We determine the complete set of axial and vector form factors for the $D_s\to \varphi \ell \nu$ decay from full lattice QCD for the first time. The valence quarks are implemented using the highly improved staggered quark action and we normalize the appropriate axial and vector currents fully nonperturbatively. The $q^2$ and angular distributions we obtain for the differential rate agree well with those from the BABAR experiment and, from the total branching fraction, we obtain $V_{cs}=1.017(63)$, in good agreement with that from $D\to K\ell \nu$ semileptonic decay. We also find the mass and decay constant of the $\varphi$ meson in good agreement with experiment, showing that its decay to $K\overline{K}$ (which we do not include here) has at most a small effect. We include an Appendix on nonperturbative renormalization of the complete set of staggered vector and axial vector bilinears needed for this calculation.

We study ground and radial excitations of flavor singlet and flavored pseudoscalar mesons within the framework of the rainbow-ladder truncation using an infrared massive and finite interaction in agreement with recent results for the gluon-dressing function from lattice QCD and Dyson-Schwinger equations. Whereas the ground-state masses and decay constants of the light mesons as well as charmonia are well described, we confirm previous observations that this truncation is inadequate to provide realistic predictions for the spectrum of excited and exotic states. Moreover, we find a complex conjugate pair of eigenvalues for the excited $D_{(s)}$ mesons, which indicates a non-Hermiticity of the interaction kernel in the case of heavy-light systems and the present truncation. Nevertheless, limiting ourselves to the leading contributions of the Bethe-Salpeter amplitudes, we find a reasonable description of the charmed ground states and their respective decay constants.

We solve the hyper-radial Schrödinger equation with Cornell interaction to find the baryonic wave function. Thereby, we investigate the baryonic Isgur–Wise function in hyperspherical coordinates. Using the obtained Isgur–Wise function, we find the decay width of heavy-baryon transitions. An analysis of masses of baryons and the differential decay width for some heavy baryons is also presented. Comparison with other model calculations is motivating.

Within the framework of the perturbative QCD approach, we study the two-body charmless decays $B\to K_1(1270)(K_1(1400))\pi (K)$. We find the following results: (i) The decays ${\overline{B}}^0\to K_1(1270{)}^{+}{\pi }^{-}$, $K_1(1400{)}^{+}{\pi }^{-}$ are incompatible with the present experimental data. There exists a similar situation for the decays ${\overline{B}}^0\to a_1(1260{)}^{+}{K}^{-}$, $b_1(1235{)}^{+}{K}^{-}$, which are usually considered that the nonperturbative contributions are needed to explain the data. But the difference is that the nonperturbative contributions seem to play opposite roles in these two groups of decays. (ii) The pure annihilation type decays ${\overline{B}}^0\to K_1^{\pm }(1270)K^{\mp }$, $K_1^{\pm }(1400)K^{\mp }$ are good channels to test whether an approach can be used to calculate correctly the strength of the penguin-annihilation amplitudes. Their branching ratios are predicted at $10^{-7}$ order, which are larger than the QCDF results. (iii) The dependence of the direct $CP$-violating asymmetries of these decays on the mixing angle ${\theta }_{K_1}$ are also considered.

The transverse polarization of $\mathrm{\Lambda }$ hyperons was measured in inclusive quasireal photoproduction for various target nuclei ranging from hydrogen to xenon. The data were obtained by the HERMES experiment at HERA using the 27.6 GeV lepton beam and nuclear gas targets internal to the lepton storage ring. The polarization observed is positive for light target nuclei and is compatible with zero for krypton and xenon.

We provide an update of the global fits of the couplings of the 125.5 GeV Higgs boson using all publicly available experimental results from run 1 of the LHC as per summer 2014. The fits are done by means of the new public code Lilith 1.0. We present a selection of results given in terms of signal strengths, reduced couplings, and for the two-Higgs-doublet models of type I and II.

We searched for the emission of microwave radiation in the Ku band generated by a 95 keV electron beam in air. We unequivocally detected the radiation, and measured its yield and angular dependence. Both the emitted power and its angular pattern are well described by a model, where microwave photons are generated via bremsstrahlung in the free-electron atomic-nucleus collisions, during the slowdown of the electrons. As a consequence, the radiation is not isotropic but peaked in the forward direction. The emission yield scales proportionally with the number of electrons. This contrasts a previous claim that the yield scales with the number squared, due to coherence. With a Monte Carlo simulation we extrapolate our results to the ultra high energy cosmic ray energy range.

Recently Schwarz put forward a conjecture that the world-volume action of a probe D3-brane in an ${\mathrm{AdS}}_5\times {\mathbb{S}}^5$ background of type IIB superstring theory can be reinterpreted as the highly effective action (HEA) of four-dimensional $\mathcal{N}=4$ superconformal field theory on the Coulomb branch. We argue that the HEA can be derived from the noncommutative (NC) field theory representation of the AdS/CFT correspondence and the Seiberg-Witten (SW) map defining a spacetime field redefinition between ordinary and NC gauge fields. It is based only on the well-known facts that the master fields of large $N$ matrices are higher-dimensional NC $U(1)$ gauge fields and the SW map is a local coordinate transformation eliminating $U(1)$ gauge fields known as the Darboux theorem in symplectic geometry.

