11,696 research outputs found
A New Solution of the Solar Neutrino Flux
We report a new solution to explain the observed deficit of the solar
neutrino flux by Homestake, Kamiokande II and III, GALLEX and SAGE experiments.
We use the matter mixing and the helicity oscillation in the twisting magnetic
fields in the sun. Our model predicts the short (seasonal) and long (11 years)
time variations of the solar neutrino flux. Three kinds of data observed by
Homestake, Kamiokande, GALLEX and SAGE detectors are reproduced well if the
mixing angle and the squared mass difference are in the small area around
and .Comment: 13 pages and 4 figures (not included), in phyzzx, OU-HET-19
Supersymmetry of M-Branes at Angles
We determine the possible fractions of supersymmetry preserved by two
intersecting M-5-branes. These include the fractions 3/32 and 5/32 which have
not occurred previously in intersecting brane configurations. Both occur in
non-orthogonal pointlike intersections of M-5-branes but 5/32 supersymmetry is
possible only for specific fixed angles.Comment: 11 pages, Late
A BCS-BEC crossover in the extended Falicov-Kimball model: Variational cluster approach
We study the spontaneous symmetry breaking of the excitonic insulator state
induced by the Coulomb interaction in the two-dimensional extended
Falicov-Kimball model. Using the variational cluster approximation (VCA) and
Hartree-Fock approximation (HFA), we evaluate the order parameter,
single-particle excitation gap, momentum distribution functions, coherence
length of excitons, and single-particle and anomalous excitation spectra, as a
function of at zero temperature. We find that in the weak-to-intermediate
coupling regime, the Fermi surface plays an essential role and calculated
results can be understood in close correspondence with the BCS theory, whereas
in the strong-coupling regime, the Fermi surface plays no role and results are
consistent with the picture of BEC. Moreover, we find that HFA works well both
in the weak- and strong-coupling regime, and that the difference between the
results of VCA and HFA mostly appears in the intermediate-coupling regime. The
reason for this is discussed from a viewpoint of the self-energy. We thereby
clarify the excitonic insulator state that typifies either a BCS condensate of
electron-hole pairs (weak-coupling regime) or a Bose-Einstein condensate of
preformed excitons (strong-coupling regime).Comment: 11 pages, 9 figure
CO(J=6-5) Observations of the Quasar SDSS1044-0125 at z = 5.8
We present a result of the quasar CO(J=6-5) observations of SDSSp
J104433.04-012502.2 at z = 5.8. Ten-days observations with the Nobeyama
Millimeter Array yielded an rms noise level of ~ 2.1 mJy/beam in a frequency
range from 101.28 GHz to 101.99 GHz at a velocity resolution of 120 km/s. No
significant clear emission line was detected in the observed field and
frequency range. Three sigma upper limit on the CO(J=6-5) luminosity of the
object is 2.8 x 10^10 K km/s pc^2, corresponding to a molecular gas mass of 1.2
x 10^11 Solar Mass, if a conversion factor of 4.5 Solar Mass /(K km/s pc^2) is
adopted. The obtained upper limit on CO luminosity is slightly smaller than
those observed in quasars at z=4-5 toward which CO emissions are detected.Comment: 4 pages, 3 figures, LaTeX2e, to appear in Publication of Astronomical
Society of Japan (PASJ), Postscript file available at
ftp://ftp.kusastro.kyoto-u.ac.jp/pub/iwata/preprint/sdss1044/sdss.ps.g
- …