We investigate the creation of cold dark matter (CCDM) cosmology as an alternative to explain the cosmic acceleration. Particular attention is given to the evolution of density perturbations and constraints coming from recent observations. By assuming negligible effective sound speed we compare CCDM predictions with redshift-space-distortion based $f(z){\sigma }_8(z)$ measurements. We identify a subtle issue associated with which contribution in the density contrast should be used in this test and then show that the CCDM results are the same as those obtained with $\mathrm{\Lambda }\mathrm{CDM}$. These results are then contrasted with the ones obtained at the background level. For the background tests we have used type Ia supernovae data (Union 2.1 compilation) in combination with baryonic acoustic oscillations and cosmic microwave background observations and also measurements of the Hubble parameter at different redshifts. As a consequence of the studies we have performed at both the background and perturbation levels, we explicitly show that CCDM is observationally degenerate with respect to $\mathrm{\Lambda }\mathrm{CDM}$ (dark degeneracy). The need to overcome the lack of a fundamental microscopic basis for the CCDM is the major challenge for this kind of model.

We propose a novel approach to the problem of cosmological perturbations in a braneworld model with induced gravity, which leads to a closed system of equations on the brane. We focus on a spatially closed brane that bounds the interior four-ball of the bulk space. The background cosmological evolution on the brane is now described by the normal branch, and the boundary conditions in the bulk become the regularity conditions for the metric everywhere inside the four-ball. In this approach, there is no spatial infinity or any other boundary in the bulk space since the spatial section is compact; hence, we term this setup as a no-boundary proposal. Assuming that the bulk cosmological constant is absent and employing the Mukohyama master variable, we argue that the effects of nonlocality on brane perturbations may be ignored if the brane is marginally closed. In this case, there arises a relation that closes the system of equations for perturbations on the brane. Perturbations of pressureless matter and dark radiation can now be described by a system of coupled second-order differential equations. Remarkably, this system can be exactly solved in the matter-dominated and de Sitter regimes. In this case, apart from the usual growing and decaying modes, we find two additional modes that behave monotonically on super-Hubble spatial scales and exhibit rapid oscillations with decaying amplitude on sub-Hubble spatial scales.

A wide range of models beyond the Standard Model predict charged and neutral resonances, generically called $W^{\prime }$ and $Z^{\prime }$ bosons, respectively. In this paper we study the impact of such resonances on the deep inelastic scattering of ultra-high energy neutrinos as well as on the resonant charged current ${\overline{\nu }}_e{e}^{-}$ scattering (Glashow resonance). We find that the effects of such resonances cannot be observed with the Pierre Auger Observatory or any foreseeable upgrade of it.

We review the detection of the $\mathrm{\Delta }L=2$ semileptonic meson decays of the form $M^{+}\to M^{\prime -}{\ell }^{+}{\ell }^{+}$ that we studied in a previous work, mediated by a Majorana neutrino with a mass in the range between the masses of the initial and final mesons. For such a range of masses, the Majorana neutrino will go on its mass shell, and the two charged leptons will appear at displaced vertices or, if the lifetime is long enough, most secondary vertices will fall outside the detector. We study the consequences of this effect on the experimental searches and limits that can be extracted.

We consider the scenario in which the new strong dynamics is responsible for the formation of the 125 GeV Higgs boson. The Higgs boson appears as composed of all known quarks and leptons of the Standard Model. The description of the mentioned strong dynamics is given using the $\zeta$ regularization. It allows us to construct the effective theory without ultraviolet divergences in which the $1/N_c$ expansion works naturally. It is shown that in the leading order of the $1/N_c$ expansion, the mass of the composite $h$ boson is given by $M_h=m_t/\sqrt{2}\approx 125\mathrm{GeV}$, where $m_t$ is the top-quark mass.

We generalize the Boriçi-Creutz action in such a way that the position of the second zero and the direction which breaks the hypercubic symmetry can be arbitrarily chosen, and the action has still the correct continuum limit. Minimal doubling is guaranteed if the distance between the two zeros does not become too large. Special values of this distance could turn out to be particularly convenient for efficient numerical simulations of minimally doubled fermions.

We calculate the spectrum of energy loss differences due to gluon radiation in high energy hard forward processes in proton-nucleus collisions as compared to proton-proton collisions. We find that the nuclear induced energy loss scales linearly with the beam energy. We evaluate the spectrum and “typical” energy losses in a logarithmic and large $N_c$ approximation. The energy losses found appear large enough to be phenomenologically important.