First, we develop the counting rule for Nambu-Goldstone bosons to the system including two-time derivative terms. In this case, the type-II Nambu-Goldstone bosons may appear along with the massive Nambu-Goldstone ones. The number of the bosons is not reduced in contrast to the system without two-time derivative terms. We also investigate the reduction of the degrees of freedom from the perspective of the Dirac-Bergmann theory of constraints and reproduce the counting rule for Nambu-Goldstone bosons without Lorentz invariance. Then, we construct the generic Higgs model and study a Higgs phenomenon with these Nambu-Goldstone bosons on the basis of the Dirac-Bergmann theory. We show that the gauge fields in this system absorb all of the Nambu-Goldstone bosons such as the type-I, type-II, and massive ones.

We describe new methods for denoising and detection of gravitational waves embedded in additive Gaussian noise. The methods are based on total variation denoising algorithms. These algorithms, which do not need any a priori information about the signals, have been originally developed and fully tested in the context of image processing. To illustrate the capabilities of our methods we apply them to two different types of numerically-simulated gravitational wave signals, namely bursts produced from the core collapse of rotating stars and waveforms from binary black hole mergers. We explore the parameter space of the methods to find the set of values best suited for denoising gravitational wave signals under different conditions such as waveform type and signal-to-noise ratio. Our results show that noise from gravitational wave signals can be successfully removed with our techniques, irrespective of the signal morphology or astrophysical origin. We also combine our methods with spectrograms and show how those can be used simultaneously with other common techniques in gravitational wave data analysis to improve the chances of detection.

Tachyon inflation is reconsidered by using the recent observational data obtained from Planck-2013 and BICEP2. The Hamilton-Jacobi formalism is picked out as a desirable approach in this work, which allows one to easily obtain the main parameters of the model. The Hubble parameter is supposed as a power-law and exponential function of the scalar field, and each case is considered separately. The constraints on the model, which come from observational data, are explained during the work. The results show a suitable value for the tensor spectral index and an appropriate form of the potential.

We consider two toy models of open inflation and investigate their ability to give a suppression of scalar power on large scales while also satisfying observational constraints on the spatial curvature of the Universe. Qualitatively we find that both models are indeed capable of fulfilling these two requirements, but we also see that effects of the quantum tunneling must be carefully taken into account if we wish to make quantitative predictions.

In this work the bumblebee model for spontaneous Lorentz symmetry breaking is considered in the context of spherically symmetric astrophysical bodies. A discussion of the modified equations of motion is presented and constraints on the parameters of the model are perturbatively obtained.

We make a phenomenological study of a model with two inert doublets plus one Higgs doublet [$\mathrm{I}(2+1)\mathrm{HDM}$] which is symmetric under a $Z_2$ group, preserved after electroweak symmetry breaking by the vacuum alignment $(0,0,v)$. This model may be regarded as an extension to the model with one inert doublet plus one Higgs doublet [$\mathrm{I}(1+1)\mathrm{HDM}$], by the addition of an extra inert scalar doublet. The neutral fields from the two inert doublets provide a viable dark matter (DM) candidate which is stabilized by the conserved $Z_2$ symmetry. We study the new Higgs decay channels offered by the scalar fields from the extra doublets and their effect on the standard model Higgs couplings, including a new decay channel into (off-shell) photon(s) plus missing energy, which distinguishes the $\mathrm{I}(2+1)\mathrm{HDM}$ from the $\mathrm{I}(1+1)\mathrm{HDM}$. Motivated by supersymmetry, which requires an even number of doublets, we then extend this model into a model with four inert doublets plus two Higgs doublets [$\mathrm{I}(4+2)\mathrm{HDM}$] and study the phenomenology of the model with the vacuum alignment $(0,0,0,0,v,v)$. This scenario offers a wealth of Higgs signals, the most distinctive ones being cascade decays of heavy Higgs states into inert ones. Finally, we also remark that the smoking-gun signature of all the considered models is represented by invisible Higgs decays into the lightest inert Higgs bosons responsible for DM.

Recently, Weinberg proposed a scenario where Goldstone bosons may be masquerading as fractional cosmic neutrinos. We calculate the energy loss rates through the emission of these Goldstone bosons in a postcollapse supernova core. Invoking the well-established emissivity bound from the Supernova 1987A observations and simulations, we find that nuclear bremsstrahlung processes can notably impose a bound on the Goldstone boson coupling to the Standard Model Higgs, $g$, dependent on the mass of the associated radial field, $m_r$. We apply the supernova emissivity bound at typical core conditions: a density of $\rho =3\times 10^{14}\mathrm{g}/{\mathrm{cm}}^3$ and a temperature $T=30\mathrm{MeV}$. Even in the conservative limit where $m_r$ is large enough compared with the Goldstone boson energies attainable at this temperature, our bound $|g|\lesssim 0.011(m_r/500\mathrm{MeV}{)}^2$ is very competitive to those derived from current and projected sensitivities of collider experiments.

