121330294
Global analysis of D→ PV decays and SU(3) flavor symmetry breaking effects
We investigate in detail both the Cabibbo-allowed and singly Cabibbo-suppressed D→ PV decays based on the diagrammatic decomposition in the factorization formalism. Two sets of solutions discarded in the literature are picked up and discussed carefully. It is found that one of these solutions can provide satisfactory explanation in a natural manner on the process $D^+\to \overline {K}^0K^{*+}$ which is thought to be a puzzle. The relations EV+EP=0 and AV+AP=0 are badly broken, which indicates that the exchange and annihilation diagrams may receive contributions from more sources other than the $q\overline{q}$ intermediate state interactions. It is shown that, to have a consistent explanation to the experimental data with reasonable values for the parameters a1 and a2, the SU(3) symmetry breaking effects have to be considered. The SU(3) flavor symmetry breaking effects due to mass factors and due to formfactors and decay constants are analyzed in detail.
118041104
Correction to the Running of Gauge Couplings out of Extra Dimensional Gravity
We study the gravitational correction to the gauge couplings in the extra dimension model where the gravity propagates in the (4+n)-dimensional bulk. We show by explicit calculation in the background field method that the one-loop correction coming from graviton Kaluza-Klein states is nontrivial and tends to make the theory anti-asymptotically free. For the theory characterized with asymptotic freedom, the correction will induce a nontrivial UV-stable fixed point. This may lead to an interesting possibility that the non-abelian gauge coupling constants $g_2$ and $g_3$ in the SM and that of the gravity $g_{\kappa}$ unify at the fixed point in the limit of high energy scale.
117848077
Could $Z_{b}(10610)$ be a $B^{*}\bar{B}$ molecular state?
Assuming the newly observed structure $Z_{b}(10610)$ as a bottomonium-like molecular state $B^{*}\bar{B}$, we calculate its mass in the framework of QCD sum rules. The numerical result is $10.54\pm0.22 GeV$ for $B^{*}\bar{B}$, which coincide with the mass of $Z_{b}(10610)$. This consolidates the statement made by Belle Collaboration that the $Z_{b}(10610)$ resonance could be a $B^{*}\bar{B}$ molecular state.
9148058
Challenge to the a theorem in six dimensions.
The possibility of a strong a theorem in six dimensions is examined in multiflavor ϕ^{3} theory. Contrary to the case in two and four dimensions, we find that, in perturbation theory, the relevant quantity a[over ˜] increases monotonically along flows away from the trivial fixed point. a[over ˜] is a natural extension of the coefficient a of the Euler term in the trace anomaly, and it arises in any even spacetime dimension from an analysis based on Weyl consistency conditions. We also obtain the anomalous dimensions and beta functions of multiflavor ϕ^{3} theory to two loops. Our results suggest that some new intuition about the a theorem is in order.
11989158
Heavy to light meson exclusive semileptonic decays in effective field theory of heavy quarks
We present a general study of exclusive semileptonic decays of heavy (B,D,B-s) to light (pi,rho,K,K-*) mesons in the framework of the effective field theory of heavy quarks. The transition matrix elements of these decays can be systematically characterized by a set of wave functions which are independent of the heavy quark mass except for the implicit scale dependence. Form factors for all these decays are calculated consistently within the effective theory framework using the light cone sum rule method at the leading order of the 1/m(Q) expansion. The branching ratios of these decays are evaluated, and the heavy and light flavor symmetry breaking effects are investigated. We also give a comparison of our results and the predictions from other approaches, among which are the relations proposed recently in the framework of large energy effective theory.
36756339
A MORE PRECISE EXTRACTION OF |Vcb| IN HQEFT OF QCD
The more precise extraction for the CKM matrix element |Vcb| in the heavy quark effective field theory (HQEFT) of QCD is studied from both exclusive and inclusive semileptonic B decays. The values of relevant nonperturbative parameters up to order $1/m^2_Q$ are estimated consistently in HQEFT of QCD. Using the most recent experimental data for B decay rates, |Vcb| is updated to be |Vcb|=0.0395±0.0011expt±0.0019theor from B→D*lν decay and |Vcb|=0.0434±0.0041expt±0.0020theor from B→Dlν decay as well as |Vcb|=0.0394±0.0010expt±0.0014theor from inclusive B→Xclν decay.
117276480
The Sun's Origin, Composition and Source of Energy
Composition: Diffusion enriches lighter elements and the lighter isotopes of each element at the solar surface. When corrected for mass fractionation, the most abundant nuclide that accreted on the Sun was shown to be Fe, the decay product of doubly-magic Ni; the next most abundant nuclide is the doublymagic O. These nuclides were recently observed in the ash of SN 1987A. The most abundant elements Fe, Ni, O, Si, S, Mg, and Ca are the seven, even-Z elements that Harkins found to comprise 99% of ordinary meteorites. The least abundant elements Li, Be and B have loosely bound nucleons, confirming a link between abundance and nuclear structure hidden beneath the Sun’s H-rich surface, with one conspicuous and important exception an excess of protons.