We investigate the leading-twist light-cone distribution amplitudes for the pion and kaon, based on the nonlocal chiral quark model from the instanton vacuum. Effects of explicit flavor SU(3)-symmetry breaking are taken into account. The Gegenbauer moments are computed, analyzed and compared with those of other models. The one-loop QCD evolution of the moments is briefly discussed. The transverse momentum distributions are also discussed for the pion and kaon light-cone wave functions.

We assume that all quark and lepton $3\times 3$ mass matrices which appear in the standard model Lagrangian (after spontaneous symmetry breaking) with neutrinos being treated as Dirac particles have the triangular form. Such matrices have not only less nonzero elements (three of them are equal to zero) but also lead to very asymmetrical decomposition into one diagonal and two unitary matrices for quarks and leptons. We also assume that unitary matrices which transform flavor into definite mass states for right-handed components (weakly noninteracting) in the same weak isospin doublet are equal. Using all available experimental data on quark and lepton masses and mixing angles, treating in the universal way quarks and leptons, we determine the triangular mass matrices for up and down-type quarks, neutrinos and charged leptons and as a consequence mixing matrices for left-handed and right-handed components. As the result of the fit we get predictions for the neutrino masses including smallest neutrino mass. The calculations without $CP$ violation and with inclusion of this effect in quark sector are also presented.

We calculate the fraction of ${}^8\mathrm{B}$ solar neutrinos that arrive at the Earth as a ${\nu }_2$ mass eigenstate as a function of the neutrino energy. Weighting this fraction with the ${}^8\mathrm{B}$ neutrino energy spectrum and the energy dependence of the cross section for the charged current interaction on deuteron with a threshold on the kinetic energy of the recoil electrons of 5.5 MeV, we find the integrated weighted fraction of ${\nu }_2$’s to be $(91\pm 2)\%$ at the 95% CL. This energy weighting procedure corresponds to the charged current response of the Sudbury Neutrino Observatory (SNO). We have used SNO’s current best fit values for the solar mass squared difference and the mixing angle, obtained by combining the data from all solar neutrino experiments and the reactor data from KamLAND. The uncertainty on the ${\nu }_2$ fraction comes primarily from the uncertainty on the solar $\delta m^2$ rather than from the uncertainty on the solar mixing angle or the standard solar model. Similar results for the Super-Kamiokande experiment are also given. We extend this analysis to three neutrinos and discuss how to extract the modulus of the Maki-Nakagawa-Sakata mixing matrix element ${\mathrm{U}}_{e2}$ as well as place a lower bound on the electron number density in the production region for ${}^8\mathrm{B}$ solar neutrinos.

Using the current world’s largest data sample of $\psi (3770)$ decays, we present results of a search for the non-$D\overline{D}$ decay $\psi (3770)\to K_S^0{K}_L^0$. We find no signal, and obtain an upper limit of $\sigma (e^{+}{e}^{-}\to \psi (3770)\to K_S^0{K}_L^0)<0.07\mathrm{pb}$ at 90% confidence level (CL). Our result tests a theoretical prediction for the upper bound on $\mathcal{B}(\psi (3770)\to K_S^0{K}_L^0)$ based on a charmonia-mixing model.

We compare constraints on the gluon polarization in the nucleon obtained in next-to-leading order global QCD fits to polarized deep inelastic scattering data with those coming from observables more directly linked to the gluon polarization, such as the double spin asymmetry measured by PHENIX at RHIC, and high-$p_T$ hadron production studied by COMPASS at CERN.

We confront the predictions of S. Hod [Phys. Rev. D 60, 104053 (1999)] for the late-time decay rate of black hole perturbations with numerical data. Specifically, we ask two questions: First, are corrections to the Price tail dominated by logarithmic terms, as predicted by Hod? Second, if there were logarithmic correction terms, do they take the specific form predicted in Hod’s paper? The answer to both questions is “no.”

New charged solutions describing black holes with squashed horizons in 5D dilaton gravity are presented. The black hole spacetimes are asymptotically locally flat and have a spacial infinity $R\times S^1\hookrightarrow S^2$. The solutions are analyzed and their thermodynamics is discussed by using the counterterm method.

