Structure of hyperon resonances

Miscellaneous · Wed Jan 01 00:00:00 EST 1992

OSTI ID:7296239

Umino, Y

Baryons are composite objects. Although this fact has been verified beyond doubt, the authors are far from understanding its internal structure using first principles based on Quantum Chromodynamics (QCD). This theory of strong interactions governs the dynamics of quarks and gluons with which the authors ultimately would like to describe nuclear physics. Any realistic model of baryons should therefore simulate QCD and somehow make connections to nuclear physics. In this work, the authors use a candidate for one such model, the chiral bag model, to examine whether it can offer any valuable insights into the structure of hyperon resonances, especially those that might play important roles in hypernuclear physics. The authors begin by calculating the mass spectrum of negative parity hyperons in this model calculation are discussed and an estimate is made of the magnitude of theoretical uncertainty in the results. After exploring how the masses and the spin-flavor compositions of the hyperon resonances are determined, the authors find a reasonable fit to the mass spectrum. However, a comparison with another model prediction indicates that this alone is insufficient to determine the structure of excited hyperons. Therefore, the authors calculate some strong interaction properties and radiative decay widths of the two lightest hyperon resonances. Both of these quantities are sensitive to the spin-flavor composition of the hyperons and the former are of interest to low energy KN interactions while the latter also test model dependent electromagnetic transition operators. The authors also comment on the complicated structure of the [Lambda](1405) and argue that experimental determination of hyperon radiative widths would provide an ideal probe to explore the structure of excited strange baryons.

• Research Organization: State Univ. of New York, Stony Brook, NY (United States)
• OSTI ID: 7296239
• Resource Relation: Other Information: Thesis (Ph.D.)
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
HYPERONS
RESONANCE
STRONG INTERACTIONS
BAG MODEL
QUANTUM CHROMODYNAMICS
BARYONS
BASIC INTERACTIONS
COMPOSITE MODELS
ELEMENTARY PARTICLES
EXTENDED PARTICLE MODEL
FERMIONS
FIELD THEORIES
HADRONS
INTERACTIONS
MATHEMATICAL MODELS
PARTICLE MODELS
QUANTUM FIELD THEORY
QUARK MODEL
STRANGE PARTICLES
662240* - Models for Strong Interactions- (1992-)