KamLAND has measured the flux of nu;(e)'s from distant nuclear reactors. We find fewer nu;(e) events than expected from standard assumptions about nu;(e) propagation at the 99.95% C.L. In a 162 ton.yr exposure the ratio of the observed inverse beta-decay events to the expected number without nu;(e) disappearance is 0.611+/-0.085(stat)+/-0.041(syst) for nu;(e) energies >3.4 MeV. In the context of two-flavor neutrino oscillations with CPT invariance, all solutions to the solar neutrino problem except for the "large mixing angle" region are excluded.

First Results from KamLAND: Evidence for Reactor Anti-Neutrino Disappearance

This article is devoted to the perturbative renormalization of the abelian Higgs-Kibble model, within the class of renormalizable gauges which are odd under charge conjugation. The Bogoliubov Parasiuk Hepp-Zimmermann renormalization scheme is used throughout, including the renormalized action principle proved by Lowenstein and Lam. The whole study is based on the fulfillment to all orders of perturbation theory of the Slavnov identities which express the invariance of the Lagrangian under a supergauge type family of non-linear transformations involving the Faddeev-Popov ghosts. Direct combinatorial proofs are given of the gauge independence and unitarity of the physicalS operator. Their simplicity relies both on a systematic use of the Slavnov identities as well as suitable normalization conditions which allow to perform all mass renormalizations, including those pertaining to the ghosts, so that the theory can be given a setting within a fixed Fock space. Some simple gauge independent local operators are constructed.

/pdf/renormalization-of-the-abelian-higgs-kibble-model-14fr0vp7oj.pdf

Renormalization of the Abelian Higgs-Kibble Model

Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts

http://cds.cern.ch/record/495957/files/0104110.pdf

QCD Factorization in B -> pi K, pi pi decays and extraction of Wolfenstein parameters

In the heavy-quark limit, the hadronic matrix elements entering nonleptonic $B$-meson decays into two light mesons can be calculated from first principles including ``nonfactorizable'' strong-interaction corrections. The $B\to\pi K,\pi\pi$ decay amplitudes are computed including electroweak penguin contributions, SU(3) violation in the light-cone distribution amplitudes, and an estimate of power corrections from chirally-enhanced terms and annihilation graphs. The results are then used to reduce the theoretical uncertainties in determinations of the weak phases $\gamma$ and $\alpha$. In that way, new constraints in the $(\bar\rho,\bar\eta)$ plane are derived. Predictions for the $B\to\pi K, \pi\pi$ branching ratios and CP asymmetries are also presented. A good global fit to the (in part preliminary) experimental data on the branching fractions is obtained without taking recourse to phenomenological models.

QCD Factorization in B -> pi K, pi pi Decays and Extraction of Wolfenstein Parameters

We present an undated comprehensive analysis for the simplest dark matter model in which a real singlet scalar with a Z
 2 symmetry is introduced to extend the standard model. According to the observed dark matter abundance, we predict the dark matter direct and indirect detection cross sections for the whole parameter space. The Breit-Wigner resonance effect has been considered to calculate the thermally averaged annihilation cross section. It is found that three regions can be excluded by the current direct and indirect dark matter search experiments. In addition, we also discuss the implication of this model for the Higgs searches at colliders.

The real singlet scalar dark matter model

On thermal gravitational contribution to particle production and dark matter

We construct a fully back-reacted holographic dual of a four-dimensional field theory which exhibits chiral symmetry breaking. Two possible models are considered by studying the effects of a five-dimensional field, dual to the qq operator. One model has smooth geometry at all radii and the other dynamically generates a cutoff at finite radius. Both of these models satisfy Einstein's field equations. The second model has only three free parameters, as in QCD, and we show that this gives phenomenologically consistent results. We also discuss the possibility that in order to obtain linear confinement from a back-reacted model it may be necessary to consider the condensate of a dimension two operator.

AdS/QCD phenomenological models from a back-reacted geometry

Pure Gravitational Dark Matter, Its Mass and Signatures

With proper profiles of the scalar potential and the dilaton field, for the first time, the spontaneous chiral symmetry breaking in the vacuum and its restoration at finite temperature are correctly realized in the holographic QCD framework. In the chiral limit, a nonzero chiral condensate develops in the vacuum and decreases with temperature, and the phase transition is of the second order for a two-flavor case and of the first order for a three-flavor case. In the case of explicit chiral symmetry breaking, in the two-flavor case, the second-order phase transition turns into a crossover with any nonzero current quark mass, and in the three-flavor case, the first-order phase transition turns into a crossover at a finite current quark mass. The correct description of chiral symmetry breaking and restoration makes the holographic QCD models more powerful in dealing with nonperturbative QCD phenomena. This framework can be regarded as a general setup in an application of AdS/CFT to describe conventional Ginzburg-Landau-Wilson-type phase transitions, e.g. in condensed matter and cosmology systems.

Yue-Liang Wu

Papers

The real singlet scalar dark matter model

On thermal gravitational contribution to particle production and dark matter

AdS/QCD phenomenological models from a back-reacted geometry

Pure Gravitational Dark Matter, Its Mass and Signatures

Realization of chiral symmetry breaking and restoration in holographic QCD