Branching fractions and $CP$-violating asymmetries of charmless ${\overline{B}}_s^0\to PPP$ decays with $P=K$, $\pi$ are studied using a simple model based on the factorization approach. The penguin-dominated modes ${\overline{B}}_s^0\to {\overline{K}}^0{K}^{+}{\pi }^{-}$ and $K^0{K}^{-}{\pi }^{+}$ have the largest rates among the three-body $B_s$ decays, and they are dominated by the $K_0^{*}(1430)$ resonances and nonresonant contributions. The branching fraction of ${\overline{B}}_s^0\to K^0{K}^{+}{K}^{-}$ is predicted to be of order $1.4\times {10}^{-6}$, which is in the middle of the measured result $(0.2–3.4)\times {10}^{-6}$ obtained by LHCb. We find sizable $CP$ violation in $K^0{\pi }^{+}{\pi }^{-}$, $K^0{\pi }^0{\pi }^0$, $K^0{K}^{+}{K}^{-}$, and $K_S{K}_S{K}_S$ channels. Just as the $B_u$ sector, the $CP$ asymmetries of ${\overline{B}}_s^0\to K^0{\pi }^{+}{\pi }^{-}$ and ${\overline{B}}_s^0\to K^0{K}^{+}{K}^{-}$ have similar magnitudes but are opposite in sign. Several model-independent relations based on $U$-spin symmetry for $CP$ asymmetries are derived. Although they cannot be tested by the present available data, they can be checked by the dynamical calculations. Since the $U$-spin symmetry that relates various matrix elements of scalar densities, for example, $⟨K^{0}K|\overline{d}q|0⟩$ and $⟨{\overline{K}}^0\pi |\overline{s}q|0⟩$, is badly broken, the derived $U$-spin relations are generally not well respected.

The study of regional $CP$ asymmetry in Dalitz plots of charm (& beauty) decays gives us more information about the underlying dynamics than the ratio between total rates. In this paper we explore the consequences of the constraint from $CPT$ symmetry with emphasis on three-body $D$ decays. We show simulations of $D^{\pm }\to {\pi }^{\pm }{K}^{+}{K}^{-}$ and discuss correlations with measured $D^{\pm }\to {\pi }^{\pm }{\pi }^{+}{\pi }^{-}$. There are important comments about analysis of recent LHCb data in $CP$ asymmetries for $B^{\pm }$ decays to three-body final states.

Two charm-strange mesons, the $D_{s1}^{*}(2710)$ and the $D_{sJ}^{*}(2860)$, have recently been observed by several experiments. There has been speculation in the literature that the $D_{s1}^{*}(2710)$ is the $2{}^3{S}_1(c\overline{s})$ state and the $D_{sJ}^{*}(2860)$ is the $1{}^3{D}_1(c\overline{s})$ state. In this paper we explore this and other explanations in the context of the relativized quark model and the pseudoscalar emission decay model. We conclude that the $D_{s1}^{*}(2710)$ is most likely the $1{}^3{D}_1(c\overline{s})$ state and the $D_{sJ}^{*}(2860)$ is most likely the $1{}^3{D}_3(c\overline{s})$ state with the $1D_2$ resonances also contributing to the observed signals and explaining the observed ratios of branching ratios to $D^{*}K$ and $DK$ final states. We point out that measuring the $D_{sJ}^{*}(2860)$ spin can support or eliminate this explanation and that there are six excited $D_s$ states in this mass region: the $2{}^3{S}_1$, $2{}^1{S}_0$, $1{}^3{D}_1$, $1{}^3{D}_3$ and two $1D_2$ states. Observing some of the missing states would help confirm the nature of the $D_{s1}^{*}(2710)$ and $D_{sJ}^{*}(2860)$ states.

We consider the contribution of the extra sterile states in generic low-scale seesaw models to extra radiation, parametrized by $N_{\text{eff}}$. We find that the value of $N_{\text{eff}}$ is roughly independent of the seesaw scale within a wide range. We explore the full parameter space in the case of two extra sterile states and find that these models are strongly constrained by cosmological data for any value of the seesaw scale below $\mathcal{O}(100\mathrm{MeV})$.

We report measurements of branching fractions of $\tau$ lepton decays to final states with a $K_S^0$ meson using a $669{\mathrm{fb}}^{-1}$ data sample accumulated with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. The inclusive branching fraction is measured to be $\mathcal{B}({\tau }^{-}\to K_S^0{X}^{-}{\nu }_{\tau })=(9.15\pm 0.01\pm 0.15)\times 10^{-3}$, where $X^{-}$ can be anything; the exclusive branching fractions are $\mathcal{B}({\tau }^{-}\to {\pi }^{-}{K}_S^0{\nu }_{\tau })=(4.16\pm 0.01\pm 0.08)\times 10^{-3}$, $\mathcal{B}({\tau }^{-}\to K^{-}{K}_S^0{\nu }_{\tau })=(7.40\pm 0.07\pm 0.27)\times 10^{-4}$, $\mathcal{B}({\tau }^{-}\to {\pi }^{-}{K}_S^0{\pi }^0{\nu }_{\tau })=(1.93\pm 0.02\pm 0.07)\times 10^{-3}$, $\mathcal{B}({\tau }^{-}\to K^{-}{K}_S^0{\pi }^0{\nu }_{\tau })=(7.48\pm 0.10\pm 0.37)\times 10^{-4}$, $\mathcal{B}({\tau }^{-}\to {\pi }^{-}{K}_S^0{K}_S^0{\nu }_{\tau })=(2.33\pm 0.03\pm 0.09)\times 10^{-4}$, $\mathcal{B}({\tau }^{-}\to {\pi }^{-}{K}_S^0{K}_S^0{\pi }^0{\nu }_{\tau })=(2.00\pm 0.22\pm 0.20)\times 10^{-5}$, where the first uncertainty is statistical and the second is systematic. For each mode, the accuracy is improved over that of pre-$B$-factory measurements by a factor ranging from five to ten. In ${\tau }^{-}\to {\pi }^{-}{K}_S^0{K}_S^0{\pi }^0{\nu }_{\tau }$ decays, clear signals for the intermediate states ${\tau }^{-}\to {\pi }^{-}{f}_1(1285){\nu }_{\tau }$ and ${\tau }^{-}\to K^{*-}{K}_S^0{\pi }^0{\nu }_{\tau }$ are observed.

