Short-range and long-range forces in quantum theory: selected topics

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6299551

Hiller, J R

Short-range forces (SRF) are encountered when the effects of the parity-violating (PV) weak neutral current are considered in atomic systems. We consider these and other SRF that are associated with operators that contain delta functions. Identities which convert a delta-function matrix element to that of a global operator are reviewed. Past and possible future applications of such identities are described. It has been found that use of these identities can substantially improve the results obtained with less accurate wave functions. We present a further application to the hyperfine structure of the ground state of lithium where we again find that results are improved by the use of an identity. A long-range force (LRF) is here defined to be one that is associated with a potential V(r) that is asymptotically of the form lambda r/sup -1/(r/sub 0//r)/sup N-1/. We use a dispersion-theoretic approach to study LRF between hadrons due to two-glucon exchange within the framework of quantum chromodynamics. Such an LRF is usually related to the presence of a spectrum of physical states that extends to zero mass. A speculative scheme put forward by Feinberg and Sucher is used to avoid requiring the existence of massless gluons as observable particles. Semi-quantitative expressions for the two-glucon exchange potential between hadrons and, in particular, between two nucleons are obtained. Limits on two-gluon corrections to ..pi..p forward scattering dispersion relations are used to provide an upper bound for lambda, the coupling constant in the nucleon-nucleon potential. For N greater than or equal to 7, expected on heuristic grounds, we obtain the bound lambda less than or equal to 10/sup 6/, which is very weak; gluon effects as treated here do not lead to significant effects in the dispersion-theoretic analysis of ..pi..p scattering.

• Research Organization: Maryland Univ., College Park (USA)
• OSTI ID: 6299551
• Country of Publication: United States
• Language: English

Related Subjects

640305 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Theory-- (-1987)
645203* -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Weak Interactions & Properties
645204 -- High Energy Physics-- Particle Interactions & Properties-Theoretical-- Strong Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
74 ATOMIC AND MOLECULAR PHYSICS
ALGEBRAIC CURRENTS
ALKALI METALS
BASIC INTERACTIONS
CURRENTS
DELTA FUNCTION
DISTANCE
ELEMENTARY PARTICLES
ELEMENTS
FIELD THEORIES
FUNCTIONS
GLUONS
HADRONS
HYPERFINE STRUCTURE
INTERACTION RANGE
INTERACTIONS
LITHIUM
MATRIX ELEMENTS
METALS
NEUTRAL CURRENTS
NUCLEON-NUCLEON POTENTIAL
POSTULATED PARTICLES
POTENTIALS
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
STRONG INTERACTIONS
WAVE FUNCTIONS
WEAK INTERACTIONS
WEAK NEUTRAL CURRENTS