1,415 research outputs found

    Baryons and Mesons with Beauty

    Get PDF
    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

    Observed galaxy power spectrum in cubic Galileon model

    Full text link
    In this paper, we study the effects of general relativistic corrections on the observed galaxy power spectrum in thawing class of cubic Galileon model with linear potential that preserves the shift symmetry. In this scenario, the observed galaxy power spectrum differs from the standard matter power spectrum mainly due to redshift space distortion (RSD) factor and relativistic effects. The RSD term enhances the matter power spectrum both at larger and smaller scales whereas the relativistic terms further enhance the matter power spectrum only at larger scales. In comparison with Λ\LambdaCDM, the observed galaxy power spectrum is always suppressed at large scales in this scenario although this suppression is always small compared to the canonical quintessence scenario.Comment: 14 pages, LaTeX style, 7 figures, Comments are welcom

    Clash of symmetries on the brane

    Get PDF
    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 GctsGdiscreteG_{\text{cts}} \otimes G_{\text{discrete}} symmetry is spontaneously broken to HctsHdiscreteH_{\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 II-, UU- and VV-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

    The clash of symmetries in a Randall-Sundrum-like spacetime

    Get PDF
    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

    Quintessential inflation with canonical and noncanonical scalar fields and Planck 2015 results

    Full text link
    We investigate two classes of models of quintessential inflation, based upon canonical as well as noncanonical scalar fields. In particular, introducing potentials steeper than the standard exponential, we construct models that can give rise to a successful inflationary phase, with signatures consistent with Planck 2015 results. Additionally, using nonminimal coupling of the scalar field with massive neutrino matter, we obtain the standard thermal history of the Universe, with late-time cosmic acceleration as the last stage of evolution. In both cases, inflation and late-time acceleration are connected by a tracker solution.Comment: 13 pages, 18 figures, minor clarifications added and refs updated, to appear in PR

    The Inter-Mammary Sticky Roll: A Novel Technique for Securing a Doppler Ultrasonic Probe to the Precordium for Venous Air Embolism Detection.

    Get PDF
    Venous air embolism is a devastating and potentially life-threatening complication that can occur during neurosurgical procedures. We report the development and use of the "inter-mammary sticky roll," a technique to reliably secure a precordial Doppler ultrasonic probe to the chest wall during neurosurgical cases that require lateral decubitus positioning. We have found that this noninvasive technique is safe, and effectively facilitates a constant Doppler signal with no additional risk to the patient

    Light-Heavy Symmetry: Geometric Mass Hierarchy for Three Families

    Get PDF
    The Universal Seesaw pattern coupled with a Light\leftrightarrowHeavy symmetry principle leads to the Diophantine equation N=i=1Nni\displaystyle N = \sum_{i=1}^Nn_i, where ni0n_i\geq 0 and distinct. Its unique non-trivial solution (3=0+1+2)(3=0+1+2) gives rise to the geometric mass hierarchy mWm_W, mWϵm_W\epsilon, mWϵ2m_W\epsilon^2 for N=3N=3 fermion families. This is realized in a model where the hybrid (yet Up\leftrightarrowDown symmetric) quark mass relations mdmtmc2mumbms2m_d m_t \approx m_c^2\leftrightarrow m_u m_b \approx m_s^2 play a crucial role in expressing the CKM mixings in terms of simple mass ratios, notably sinθCmcmb\sin\theta_C \approx {m_c\over m_b}.Comment: 12 pages, no figures, Revtex fil

    SU(5) grand unification on a domain-wall brane from an E_6-invariant action

    Get PDF
    An SU(5) grand unification scheme for effective 3+1-dimensional fields dynamically localised on a domain-wall brane is constructed. This is achieved through the confluence of the clash-of-symmetries mechanism for symmetry breaking through domain-wall formation, and the Dvali-Shifman gauge-boson localisation idea. It requires an E_6 gauge-invariant action, yielding a domain-wall solution that has E_6 broken to differently embedded SO(10) x U(1) subgroups in the two bulk regions on opposite sides of the wall. On the wall itself, the unbroken symmetry is the intersection of the two bulk subgroups, and contains SU(5). A 4+1-dimensional fermion family in the 27 of E_6 gives rise to localised left-handed zero-modes in the 5^* + 10 + 1 + 1 representation of SU(5). The remaining ten fermion components of the 27 are delocalised exotic states, not appearing in the effective 3+1-dimensional theory on the domain-wall brane. The scheme is compatible with the type-2 Randall-Sundrum mechanism for graviton localisation; the single extra dimension is infinite.Comment: 21 pages, 9 figures. Minor changes to text and references. To appear in Phys. Rev.
    corecore