/ital s//r arrow//ital d//gamma/ contribution to hyperon radiative decays: A QCD-sum-rule approach

Journal Article · Sat Jul 01 04:00:00 EDT 1989 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.40.106· OSTI ID:5938815

Goldman, C; Escobar, C O

We analyze, using the method of the QCD sum rules, the short-distancecontribution /ital s//r arrow//ital d//gamma/ to the hyperon radiative decays/Sigma//sup +//r arrow/p/gamma/ and /Xi//sup /minus///r arrow//Sigma//sup /minus///gamma/. A morereliable estimate of this contribution is obtained, giving branching ratiosthat are larger than obtained before for the same process, although still smallwhen compared with experimental data. The asymmetry parameter /alpha/ turnsout to depend on the decay considered and surprisingly is equal to /minus/1 for/Sigma//sup +//r arrow/p/gamma/, for dynamical reasons which we discuss at length.

• Research Organization: Instituto de Fiiaasica da Universidade de Sao Paulo, Caixa Postal 20516, 01498 Sao Paulo, SaBo Paulo, Brazil(BR)
• OSTI ID: 5938815
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 40:1; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645202* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Electromagnetic Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
BARYONS
BRANCHING RATIO
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FIELD THEORIES
HADRONS
HYPERONS
NUCLEONS
PROTONS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
RADIATIVE DECAY
SIGMA BARYONS
SIGMA PARTICLES
SIGMA PLUS PARTICLES
STRANGE PARTICLES
SUM RULES