Two related questions: Centrifugal barriers and the spin of the. cap omega. /sup -/

Journal Article · Wed Sep 01 04:00:00 EDT 1976 · Phys. Rev., D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.14.1323· OSTI ID:7147428

Mac Gregor, M H

The centrifugal-barrier concept of nuclear physics is commonly assumed to apply also to elementary-particle physics; e.g., SU(3) calculations of decay coupling constants include explicit barrier factors. However, this assumption may be incorrect, for both theoretical and experimental reasons--theoretically, nuclear rotations are adiabatic and nuclear decays have a small energy release, whereas elementary-particle rotations are highly nonadiabatic and particle decays have an enormous energy release; experimentally, nuclear resonances get narrower with increasing spin values, whereas hadron resonances get systematically broader--and this hadron result holds uniformly for all values of baryon number and strangeness. By assuming that baryon resonances each contain three spin-1/2 quarks, and by studying the spin, width, and mass characteristics of these resonances, we arrive at a two-fold experimental difference between rotationless (l = 0) and rotational (l > 0) baryon excitations: (1) The l = 0 excitations are narrower (in contrast to the situation in nuclear physics); (2) the l = 0 mass values are quantized, whereas the l > 0 mass values are not. The quantization of the l = 0 baryon levels shows a correlation between masses and spin values S; in particular, narrow S = 3/2 levels appear at about 1530 MeV, and S = 1/2 levels appear at about 1670 MeV. This suggests that the ..cap omega../sup -/, with a mass of about 1670 MeV, has spin S/sub ..cap omega../ = 1/2 rather than the SU(3)-mandated value S/sub ..cap omega../ = 3/2. These results underscore the importance of carrying out a direct measurement of spin of the ..cap omega../sup -/; such a measurement appears to be experimentally feasible. (AIP)

• Research Organization: Lawrence Livermore Laboratory, Livermore, California 94550
• OSTI ID: 7147428
• Journal Information: Phys. Rev., D; (United States), Journal Name: Phys. Rev., D; (United States) Vol. 14:5; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645206* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions
Baryon No. = 1-- (-1987)
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
BARYON RESONANCES
BARYONS
ELEMENTARY PARTICLES
ENERGY LEVELS
FERMIONS
HADRONS
HYPERONS
LIE GROUPS
MASS
MASS SPECTRA
OMEGA MINUS
OMEGA PARTICLES
PARTICLE PROPERTIES
PARTICLE WIDTHS
RESONANCE PARTICLES
REST MASS
SPECTRA
SPIN
STRANGE PARTICLES
STRANGENESS
SU GROUPS
SU-3 GROUPS
SYMMETRY GROUPS