361 research outputs found

    Gravity in Dynamically Generated Dimensions

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    A theory of gravity in d+1d+1 dimensions is dynamically generated from a theory in dd dimensions. As an application we show how NN dynamically coupled gravity theories can reduce the effective Planck mass.Comment: 7 pages, LaTeX (Revtex

    Unparticles: Scales and High Energy Probes

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    Unparticles from hidden conformal sectors provide qualitatively new possibilities for physics beyond the standard model. In the theoretical framework of minimal models, we clarify the relation between energy scales entering various phenomenological analyses. We show that these relations always counteract the effective field theory intuition that higher dimension operators are more highly suppressed, and that the requirement of a significant conformal window places strong constraints on possible unparticle signals. With these considerations in mind, we examine some of the most robust and sensitive probes and explore novel effects of unparticles on gauge coupling evolution and fermion production at high energy colliders. These constraints are presented both as bounds on four-fermion interaction scales and as constraints on the fundamental parameter space of minimal models.Comment: 16 pages, 2 tables, 6 figures; reference added, published versio

    The Role of BsKπB_s \to K \pi in Determining the Weak Phase γ\gamma

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    The decay rates for B0K+πB^0 \to K^+ \pi^-, B+K0π+B^+ \to K^0 \pi^+, and the charge-conjugate processes were found to provide information on the weak phase γArg(Vub)\gamma \equiv {\rm Arg}(V_{ub}^*) when the ratio rr of weak tree and penguin amplitudes was taken from data on BππB \to \pi \pi or semileptonic BπB \to \pi decays. We show here that the rates for BsKπ+B_s \to K^- \pi^+ and BˉsK+π\bar B_s \to K^+ \pi^- can provide the necessary information on rr, and estimate the statistical accuracy of forthcoming measurements at the Fermilab Tevatron.Comment: 8 pages, LaTeX, no figures, submitted to Physics Letters B, corrections to discussion of SU(3) breaking adde

    Discrete quantum gravity in the framework of Regge calculus formalism

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    An approach to the discrete quantum gravity based on the Regge calculus is discussed which was developed in a number of our papers. Regge calculus is general relativity for the subclass of general Riemannian manifolds called piecewise flat ones. Regge calculus deals with the discrete set of variables, triangulation lengths, and contains continuous general relativity as a particular limiting case when the lengths tend to zero. In our approach the quantum length expectations are nonzero and of the order of Plank scale 1033cm10^{-33}cm. This means the discrete spacetime structure on these scales.Comment: LaTeX, 16 pages, to appear in JET

    Regge calculus in the canonical form

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    (3+1) (continuous time) Regge calculus is reduced to Hamiltonian form. The constraints are classified, classical and quantum consequences are discussed. As basic variables connection matrices and antisymmetric area tensors are used supplemented with appropriate bilinear constraints. In these variables the action can be made quasipolinomial with arcsin\arcsin as the only deviation from polinomiality. In comparison with analogous formalism in the continuum theory classification of constraints changes: some of them disappear, the part of I class constraints including Hamiltonian one become II class (and vice versa, some new constraints arise and some II class constraints become I class). As a result, the number of the degrees of freedom coincides with the number of links in 3-dimensional leaf of foliation. Moreover, in empty space classical dynamics is trivial: the scale of timelike links become zero and spacelike links are constant.Comment: 24 pages,Plain LaTeX,BINP 93-4

    Desperately Seeking Non-Standard Phases via Direct CP Violation in bsgb\to sg^\ast Process

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    Attributing the recent CLEO discovery of Bη+XsB \to \eta' + X_s to originate (primarily) from the fragmentation of an off-shell gluon (gg^*) via bs+gb \to s + g^*, gg+ηg^* \to g + \eta', we emphasize that many such states (XgX_g) should materialize. Indeed the hadronic fragments (XgX_g) of gg^* states are closely related to those seen in ψγ(ϕ,ω)+Xg\psi \to \gamma (\phi, \omega) + X_g. A particular final state of considerable interest is Xg=K+KX_g=K^+K^-. Signals from such states in BB decays can be combined to provide a very sensitive search for CP violating phase(s) from non-standard physics. The method should work even if the contribution of these source(s) to the rates is rather small (10\sim10%) to the point that a comparison between theory and experiment may find it extremely difficult to reveal the presence of such a new physics.Comment: 16 pages, 5 figure

    Coherent States and N Dimensional Coordinate Noncommutativity

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    Considering coordinates as operators whose measured values are expectations between generalized coherent states based on the group SO(N,1) leads to coordinate noncommutativity together with full NN dimensional rotation invariance. Through the introduction of a gauge potential this theory can additionally be made invariant under NN dimensional translations. Fluctuations in coordinate measurements are determined by two scales. For small distances these fluctuations are fixed at the noncommutativity parameter while for larger distances they are proportional to the distance itself divided by a {\em very} large number. Limits on this number will lbe available from LIGO measurements.Comment: 16 pqges. LaTeX with JHEP.cl

    Expanding Cosmologies in Brane Geometries

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    Five dimensional gravity coupled, both in the bulk and on a brane, to a scalar Liouville field yields a geometry confined to a strip around the brane and with time dependent scale factors for the four geometry. In various limits known models can be recovered as well as a temporally expanding four geometry with a warp factor falling exponentially away from the brane. The effective theory on the brane has a time dependent Planck mass and ``cosmological constant''. Although the scale factor expands, the expansion is not an acceleration.Comment: 7 pages, LaTex/RevTex

    Brane World Cosmology In Jordan-Brans-Dicke Theory

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    We consider the embedding of 3+1 dimensional cosmology in 4+1 dimensional Jordan-Brans-Dicke theory. We show that exponentially growing and power law scale factors are implied. Whereas the 4+1 dimensional scalar field is approximately constant for each, the effective 3+1 dimensional scalar field is constant for exponentially growing scale factor and time dependent for power law scale factor.Comment: 11 page
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