Instantons and fermion densities

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

OSTI ID:5984350

De Carvalho, A; Alberto, C

Using semiclassical methods we investigate the effects of imposing a fixed charge density constraint on field theories that posses instanton-like classical solutions. We examine the two-dimensional Abelian-Higgs model and discuss the role played by the chemical potential (..mu..) of massless fermions in a dilute-gas approximation to the functional integral. Mass generation is discussed and a suppression of vortex density is shown to occur as we increase ..mu... We then examine the one-instanton amplitude in QCD and discover that, for a fixed ..mu.., the instanton density is exponentially suppressed in both the heavy and light quark cases, a phenomenon due to screening. We give arguments to support the contention that in the massless limit instantons should be competely suppressed and only virtual tunnelings (instanton-antiinstanton pairs) should be important. Finally we briefly discuss the application of our results to the investigation of a possible neutron-quark matter phase transition.

• Research Organization: Princeton Univ., NJ (USA)
• OSTI ID: 5984350
• Country of Publication: United States
• Language: English

Related Subjects

645400* -- High Energy Physics-- Field Theory
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
CHARGE DENSITY
DENSITY
ELEMENTARY PARTICLES
FERMIONS
FIELD THEORIES
HADRONS
HIGGS MODEL
INSTANTONS
MATHEMATICAL MODELS
NEUTRONS
NUCLEONS
PARTICLE MODELS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POSTULATED PARTICLES
QUANTUM CHROMODYNAMICS
QUANTUM FIELD THEORY
QUARKS
QUASI PARTICLES