Pion condensates

Technical Report · Wed Jan 01 04:00:00 EST 1975

DOI:https://doi.org/10.2172/7350441· OSTI ID:7350441

Brown, G E; Weise, W

A review of recent developments which indicate that neutron or nuclear matter at sufficiently high density undergoes a phase transition into a pion condensate is presented. Following an introductory discussion of the simplest possible models, realistic features are added stepwise, like the role of short-range nucleon-nucleon correlations and the importance of the ..delta..(1230) isobar. Results of realistic calculations of the critical density for pion condensation in neutron matter are summarized, which show that the phase transition appears around or beyond twice the density of nuclear matter. The description of pion condensation is summarized within the framework of the sigma model, based on chiral symmetry, and generalized to include short-range correlations and ..delta..(1230) isobars. This model permits construction of the equation of state for pion condensed neutron matter. The presence of a pion condensate generally leads to a softening of the equation of state. Some implications on the structure of neutron stars are studied.

• Research Organization: State Univ. of New York, Stony Brook (USA). Dept. of Physics
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• OSTI ID: 7350441
• Report Number(s): COO-3001-125
• Country of Publication: United States
• Language: English

Related Subjects

653002* -- Nuclear Theory-- Nuclear Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYON RESONANCES
BARYONS
BOSONS
CHIRAL SYMMETRY
CORRELATIONS
DELTA-1236 RESONANCES
DENSITY
ELEMENTARY PARTICLES
EQUATIONS
EQUATIONS OF STATE
FERMIONS
HADRONS
MATHEMATICAL MODELS
MATTER
MESONS
N)RESONANCES
NEUTRON STARS
NUCLEAR MATTER
NUCLEON-NUCLEON POTENTIAL
PARTICLE MODELS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PIONS
PSEUDOSCALAR MESONS
RESONANCE PARTICLES
SIGMA MODEL
STARS
SYMMETRY