitude, paying attention to the charge conservation of the probe interactions. For the resonant {Lambda}(1405) state we calculate the density distributions in two ways. One is on the pole position of the {Lambda}(1405) in the complex energy plane, which evaluates the resonant {Lambda}(1405) structure without contamination from nonresonant backgrounds, and another is on the real energy axis around the {Lambda}(1405) resonance energy, which may be achieved in experiments. Using several probe interactions and channel decomposition, we separate the various contributions to the internal structure of the {Lambda}(1405). As a result, we find that the resonant {Lambda}(1405) state is composed of widely spread K-bar around N, which gives dominant component inside the {Lambda}(1405), with escaping {pi}{Sigma} component. Furthermore, we consider K-barN bound state without decay channels, with which we can observe the internal structure of the bound state within real numbers. We also study the dependence of the form factors on the binding energy and meson mass. This verifies that the form factor defined through the current-coupled scattering amplitude serves as a natural generalization of the form factor for the resonance state. The relation between the interaction strength and the meson mass shows that the physical kaon mass appears to be within the suitable range to form a molecular bound state with the nucleon through the chiral SU(3) interaction.

• OSTI ID: 21502507
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 83, Issue 5; Other Information: DOI: 10.1103/PhysRevC.83.055202; (c) 2011 American Institute of Physics; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BINDING ENERGY
BOUND STATE
CHARGE CONSERVATION
CHIRALITY
COUPLED CHANNEL THEORY
DECOMPOSITION
DENSITY
DISTRIBUTION
FORM FACTORS
KAONS
LAMBDA-1405 BARYONS
MASS
MESON-BARYON INTERACTIONS
NUCLEAR DECAY
NUCLEONS
PIONS
RESONANCE
SCATTERING AMPLITUDES
SIGMA PARTICLES
SU-3 GROUPS
AMPLITUDES
BARYONS
BOSONS
CHEMICAL REACTIONS
DECAY
DIMENSIONLESS NUMBERS
ELEMENTARY PARTICLES
ENERGY
FERMIONS
HADRON-HADRON INTERACTIONS
HADRONS
HYPERONS
INTERACTIONS
LAMBDA BARYONS
LIE GROUPS
MESONS
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PHYSICAL PROPERTIES
PSEUDOSCALAR MESONS
SIGMA BARYONS
STRANGE MESONS
STRANGE PARTICLES
SU GROUPS
SYMMETRY GROUPS