4 research outputs found
Discovery of naked charm particles and lifetime differences among charm species using nuclear emulsion techniques innovated in Japan
This is a historical review of the discovery of naked charm particles and lifetime differences among charm species. These discoveries in the field of cosmic-ray physics were made by the innovation of nuclear emulsion techniques in Japan. A pair of naked charm particles was discovered in 1971 in a cosmic-ray interaction, three years prior to the discovery of the hidden charm particle, J/Ψ, in western countries. Lifetime differences between charged and neutral charm particles were pointed out in 1975, which were later re-confirmed by the collaborative Experiment E531 at Fermilab. Japanese physicists led by K.Niu made essential contributions to it with improved emulsion techniques, complemented by electronic detectors. This review also discusses the discovery of artificially produced naked charm particles by us in an accelerator experiment at Fermilab in 1975 and of multiple-pair productions of charm particles in a single interaction in 1987 by the collaborative Experiment WA75 at CERN
In-medium nuclear interactions of low-energy hadrons
Experimental and theoretical developments of the last decade in the study of
exotic atoms and some related low-energy reactions are reviewed, in order to
provide information on the in-medium hadron-nucleon t matrix over a wide range
of densities up to central nuclear densities. In particular, we review pionic
deeply bound atomic states and related evidence for partial restoration of
chiral symmetry in dense nuclear matter. The case for relatively narrow deeply
bound atomic states for antikaons and antiprotons is made, based on the physics
of strong nuclear absorption. Recent experimental suggestions for signals of
antikaon-nuclear deeply bound states are reviewed, and dynamical models for
calculating binding energies, widths and densities of antikaon nuclear states
are discussed. Specific features of low-energy in-medium interactions of kaons,
antiprotons and of Sigma hyperons are discussed, and suggestions to study
experimentally Cascade atoms are reviewed.Comment: 86 pages, 44 figures, slight revisions, references added, Physics
Reports (in press
Electrodynamics of Correlated Electron Materials
We review studies of the electromagnetic response of various classes of
correlated electron materials including transition metal oxides, organic and
molecular conductors, intermetallic compounds with - and -electrons as
well as magnetic semiconductors. Optical inquiry into correlations in all these
diverse systems is enabled by experimental access to the fundamental
characteristics of an ensemble of electrons including their self-energy and
kinetic energy. Steady-state spectroscopy carried out over a broad range of
frequencies from microwaves to UV light and fast optics time-resolved
techniques provide complimentary prospectives on correlations. Because the
theoretical understanding of strong correlations is still evolving, the review
is focused on the analysis of the universal trends that are emerging out of a
large body of experimental data augmented where possible with insights from
numerical studies.Comment: 78 pages, 55 figures, 984 reference