When the atomic nucleus is probed in experiments that involve large momentum transfers, one often observes unusual phenomena indicating that the nucleus is more than a simple aggregate of protons and neutrons, i.e., the nucleus has non-nucleonic degrees of freedom. Guided by the chiral symmetry requirements of strong interactions, we are investigating when and how effective meson degrees of freedom of the nucleus (exchange currents) can be observed.
During a supernova explosion nuclear matter is compressed to high densities (tightly packed protons and neutrons). From reasonable theoretical extrapolations it is expected that a strange meson condensate can form at these high nuclear densities. We are examining the dynamics leading to a possible formation of a meson condensate. Since nucleons consist of confined quarks, another question of importance at high nuclear densities is how and under what conditions these quark degrees of freedom affect nuclear observables.
Antimatter interactions with matter is a violent process. Symmetry arguments indicates that the long range forces between two nucleons imply attactive long range nucleon-antinucleon forces. However, at short nucleon antinucleon distances the annihilation process dominates. The annihilation process converts mass to energy and is closely connected to the quark and antiquark structure of the nucleon and antinucleon. This matter-antimatter annihilation process produces a large number of energetic mesons. We investigate the annihilation process making use of effective theories and phenomenological quark models.
For further information see Nuclear Theory or Experimental Nuclear Physics. or Publications
Research Associate 1973-75, Swiss
Institute Nuclear Physics (PSI), Villigen, Switzerland;
Senior Fellow
1975-77, CERN, Geneva, Switzerland;
Assistant Professor: 1977-81, NORDITA, Copenhagen,
Denmark;
Associate Professor: 1981-84, Univ. South
Carolina;
Professor:
1984-present, Univ. South Carolina.
Sabbatical leave: (Acad.Year
1988/1989) at M.I.T., Cambridge, MA; USA
Visiting Professor:
(April-August 1994)
at NORDITA, Copenhagen, Denmark.
"The Nucleon-Nucleon Force and the Quark Degrees of Freedom,"
F. Myhrer and J. Wroldsen, Review of Modern Physics, 60
629 (1988).
"The Chiral Quark Bag; Properties and Spectroscopy of baryons and the Nuclear Force",
F. Myhrer, in Quarks and Nuclei,
Int. Review Nucl. Phys. Vol.1,
ed. W. Weise (World Scientific Publ. Co., Singapore) pp.325-407 (1984).
Some "Recent" Publications:
I can be reached via email at myhrer@sc.edu. Return to:Physics & Astronomy Homepage.