967 research outputs found
Baryons and Mesons with Beauty
Recent experimental findings of several mesons and baryons with "beauty" and
"charm" as flavors remind us of the days when strangeness was discovered, and
how its inclusion led to SU(3)-flavor symmetry with enormous success in the
classification of the "proliferated" states into SU(3) multiplets. One of the
key elements was the successful application of the first order perturbation in
symmetry breaking, albeit what then appeared to be huge mass differences, and
the prediction of new states that were confirmed by experiments. In this note,
we venture into the past and, applying the same techniques, predict some new
"beauty-" and "charm-" flavored hadrons. If these new states are confirmed
experimentally, it may provide a useful phenomenological model for classifying
numerous states that are found to be in the PDG data and could invite further
theoretical challenges towards our understanding of symmetry breaking.Comment: 9 pages, 5 figures, plain Late
Domain wall solutions with Abelian gauge fields
We study kink (domain wall) solutions in a model consisting of two complex
scalar fields coupled to two independent Abelian gauge fields in a Lagrangian
that has gauge plus discrete symmetry. We find
consistent solutions such that while the U(1) symmetries of the fields are
preserved while in their respective vacua, they are broken on the domain wall.
The gauge field solutions show that the domain wall is sandwiched between
domains with constant magnetic fields.Comment: 11 pages, 6 figures, JHEP for style, but to appear in PLB. Added
discussion about the boundary conditions and the physical picture based on
superconductivity. Reference adde
Clash of symmetries on the brane
If our 3+1-dimensional universe is a brane or domain wall embedded in a
higher dimensional space, then a phenomenon we term the ``clash of symmetries''
provides a new method of breaking some continuous symmetries. A global
symmetry is spontaneously broken
to , where the continuous subgroup
can be embedded in several different ways in the parent group
, and . A certain
class of topological domain wall solutions connect two vacua that are invariant
under {\it differently embedded} subgroups. There is then
enhanced symmetry breakdown to the intersection of these two subgroups on the
domain wall. This is the ``clash''. In the brane limit, we obtain a
configuration with symmetries in the bulk but the smaller
intersection symmetry on the brane itself. We illustrate this idea using a
permutation symmetric three-Higgs-triplet toy model exploiting the distinct
, and spin U(2) subgroups of U(3). The three disconnected portions
of the vacuum manifold can be treated symmetrically through the construction of
a three-fold planar domain wall junction configuration, with our universe at
the nexus. A possible connection with is discussed.Comment: 30 pages, 9 embedded figure
Black Reaction to Segregation and Discrimination in Post-Reconstruction
Equality of protection under the laws, as guaranteed by the Fourteenth Amendment to the United States Constitution, implies that in the administration of criminal justice no person, by reason of his race or color, shall be subjected for the same offense to any greater or different punishment than that to which persons of another race or color are subjected. It also suggests that all citizens are entitled to protection of their civil rights and against discriminatory practices based upon race, color, creed, or religion. Unfortunately, in October 1883 when the United States Supreme Court declared the Civil Rights Acts of 1875 unconstitutional, the legislative framework requiring states to provide for civil rights in public places of accommodation and transportation was dismantled. It further had the effect of nullifying the civil rights act passed by Florida lawmakers in 1873
Evading Lyth bound in models of quintessential inflation
Quintessential inflation refers to an attempt to unify inflation and
late-time cosmic acceleration using a single scalar field. In this letter we
consider two different classes of quintessential inflation, one of which is
based upon a Lagrangian with non-canonical kinetic term and a steep exponential potential while the second
class uses the concept of steep brane world inflation. We show that in both
cases the Lyth bound can be evaded, despite the large tensor-to-scalar ratio of
perturbations. The post-inflationary dynamics is consistent with
nucleosynthesis constraint in these cases.Comment: 6 Latex pages, no figures, reference updated and typos corrected, To
appear in PL
The clash of symmetries in a Randall-Sundrum-like spacetime
We present a toy model that exhibits clash-of-symmetries style Higgs field
kink configurations in a Randall-Sundrum-like spacetime. The model has two
complex scalar fields Phi_{1,2}, with a sextic potential obeying global
U(1)xU(1) and discrete Phi_1 Phi_2 interchange symmetries. The scalar
fields are coupled to 4+1 dimensional gravity endowed with a bulk cosmological
constant. We show that the coupled Einstein-Higgs field equations have an
interesting analytic solution provided the sextic potential adopts a particular
form. The 4+1 metric is shown to be that of a smoothed-out Randall-Sundrum type
of spacetime. The thin-brane Randall-Sundrum limit, whereby the Higgs field
kinks become step functions, is carefully defined in terms of the fundamental
parameters in the action. The ``clash of symmetries'' feature, defined in
previous papers, is manifested here through the fact that both of the U(1)
symmetries are spontaneously broken at all non-asymptotic points in the extra
dimension . One of the U(1)'s is asymptotically restored as w --> -infinity,
with the other U(1) restored as w --> +infinity. The spontaneously broken
discrete symmetry ensures topological stability. In the gauged version of this
model we find new flat-space solutions, but in the warped metric case we have
been unable to find any solutions with nonzero gauge fields.Comment: 15 pages, 5 figures; minor changes including added references and an
updated figure; to appear in Phys Rev
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