In standard general-relativistic cosmology, for fluids with a linear equation of state (EoS) $P=w\rho$ or scalar fields, the high isotropy of the universe requires special initial conditions: singularities are velocity dominated and anisotropic in general. In brane world effective 4-dimensional cosmological models an effective term, quadratic in the energy density, appears in the evolution equations, which has been shown to be responsible for the suppression of anisotropy and inhomogeneities at the singularity under reasonable assumptions. Thus in the brane world isotropy is generically built in, and singularities are matter dominated. There is no reason why the effective EoS of matter should be linear at the highest energies, and an effective nonlinear EoS may describe dark energy or unified dark matter (Paper I [K. Ananda and M. Bruni, preceding article, Phys. Rev. D 74, 023523 (2006).]). In view of this, here we investigate the effects of a quadratic EoS in homogenous and inhomogeneous anisotropic cosmological models in general relativity, in order to understand if in this standard context the quadratic EoS can isotropize the universe at early times. With respect to Paper I [K. Ananda and M. Bruni, preceding article, Phys. Rev. D 74, 023523 (2006).], here we use the simplified EoS $P=\alpha \rho +{\rho }^2/{\rho }_c$, which still allows for an effective cosmological constant and phantom behavior, and is general enough to analyze the dynamics at high energies. We first study homogenous and anisotropic Bianchi I and V models, focusing on singularities. Using dynamical systems methods, we find the fixed points of the system and study their stability. We find that models with standard nonphantom behavior are in general asymptotic in the past to an isotropic fixed point IS, i.e. in these models even an arbitrarily large anisotropy is suppressed in the past: the singularity is matter dominated. Using covariant and gauge-invariant variables, we then study linear anisotropic and inhomogeneous perturbations about the homogenous and isotropic spatially flat models with a quadratic EoS. We find that, in the large-scale limit, all perturbations decay asymptotically in the past, indicating that the isotropic fixed point IS is the general asymptotic past attractor for nonphantom inhomogeneous models with a quadratic EoS.

We investigate the general relativistic dynamics of Robertson-Walker models with a nonlinear equation of state (EoS), focusing on the quadratic case $P=P_o+\alpha \rho +\beta {\rho }^2$. This may be taken to represent theTaylor expansion of any arbitrary barotropic EoS, $P(\rho )$. With the right combination of $P_o$, $\alpha$ and $\beta$, it serves as a simple phenomenological model for dark energy, or even unified dark matter. Indeed we show that this simple model for the EoS can produce a large variety of qualitatively different dynamical behaviors that we classify using dynamical systems theory. An almost universal feature is that accelerated expansion phases are mostly natural for these nonlinear EoS’s. These are often asymptotically de Sitter thanks to the appearance of an effective cosmological constant. Other interesting possibilities that arise from the quadratic EoS are closed models that can oscillate with no singularity, models that bounce between infinite contraction/expansion and models which evolve from a phantom phase, asymptotically approaching a de Sitter phase instead of evolving to a “big rip”. In a second paper we investigate the effects of the quadratic EoS in inhomogeneous and anisotropic models, focusing, in particular, on singularities.

We have measured the mechanical loss of a dielectric multilayer reflective coating (ion-beam sputtered ${\mathrm{SiO}}_2$ and ${\mathrm{Ta}}_2{\mathrm{O}}_5$) in cooled mirrors. The loss was nearly independent of the temperature ($4\mathrm{K}\sim 300\mathrm{K}$), frequency, optical loss, and stress caused by the coating, and the details of the manufacturing processes. The loss angle was $(4\sim 6)\times {10}^{-4}$. The temperature independence of this loss implies that the amplitude of the coating thermal noise, which is a severe limit in any precise measurement, is proportional to the square root of the temperature. Sapphire mirrors at 20 K satisfy the requirement concerning the thermal noise of even future interferometric gravitational wave detector projects on the ground, for example, LCGT.

We extend the parameter space of minimal supergravity to negative values of $m_0^2$, the universal scalar mass parameter defined at the grand unified scale. After evolving to the weak scale, all scalars can be nontachyonic with masses consistent with collider constraints. This region of parameter space is typically considered excluded by searches for charged dark matter, since the lightest standard model superpartner is a charged slepton. However, if the gravitino is the lightest supersymmetric particle, the charged slepton decays, and this region is allowed. This region provides qualitatively new possibilities for minimal supergravity, including spectra with light sleptons and very heavy squarks, and models in which the lightest slepton is the selectron. We show that the $m_0^2<0$ region is consistent with low-energy precision data and discuss its implications for particle colliders. These models may provide signals of supersymmetry in even the first year of operation at the Large Hadron Collider.

