On three-body B decays to charm

I briefly describe the use of the three-body decay modes $B^0 \to D^{(*)-} D^{(*)0} K^+$ to investigate open issues in charmed meson spectroscopy, and of the time dependent $B^0 (\bar {B^0}) (t) \to D^{-} D^{+} \pi^0$ transitions for a measurement of $\cos (2 \beta)$.Comment: LaTeX, 4 pages, 4 figs. Talk at 5th International Conference on Hyperons, Charm and Beauty Hadrons (BEACH 2002), Vancouver, Canada, 25-29 Jun 200

B→Kη(′)γB\to K \eta^{(\prime)} \gamma decays in the standard model and in scenarios with universal extra dimensions

We study the radiative $B \to K \eta^{(\prime)} \gamma$ decays, which are important to investigate CP violation, and are also relevant to assess the role of the exclusive modes induced by the $b \to s \gamma$ transition to saturate the inclusive $B \to X_s \gamma$ decay rate. Moreover, these channels do not display the same hierarchy as $B \to K \eta^{(\prime)}$ modes, for which the decay into $\eta^\prime$ is enhanced with respect to one into $\eta$. The three-body radiative decays reverse the role: we find that this experimentally observed behavior (although affected by a large uncertainty in the case of the $\eta^\prime$) is reproduced in the theoretical analysis. We compute a $B^* \to K$ form factor, needed for this study, using light cone QCD sum rules, and discuss a relation expected to hold in the large energy limit for the light meson. Finally, we examine $B\to K \eta \gamma$ in two extensions of the standard model with universal extra dimensions, to investigate the sensitivity of this rare mode to such a kind of new physics effects.Comment: RevTeX, 17 pages, 7 figures. High resolution figures available upon request. Matches the published versio

Heavy-to-Light Meson Transitions in QCD

I discuss QCD sum rules determinations of the form factors governing the decay $B \to \pi (\rho) \ell \nu$. For some of these form factors the computed dependence on the momentum transferred does not agree with the expectation from the nearest pole dominance hypothesis. Relations are observed among the form factors, that seem to be compatible with equations recently derived by B.Stech. The measurement of a number of color suppressed nonleptonic B decay rates could shed light on the accuracy of the calculation of these form factors and on the factorization approximation.Comment: LaTex, 7 pages, 2 figures (files included). Talk given at the 6th International Symposium on Heavy Flavours, Pisa, 6-10 June 199

B decays to excited charm mesons

We review several aspects of the phenomenology of P-wave $\bar q Q$ mesons: mass splittings, effective strong couplings and leptonic constants. We also describe a QCD sum rule determination to order $\alpha_s$ of the form factor $\tau_{1/2}(y)$ governing the semileptonic $B$ decays to the charm doublet with $J^P=(0^+_{1/2},1^+_{1/2})$.Comment: LaTex, 3 pages, 1 figure. Talk given at 3rd International Conference on Hyperons, Charm and Beauty Hadrons, Genoa, Italy, 30 Jun - 3 Jul 199

Radiative transitions of DsJ∗(2317)D^*_{sJ}(2317) and DsJ(2460)D_{sJ}(2460)

We study radiative decays of $D^*_{sJ}(2317)$ and $D_{sJ}(2460)$ using light-cone QCD sum rules. In particular, we consider the decay modes $D^*_{sJ}(2317)\to D_s^* \gamma$ and $D_{sJ}(2460)\to D_s^{(*)} \gamma, D^*_{sJ}(2317) \gamma$ and evaluate the hadronic parameters in the transition amplitudes analyzing correlation functions of scalar, pseudoscalar, vector and axial-vector quark currents. In the case of $D^*_{sJ}(2317)\to D_s^* \gamma$ we also consider determinations based on two different correlation functions in HQET. The decay widths turn out to be different than previous estimates obtained by other methods; the results favour the interpretation of $D^*_{sJ}(2317)$ and $D_{sJ}(2460)$ as ordinary $\bar c s$ mesons.Comment: RevTex, 23 pages, 9 eps figure

Configurational Entropy can disentangle conventional hadrons from exotica

We evaluate the Configurational Entropy (CE) for scalar mesons and for $J^P=\frac{1}{2}^+$ baryons in a holographic approach, varying the dimension of boundary theory operators and using the soft-wall dual model of QCD. We find that hybrid and multiquark mesons are characterized by an increasingly large CE. A similar behavior is observed for $J^P=\frac{1}{2}^+$ baryons, where the CE of pentaquarks is larger than for three-quark baryons, for same radial number. Configurational Entropy seems relevant in disentangling conventional hadrons from exotica.Comment: 13 pages, 4 figure

Identifying DsJ(2700)D_{sJ}(2700) through its decay modes

We study how to assign the recently observed $D_{sJ}(2700)$ meson to an appropriate level of the $c \bar s$ spectrum by the analysis of its decay modes in final states comprising a light pseudoscalar meson. We use an effective lagrangian approach with heavy quark and chiral symmetries, obtaining that the measurement of the $D^* K$ decay width would allow to distinguish between two possible assignments.Comment: RevTex, 6 pages - references adde

QCD Interactions of Heavy Mesons with Pions by Light-Cone Sum Rules

Light-cone QCD sum rules are employed to compute the strong coupling constants: g_{B^* B^* pi}, g_{B_1 B_0 pi} and g_{B_1 B^* pi}, where (B,B^*) and (B_0,B_1) are negative and positive parity (0^-,1^-) and (0^+,1^+) \bar qQ doublets. The couplings are calculated both for finite values of the heavy quark mass and in the infinite heavy quark mass limit, deriving sum rules for m_Q \to \infty.Comment: Latex, 23 pages, 6 figures. Revised version to appear in Z. Phys.