We analyze the prospects for light neutralino dark matter in the minimal supersymmetric model extended by a $U(1)$ gauge group. We allow the neutralino to be an arbitrary admixture of singlet and doublet Higgsinos, as well as of the three gauginos, and we require agreement with the data from the direct and indirect dark matter detection experiments, while maintaining consistency of the model with the relic density, and with the recent Higgs data from the LHC. The constraints have implications for the structure of the lightest neutralino as a dark matter candidate, indicating that it is largely singlino, and its mass can be as light as $\sim 20\mathrm{GeV}$.

In this work, we examine the possibility of realizing a strongly first-order electroweak phase transition within the minimal classically scale-invariant extension of the standard model (SM), previously proposed and analyzed as a potential solution to the hierarchy problem. By introducing one complex gauge-singlet scalar and three (weak scale) right-handed Majorana neutrinos, the scenario was successfully rendered capable of achieving a radiative breaking of the electroweak symmetry (by means of the Coleman-Weinberg mechanism), inducing nonzero masses for the SM neutrinos (via the seesaw mechanism), presenting a pseudoscalar dark matter candidate (protected by the $CP$ symmetry of the potential), and predicting the existence of a second $CP$-even boson (with suppressed couplings to the SM content) in addition to the 125 GeV scalar. In the present treatment, we construct the full finite-temperature one-loop effective potential of the model, including the resummed thermal daisy loops, and demonstrate that finite-temperature effects induce a first-order electroweak phase transition. Requiring the thermally driven first-order phase transition to be sufficiently strong at the onset of the bubble nucleation (corresponding to nucleation temperatures $T_N\sim 100–200\mathrm{GeV}$) further constrains the model’s parameter space; in particular, an $\mathcal{O}(0.01)$ fraction of the dark matter in the Universe may be simultaneously accommodated with a strongly first-order electroweak phase transition. Moreover, such a phase transition disfavors right-handed Majorana neutrino masses above several hundreds of GeV, confines the pseudoscalar dark matter masses to $\sim 1–2\mathrm{TeV}$, predicts the mass of the second $CP$-even scalar to be $\sim 100–300\mathrm{GeV}$, and requires the mixing angle between the $CP$-even components of the SM doublet and the complex singlet to lie within the range $0.2\lesssim \sin \omega \lesssim 0.4$. The obtained results are displayed in comprehensive exclusion plots, identifying the viable regions of the parameter space. Many of these predictions lie within the reach of the next LHC run.

In an effective theory approach, the full minimal set of leading contributions to anomalous charged-current top couplings comprises various new trilinear $tbW$ as well as quartic $tbf{f}^{\prime }$ interaction vertices, some of which are related to one another by equations of motion. While much effort in earlier work has gone into the extraction of the trilinear couplings from single top measurements, we argue in this article that these structures can be assessed independently by other observables, while single top production forms a unique window to the four-fermion sector. An effective theory approach is employed to infer and classify the minimal set of such couplings from dimension six operators in the minimal flavor violation scheme. In the phenomenological analysis, we present a Monte Carlo study at detector level to quantify the expected performance of the next LHC run to bound as well as distinguish the various contact couplings. Special attention is directed toward differential final state distributions including detector effects as a means to optimize the signal sensitivity as well as the discriminative power with respect to the possible coupling structures.

This paper is devoted to a phenomenological study of ${\chi }_{c,b}$-meson production in high energy hadronic collisions in the framework of nonrelativistic QCD (NRQCD). We analyze all available experimental data on ${\chi }_c$-meson production and extract nonperturbative NRQCD matrix elements by data fitting. It is shown that measured $p_T$ spectra of ${\chi }_c$-mesons is mainly formed by color singlet components, while the $\sigma ({\chi }_{c2})/\sigma ({\chi }_{c1})$ ratio depends strongly on color octet matrix elements; this ratio becomes a highly sensitive tool to study contributions of the different NRQCD expansion terms. Predictions for ${\chi }_b$-meson production cross sections, which are obtained using NRQCD scaling rules, are also given.

Measurements of the inclusive jet cross section with the anti-$k_{\mathrm{T}}$ clustering algorithm are presented for two radius parameters, $R=0.5$ and 0.7. They are based on data from LHC proton-proton collisions at $\sqrt{s}=7\mathrm{TeV}$ corresponding to an integrated luminosity of $5.0{\mathrm{fb}}^{-1}$ collected with the CMS detector in 2011. The ratio of these two measurements is obtained as a function of the rapidity and transverse momentum of the jets. Significant discrepancies are found comparing the data to leading-order simulations and to fixed-order calculations at next-to-leading order, corrected for nonperturbative effects, whereas simulations with next-to-leading-order matrix elements matched to parton showers describe the data best.