967 research outputs found

    Baryons and Mesons with Beauty

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    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

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    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 U(1)×U(1)U(1)\times U(1) gauge plus Z2\mathbb{Z}_2 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

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    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 Gcts⊗GdiscreteG_{\text{cts}} \otimes G_{\text{discrete}} symmetry is spontaneously broken to Hcts⊗HdiscreteH_{\text{cts}} \otimes H_{\text{discrete}}, where the continuous subgroup HctsH_{\text{cts}} can be embedded in several different ways in the parent group GctsG_{\text{cts}}, and Hdiscrete<GdiscreteH_{\text{discrete}} < G_{\text{discrete}}. A certain class of topological domain wall solutions connect two vacua that are invariant under {\it differently embedded} HctsH_{\text{cts}} 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 HctsH_{\text{cts}} 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 I−I-, U−U- and V−V-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 E6E_6 is discussed.Comment: 30 pages, 9 embedded figure

    Black Reaction to Segregation and Discrimination in Post-Reconstruction

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    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

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    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 k2(ϕ)∂μϕ∂μϕk^2(\phi)\partial^\mu \phi \partial_\mu \phi 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

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    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 ww. 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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