We consider multiple ${\mathrm{TeV}}^{-1}$-size extra compact dimensions in an asymmetric string compactification scenario in which the standard model (SM) gauge bosons can propagate into the ${\mathrm{TeV}}^{-1}$-size extra dimensions while the SM fermions are confined to the usual SM ${\mathrm{D}}_3$-brane. We calculate the contributions that the Kaluza-Klein (KK) excitations of the gluons, $g^{*}$’s, make to the multijet cross sections in proton-proton collisions at the LHC energy. At very high $p_T$, the dijet signal will either be enhanced significantly due to virtual $g^{*}$ exchanges or place a lower bound on the compactification scale of about 8 TeV. We find that the dijet signal is very sensitive to three parameters—the compactification scale, the string scale, and the number of extra dimensions. Thus, although the dijet signal is much more sensitive to KK effects, the dijet signal alone does not provide sufficient information to deduce the number of extra dimensions nor the compactification scale. However, the three-jet signal, which is not sensitive to the string scale, can be analyzed in conjunction with the dijet signal to extract all three parameters. For proton-proton collisions at the LHC energy, the three-jet signal can be significantly enhanced by KK contributions for a compactification scale of about 4–5 TeV.

We present a complete calculation of the SU(3)-breaking corrections to the hyperon vector form factors up to $\mathcal{O}(p^4)$ in heavy baryon chiral perturbation theory. Because of the Ademollo-Gatto theorem, at this order the results do not depend on unknown low energy constants and allow to test the convergence of the chiral expansion. We complete and correct previous calculations and find that $\mathcal{O}(p^3)$ and $\mathcal{O}(1/M_0)$ corrections are important. We also study the inclusion of the decuplet degrees of freedom, showing that in this case the perturbative expansion is jeopardized. These results raise doubts on the reliability of the chiral expansion for hyperons.

In this article, we analyze the vertices $D^{*}{D}_{s}K$, $D_s^{*}DK$, $D_0{D}_{s}K$, and $D_{s0}DK$ within the framework of the light-cone QCD sum rules approach in an unified way. The strong coupling constants $G_{D^{*}{D}_{s}K}$ and $G_{D_s^{*}DK}$ are important parameters in evaluating the charmonium absorption cross sections in searching for the quark-gluon plasmas. Our numerical values of the $G_{D^{*}{D}_{s}K}$ and $G_{D_s^{*}DK}$ are compatible with the existing estimations although somewhat smaller; the $SU(4)$ symmetry breaking effects are very large, about 60%. For the charmed scalar mesons $D_0$ and $D_{s0}$, we take the point of view that they are the conventional $c\overline{u}$ and $c\overline{s}$ mesons, respectively, and calculate the strong coupling constants $G_{D_0{D}_{s}K}$ and $G_{D_{s0}DK}$ with the vector interpolating currents. The numerical values of the scalar-$D_{s}K$ and scalar-$DK$ coupling constants $G_{D_0{D}_{s}K}$ and $G_{D_{s0}DK}$ are compatible with the existing estimations—the large values support the hadronic dressing mechanism. Furthermore, we study the dependence of the four strong coupling constants $G_{D^{*}{D}_{s}K}$, $G_{D_s^{*}DK}$, $G_{D_0{D}_{s}K}$, and $G_{D_{s0}DK}$ on the nonperturbative parameter $a_4$ of the twist-2 $K$ meson light-cone distribution amplitude.

In experiment with the SND detector at the VEPP-2M $e^{+}{e}^{-}$ collider the $e^{+}{e}^{-}\to \eta \gamma$ cross section was measured in the center-of-mass energy range $E=0.60–1.38\mathrm{GeV}$ with the integrated luminosity of $27.8{\mathrm{pb}}^{-1}$. The measured cross section is well described by the vector meson dominance model with contributions from the $\rho (770)$, $\omega (783)$, $\varphi (1020)$, ${\rho }^{\prime }(1465)$ resonances and agrees with results of previous measurements. The decay probabilities $\mathcal{B}(\varphi \to \eta \gamma )$, $\mathcal{B}(\omega \to \eta \gamma )$ and $\mathcal{B}(\rho \to \eta \gamma )$ were measured with the accuracies better than or comparable to the world averages.

