Isospin-dependent pion in-medium effects on the charged-pion ratio in heavy ion collisions

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.81.024910· OSTI ID:21386627

Jun, Xu ^[1]; Ko, Che Ming ^[2]; Oh, Yongseok ^[3]

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1. Cyclotron Institute, Texas A and M University, College Station, Texas 77843 (United States)
2. Cyclotron Institute and Department of Physics and Astronomy, Texas A and M University, College Station, Texas 77843 (United States)
3. Korea Institute of Science and Technology Information, Daejeon 305-806 (Korea, Republic of)

Using results from the chiral perturbation theory for the s-wave interaction and the {Delta}-resonance model for the p-wave interaction of pions with nucleons, we evaluated the spectral functions of pions in asymmetric nuclear matter with unequal proton and neutron densities. We find that in hot dense neutron-rich matter the strength of the spectral function of positively charged pions at low energies is somewhat larger than that of negatively charged pions. In a thermal model, this isospin-dependent effect slightly reduces the ratio of negatively charged to positively charged pions that are produced in heavy ion collisions induced by radioactive beams. The relevance of our results to the determination of the nuclear symmetry energy from the measured ratio of negatively to positively charged pions produced in heavy ion collisions is discussed.

• OSTI ID: 21386627
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 81, Issue 2; Other Information: DOI: 10.1103/PhysRevC.81.024910; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
BEAMS
CHIRALITY
HEAVY ION REACTIONS
INTERACTIONS
ISOSPIN
NEUTRON DENSITY
NEUTRONS
NUCLEAR MATTER
P WAVES
PERTURBATION THEORY
PION-NUCLEON INTERACTIONS
PIONS
PROTONS
RESONANCE
S WAVES
SPECTRAL FUNCTIONS
SYMMETRY
BARYONS
BOSONS
ELEMENTARY PARTICLES
FERMIONS
FUNCTIONS
HADRON-HADRON INTERACTIONS
HADRONS
MATTER
MESON-BARYON INTERACTIONS
MESON-NUCLEON INTERACTIONS
MESONS
NUCLEAR REACTIONS
NUCLEONS
PARTIAL WAVES
PARTICLE INTERACTIONS
PARTICLE PROPERTIES
PSEUDOSCALAR MESONS