13 research outputs found
Applicability of Heavy Quark Effective Theory to the Radiative Decay
In the context of the observed decay the
applicability of the Heavy Quark Effective Theory (HQET), treating both b and s
as heavy quarks, is examined. We show that the heavy s-quark approximation, as
can be found in the literature, is not reliable.Comment: Plain LaTeX fil
Symmetry Breaking for Rho Meson in Neutron Matter
Qualitative changes in the collective excitation spectra of the -meson
triplet in neutron matter is studied, with particular emphasis on the breaking
of the discrete symmetry. The appearance of additional
branches in the dispersion characteristics, the mass splitting among the charge
states, the splitting between longitudinal and transverse modes of the
mesons and the appearance of `island' modes (or loops) in the
time-like region are some of the features that are exposed.Comment: Plain LaTeX fil
Tensor Coupling and Vector Mesons in Dense Nuclear Matter
The effects of magnetic interaction between vector mesons and nucleons on the
propagation (mass and width) of the -meson in particular moving through
very dense nuclear matter is studied and the modifications, qualitative and
quantitative, due to the relevant collective modes (zero-sound and plasma
frequencies) of the medium discussed. It is shown that the -mesons
produced in high-energy nuclear collisions will be longitudinally polarized in
the region of sufficiently dense nuclear matter, in the presence of such an
interaction.Comment: Plain Latex file. Three figures, not appended, may be obtained on
request to [email protected]
Radiative Corrections to \zbb from Colored Scalars in a Model with Dynamical Symmetry Breaking
Isodoublet color-octet scalar bosons appear in the low-energy limit of a
natural extension of the Standard Model in which the electroweak symmetry is
broken by a condensate. We briefly discuss the model and show that
radiative corrections (involving these scalars) to the branching ratio
are
negative and thus place a stringent lower bound on the masses of the colored
scalars. This turns out to be GeV with GeV and increases
quadratically with . It is emphasized that is a parameter that is
well-determined experimentally and that theoretical estimates are relatively
free from uncertainties emanating from hadronic corrections and are
comparatively insensitive to the value of the top mass.Comment: 9 pages + 3 figures (available upon request), TeX file. Saha
Institute Preprint no. SINP-TNP/93-22 (December 1993
Dispersive Bounds on The Shape Of Lambda_b to Lambda_c l {\bar \nu_l} Formfactors
We derive a theoretically allowed domain for the charge radius and
curvature of the Isgur-Wise function describing the decay . Our method uses crossing symmetry, dispersion
relations and analyticity in the context of the Heavy Quark Effective Theory
but is independent of the specifics of any given model. The experimentally
determined values of the masses have been used as input information.
The results are of interest for testing different models employed to calculate
the heavy baryon formfactors which are used for the extraction of
from the experimental data.Comment: 18 pages, 1 figure included via psfi