We present measurements of the branching fractions for the Cabbibo suppressed decays $D^{+}\to {\pi }^{+}{\pi }^0$ and $D^{+}\to K^{+}{\pi }^0$ based on a data sample corresponding to an integrated luminosity of $124.3{\mathrm{fb}}^{-1}$. The data were taken with the BABAR detector at the PEP-II $B$ Factory operating on and near the $\mathit{{\rm Y}}(4S)$ resonance. We find $\mathcal{B}(D^{+}\to {\pi }^{+}{\pi }^0)=(1.25\pm 0.10\pm 0.09\pm 0.04)\times {10}^{-3}$ and $\mathcal{B}(D^{+}\to K^{+}{\pi }^0)=(2.52\pm 0.47\pm 0.25\pm 0.08)\times {10}^{-4}$, where the first uncertainty is statistical, the second systematic and the last error is due to the uncertainties in the absolute branching fraction scale for $D^{+}$ mesons. This represents the first observation of the doubly Cabibbo-suppressed $D^{+}\to K^{+}{\pi }^0$ decay mode and a new measurement of the $D^{+}\to {\pi }^{+}{\pi }^0$ branching fraction.

We present measurements of $CP$-violating asymmetries and branching fractions for the decays $B^{+}\to \omega {\pi }^{+}$, $B^{+}\to \omega K^{+}$, and $B^0\to \omega K^0$. The data sample corresponds to $232\times {10}^6$ $B\overline{B}$ pairs produced by $e^{+}{e}^{-}$ annihilation at the ${\rm Y}(4S)$ resonance. For the decay $B^0\to \omega K_S^0$, we measure the time-dependent $CP$-violation parameters $\mathrm{S}={0.51}_{-0.39}^{+0.35}\pm 0.02$, and $\mathrm{C}=-{0.55}_{-0.26}^{+0.28}\pm 0.03$. We also measure the branching fractions, in units of ${10}^{-6}$, $\mathcal{B}(B^{+}\to \omega {\pi }^{+})=6.1\pm 0.7\pm 0.4$, $\mathcal{B}(B^{+}\to \omega K^{+})=6.1\pm 0.6\pm 0.4$, and $\mathcal{B}(B^0\to \omega K^0)=6.2\pm 1.0\pm 0.4$, and charge asymmetries ${\mathcal{A}}_{\mathrm{ch}}(B^{+}\to \omega {\pi }^{+})=-0.01\pm 0.10\pm 0.01$ and ${\mathcal{A}}_{\mathrm{ch}}(B^{+}\to \omega K^{+})=0.05\pm 0.09\pm 0.01$.

We solve the effective Dirac equation for massless fermions during inflation in the simplest gauge, including all one loop corrections from quantum gravity. At late times the result for a spatial plane wave behaves as if the classical solution were subjected to a time-dependent field strength renormalization of $Z_2(t)=1-\frac{17}{4\pi }G{H}^2\ln (a)+O(G^2)$. We show that this also follows from making the Hartree approximation, although the numerical coefficients differ.

Gravitational lensing by traversable Lorentzian wormholes is a new possibility which is analyzed here in the strong field limit. Wormhole solutions are considered in the Einstein minimally coupled theory and in the brane world model. The observables in both the theories show significant differences from those arising in the Schwarzschild black hole lensing. As a corollary, it follows that wormholes with zero Keplerian mass exhibit lensing properties which are qualitatively (though not quantitatively) the same as those of a Schwarzschild black hole. Some special features of the considered solutions are pointed out.

The present spatial distribution of galaxies in the Universe is non-Gaussian, with 40% skewness in $50h^{-1}\mathrm{Mpc}$ spheres, and remarkably little is known about the information encoded in it about cosmological parameters beyond the power spectrum. In this work we present an attempt to bridge this gap by studying the bispectrum, paying particular attention to a joint analysis with the power spectrum and their combination with CMB data. We address the covariance properties of the power spectrum and bispectrum including the effects of beat coupling that lead to interesting cross-correlations, and discuss how baryon acoustic oscillations break degeneracies. We show that the bispectrum has significant information on cosmological parameters well beyond its power in constraining galaxy bias, and when combined with the power spectrum is more complementary than combining power spectra of different samples of galaxies, since non-Gaussianity provides a somewhat different direction in parameter space. In the framework of flat cosmological models we show that most of the improvement of adding bispectrum information corresponds to parameters related to the amplitude and effective spectral index of perturbations, which can be improved by almost a factor of 2. Moreover, we demonstrate that the expected statistical uncertainties in ${\sigma }_8$ of a few percent are robust to relaxing the dark energy beyond a cosmological constant.