2,911 research outputs found
MSW mediated neutrino decay and the solar neutrino problem
We investigate the solar neutrino problem assuming simultaneous presence of
MSW transitions in the sun and neutrino decay on the way from sun to earth. We
do a global -analysis of the data on total rates in Cl, Ga and
Superkamiokande (SK) experiments and the SK day-night spectrum data and
determine the changes in the allowed region in the \dm - \tan^2\theta plane
in presence of decay. We also discuss the implications for unstable neutrinos
in the SNO experiment.Comment: Final version to appear in Phys. Rev.
Spectroscopic investigation of unstudied southern PNe
We present a spectroscopic investigation of two hitherto unstudied galactic
planetary nebulae (MeWe 1-10 and MeWe 1-11) and one candidate object (MeWe
2-5). The candidate object clearly has been identified as a bipolar hourglass
shaped PN. The galactic foreground extinction was derived and using
photoionization models with CLOUDY the two round objects were classified as
highly evolved nebulae.Comment: LaTeX, 5 pages with 6 figures, accepted in Astron. & Astrophy
Morpho-kinematic analysis of the point-symmetric, bipolar planetary nebulae Hb 5 and K 3-17, a pathway to poly-polarity
The kinematics of the bipolar planetary nebulae Hb~5 and K 3-17 are
investigated in detail by means of a comprehensive set of spatially resolved
high spectral resolution, long-slit spectra. Both objects share particularly
interesting characteristics, such as a complex filamentary, rosette-type
nucleus, axial point-symmetry and very fast bipolar outflows. The kinematic
information of Hb~5 is combined with {\it HST} imagery to construct a detailed
3D model of the nebula using the code SHAPE. The model shows that the large
scale lobes are growing in a non-homologous way. The filamentary loops in the
core are proven to actually be secondary lobes emerging from what appears to be
a randomly punctured, dense, gaseous core and the material that forms the point
symmetric structure flows within the lobes with a distinct kinematic pattern
and its interaction with the lobes has had a shaping effect on them. Hb~5 and
K~3-17 may represent a class of fast evolving planetary nebulae that will
develop poly-polar characteristics once the nebular core evolves and expands.Comment: 19 pages, 8 figures. To appear in The Astrophysical Journa
The Classification of M1-78
The published properties of M1-78 are discussed with the purpose to resolve
the object's classification as either a planetary nebula or an ultracompact HII
region. A classification as a planetary nebula is rejected primarily because of
the high luminosity of the object, but because of the chemical composition and
expansion velocity of the nebula, a novel classification is proposed instead:
that of an ultracompact HII region with a post-main sequence central star
(possibly a WN star). It must therefore follow that observable ultracompact HII
regions persist beyond the main sequence lifetimes of at least some massive
stars, and so cannot be transient phenomena that are seen only during pre-main
sequence or early main sequence evolution.Comment: 16 pages, Postscrip
Two body non-leptonic decays in quark model with factorization ansatz
The two body non-leptonic decays are analyzed in factorization
approximation, using quark model, as a free parameter. It is
shown that the experimental branching ratio for restricts and this ratio can be understood for a value
of which lies in the range suggested by two body
B meson decays. The branching ratios for are predicted to be larger than the previous estimates. Finally it
is pointed that CKM-Wolfenstein parameter , where is CP
phase, can be determined from the ratio of widths of and or that of
and
independent of the parameter .Comment: 18 pages, latex, 1 figure available on request, please send any
questions or comments to [email protected]
Chargino Production at an e-e- Collider
The chargino pair production in collisions with their subsequent
decays are considered within SUSY models with R-parity violation and with
lepton number non-conservation. The production process ( TeV) is
predicted to be large in a wide range of both sneutrino and chargino masses.
The influence of all virtual sneutrino states and their mixings with electrons
are taken into account. Some specific situations are pointed out when
significant suppressions of the cross section can take place. The chargino
decays are discussed for either the chargino as LSP or the chargino as heavier
sparticle. In both cases unique signals are possible with up to six charged
fermions and without missing energy.Comment: 9 page
K_L \ra \mu^\pm e^\mp \nu \overline{\nu} as background to K_L \ra \mu^\pm e^\mp
We consider the process K_L \ra \mu^\pm e^\mp \nu \overline{\nu} at next to
leading order in chiral perturbation theory. This process occurs in the
standard model at second order in the weak interaction and constitutes a
potential background in searches for new physics through the modes K_L \ra
\mu^\pm e^\mp. We find that the same cut, ~MeV, used to remove
the sequential decays K_{l3}\ra \pi_{l2} pushes the B(K_L \ra \mu^\pm e^\mp
\nu \overline{\nu}) to the level, effectively removing it as a
background.Comment: 8 pages, LaTeX, 1 figure appended as postscript file after
\end{document}. Fermilab-Pub-93/024-
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