The Topology of Branching Universes

The purpose of this paper is to survey the possible topologies of branching space-times, and, in particular, to refute the popular notion in the literature that a branching space-time requires a non-Hausdorff topology

Heavy-Quark Symmetry and the Electromagnetic Decays of Excited Charmed Strange Mesons

Heavy-hadron chiral perturbation theory (HH$\chi$PT) is applied to the decays of the even-parity charmed strange mesons, D_{s0}(2317) and D_{s1}(2460). Heavy-quark spin symmetry predicts the branching fractions for the three electromagnetic decays of these states to the ground states D_s and D_s^* in terms of a single parameter. The resulting predictions for two of the branching fractions are significantly higher than current upper limits from the CLEO experiment. Leading corrections to the branching ratios from chiral loop diagrams and spin-symmetry violating operators in the HH$\chi$PT Lagrangian can naturally account for this discrepancy. Finally the proposal that the D_{s0}(2317) (D_{s1}(2460)) is a hadronic bound state of a D (D^*) meson and a kaon is considered. Leading order predictions for electromagnetic branching ratios in this molecular scenario are in very poor agreement with existing data.Comment: 25 pages, 3 figure

Graph duality as an instrument of Gauge-String correspondence

We explore an identity between two branching graphs and propose a physical meaning in the context of the gauge-gravity correspondence. From the mathematical point of view, the identity equates probabilities associated with $\mathbb{GT}$, the branching graph of the unitary groups, with probabilities associated with $\mathbb{Y}$, the branching graph of the symmetric groups. In order to furnish the identity with physical meaning, we exactly reproduce these probabilities as the square of three point functions involving certain hook-shaped backgrounds. We study these backgrounds in the context of LLM geometries and discover that they are domain walls interpolating two AdS spaces with different radii. We also find that, in certain cases, the probabilities match the eigenvalues of some observables, the embedding chain charges. We finally discuss a holographic interpretation of the mathematical identity through our results.Comment: 34 pages. version published in journa

Properties of the DsJ states

Recent measurements involving the newly discovered D_sJ particles are reported. The results of D_sJ production and decay branching fraction measurements are shown. Possible spin-parity and quark content assignments of D_sJ mesons are discussed. The results are based on a large data sample recorded by the Belle detector at the KEKB e^+ e^- collider.Comment: 4 pages, 3 figures, proceedings to the talk given on behalf of the Belle Collaboration at the First Meeting of the APS Topical Group on Hadron Physic

New developments in measurements of CP violation

We present several alternative techniques used by the BaBar Collaboration in order to measure the Unitarity Triangle angle gamma. We also present the results of two searches designed to improve the measurements of sin(2beta) using penguin B decay modes by reducing the hadronic corrections uncertainties.Comment: 6 pages, 4 figures, Contribution to Moriond ElectroWeak 2006 Proceeding

Branching Ratios for B→K∗γB \to K^* \gamma and B→ργB \to \rho \gamma Decays in Next-to-Leading Order in the Large Eneregy Effective Theory

We calculate the so-called hard spectator corrections in ${\cal O} (\alpha_s)$ in the leading-twist approximation to the decay widths for $B \to K^{*} \gamma$ and $B \to \rho \gamma$ decays and their charge conjugates, using the Large Energy Effective Theory (LEET) techniques. Combined with the hard vertex and annihilation contributions, they are used to compute the branching ratios for these decays in the next-to-leading order (NLO) in the strong coupling $\alpha_s$ and in leading power in $\Lambda_{\rm QCD}/M_B$. These corrections are found to be large, leading to the inference that the theoretical branching ratios for the decays $B \to K^* \gamma$ in the LEET approach can be reconciled with current data only for significantly lower values of the form factors than their estimates in the QCD sum rule and Lattice QCD approaches. However, the form factor related uncertainties mostly cancel in the ratios ${\cal B}(B \to \rho \gamma)/{\cal B}(B \to K^* \gamma)$ and $\Delta = (\Delta^{+0}+ \Delta^{-0})/2$, where $\Delta^{\pm 0} = \Gamma (B^\pm \to \rho^\pm \gamma)/ [2 \Gamma (B^0 (\bar B^0)\to \rho^0 \gamma)] - 1$, and hence their measurements will provide quantitative information on the standard model parameters, in particular the ratio of the CKM matrix elements $| V_{td}/V_{ts}|$ and the inner angle $\alpha$ of the CKM-unitarity triangle. We also calculate direct CP asymmetries for the decays $B^\pm \to \rho^\pm \gamma$ and $B^0/\bar B^0 \to \rho^0 \gamma$ and find, in conformity with the observations made in the existing literature, that the hard spectator contributions significantly reduce the asymmetries arising from the vertex corrections.Comment: 45 pages, 18 figures (requires amssymb and epsf); replaced with the revised versio