5,552 research outputs found
Forbidden Line Emission in the Eccentric Spectroscopic Binaries DQ Tauri and UZ Tauri E Monitored over an Orbital Period
We present echelle spectroscopy of the close pre-main-sequence binary star
systems DQ Tau and UZ Tau-E. Over a 16 day time interval we acquired 14 nights
of spectra for DQ Tau and 12 nights of spectra for UZ Tau-E. This represents
the entire phase of DQ Tau, and 63 percent of the phase of UZ Tau-E. As
expected, photospheric lines such as Li I 6707 clearly split into two
components as the primary and secondary orbit one another, as did the permitted
line He I 5876. Unlike the photospheric features, the forbidden lines of [O I]
6300 and [O I] 5577, retain the same shape throughout the orbit. Therefore
these lines must originate outside of the immediate vicinity of the two stars
and any circumstellar disks that participate in the orbital motion of the
stars.Comment: 14 pages including 6 figures, aastex preprint, accepted to
Astronomical Journa
Sea Contributions to Spin 1/2 Baryon Structure, Magnetic Moments, and Spin Distribution
We treat the baryon as a composite system made out of a \lq\lq core" of three
quarks (as in the standard quark model) surrounded by a \lq\lq sea" (of gluons
and -pairs) which is specified by its total quantum numbers like
flavor, spin and color. Specifically, we assume the sea to be a flavor octet
with spin 0 or 1 but no color. The general wavefunction for spin 1/2 baryons
with such a sea component is given. Application to the magnetic moments is
considered. Numerical analysis shows that a scalar (spin 0) sea with an
admixture of a vector (spin 1) sea can provide very good fits to the magnetic
moment data {\em using experimental errors}. Our best fit automatically gives
for neutron beta decay in agreement with data. This fit also gives
reasonable values for the spin distributions of the proton and neutron.Comment: 24 pages, REVTEX. References modifie
A priori mixed hadrons, hyperon non-leptonic decays, and the |\Delta I|=1/2 rule
The |\Delta I|=1/2 rule in non-leptonic decays of hyperons can be naturally
understood by postulating a priori mixed physical hadrons, along with the
isospin invariance of the responsible transition operator. It is shown that
this operator can be identified with the strong interaction Yukawa hamiltonian.Comment: Workshops on Particles and Fields and Phenomenology of Fundamental
Interactions. J. C. D'Olivo, A. Fernandez, and M. A. Perez, Ed
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