7 research outputs found
Dark Matter through the Axion Portal
Motivated by the galactic positron excess seen by PAMELA and ATIC/PPB-BETS,
we propose that dark matter is a TeV-scale particle that annihilates into a
pseudoscalar "axion." The positron excess and the absence of an anti-proton or
gamma ray excess constrain the axion mass and branching ratios. In the simplest
realization, the axion is associated with a Peccei-Quinn symmetry, in which
case it has a mass around 360-800 MeV and decays into muons. We present a
simple and predictive supersymmetric model implementing this scenario, where
both the Higgsino and dark matter obtain masses from the same source of
TeV-scale spontaneous symmetry breaking.Comment: 5 pages; reference adde
The Tokyo Axion Helioscope Experiment
A preliminary result of the solar axion search experiment at the University
of Tokyo is presented. We searched for axions which could be produced in the
solar core by exploiting the axion helioscope. The helioscope consists of a
superconducting magnet with field strength of 4 Tesla over 2.3 meters. From the
absence of the axion signal we set a 95 % confidence level upper limit on the
axion coupling to two photons for the axion mass eV. This is the first solar axion
search experiment whose sensitivity to exceeds the limit
inferred from the solar age consideration.Comment: 5 pages, 5 eps files included, uses espcrc2.sty, to be published in
Proc. AXION WORKSHOP, Gainesville, Florida, 13-15 March 1998, ed. by
P.Sikivi
Proposal to search for a monochromatic component of solar axions using Fe
An experimental method is introduced to search for almost monochromatic solar
axions. In this method, we can search for solar axions by exploiting the
axion-quark coupling, not relying on the axion-photon coupling at all. A recent
experimental result of Kr\v cmar is presented.Comment: 4 pages, 2 eps figures included, uses espcrc2.sty, to be published in
Proc. AXION WORKSHOP, Gainesville, Florida, 13-15 March 1998, ed. by
P.Sikivi
QCD Sum Rules and Applications to Nuclear Physics
Applications of QCD sum-rule methods to the physics of nuclei are reviewed,
with an emphasis on calculations of baryon self-energies in infinite nuclear
matter. The sum-rule approach relates spectral properties of hadrons
propagating in the finite-density medium, such as optical potentials for
quasinucleons, to matrix elements of QCD composite operators (condensates). The
vacuum formalism for QCD sum rules is generalized to finite density, and the
strategy and implementation of the approach is discussed. Predictions for
baryon self-energies are compared to those suggested by relativistic nuclear
physics phenomenology. Sum rules for vector mesons in dense nuclear matter are
also considered.Comment: 92 pages, ReVTeX, 9 figures can be obtained upon request (to Xuemin
Jin