We investigate the feasibility of directly detecting a generation mechanism of the cosmic baryon asymmetry by repeating the same particle physics process inside the LHC. We propose a framework with $R$-parity and $CP$ violating squark decays responsible for baryogenesis, which can be embedded in supersymmetric models and is partly motivated by naturalness. We argue that the baryon number generation here is closely related to lepton charge asymmetry on the resonance. We emphasize the importance of the single charged lepton plus multijet channel in the absence of significant missing energy in search of such a scenario.

A facility that can deliver beams of electron and muon neutrinos from the decay of a stored muon beam has the potential to unambiguously resolve the issue of the evidence for light sterile neutrinos that arises in short-baseline neutrino oscillation experiments and from estimates of the effective number of neutrino flavors from fits to cosmological data. In this paper, we show that the nuSTORM facility, with stored muons of $3.8\mathrm{GeV}/\mathrm{c}\pm 10\%$, will be able to carry out a conclusive muon neutrino appearance search for sterile neutrinos and test the LSND and MiniBooNE experimental signals with $10\sigma$ sensitivity, even assuming conservative estimates for the systematic uncertainties. This experiment would add greatly to our knowledge of the contribution of light sterile neutrinos to the number of effective neutrino flavors from the abundance of primordial helium production and from constraints on neutrino energy density from the cosmic microwave background. The appearance search is complemented by a simultaneous muon neutrino disappearance analysis that will facilitate tests of various sterile neutrino models.

A search for the rare decays of $J/\psi \to D_s^{-}{\rho }^{+}+\mathrm{c}.\mathrm{c}.$ and $J/\psi \to {\overline{D}}^0{\overline{K}}^{*0}+\mathrm{c}.\mathrm{c}.$ is performed with a data sample of 225.3-million $J/\psi$ events collected with the Beijing Spectrometer III detector. No evident signal is observed. Upper limits on the branching fractions are determined to be $\mathcal{B}(J/\psi \to D_s^{-}{\rho }^{+}+\mathrm{c}.\mathrm{c}.)<1.3\times {10}^{-5}$ and $\mathcal{B}(J/\psi \to {\overline{D}}^0{\overline{K}}^{*0}+\mathrm{c}.\mathrm{c}.)<2.5\times {10}^{-6}$ at the 90% confidence level.

We present an exact and close-form harmonic metric for Kerr-Newman black hole, and demonstrate it is unique in the harmonic coordinates.

We embed spherical Rindler space—a geometry with a spherical hole in its center—in asymptotically anti– de Sitter (AdS) spacetime and show that it carries a gravitational entropy proportional to the area of the hole. Spherical AdS-Rindler space is holographically dual to an ultraviolet sector of the boundary field theory given by restriction to a strip of finite duration in time. Because measurements have finite durations, local observers in the field theory can only access information about bounded spatial regions. We propose a notion of differential entropy that captures uncertainty about the state of a system left by the collection of local, finite-time observables. For two-dimensional conformal field theories we use holography and the strong subadditivity of entanglement to propose a formula for differential entropy and show that it precisely reproduces the areas of circular holes in ${\mathrm{AdS}}_3$. Extending the notion to field theories on strips with variable durations in time, we show more generally that differential entropy computes the areas of all closed, inhomogeneous curves on a spatial slice of ${\mathrm{AdS}}_3$. We discuss the extension to higher-dimensional field theories, the relation of differential entropy to entanglement between scales, and some implications for the emergence of space from the renormalization group flow of entangled field theories.

We obtain exact traveling-wave solutions of the coupled nonlinear partial differential equations that describe the dynamics of two classical scalar fields in $1+1$ dimensions. The solutions are kinks interpolating between neighboring vacua. We compute the classical kink mass and show that it saturates a Bogomol’nyi-type bound. We also present exact traveling-wave solutions of a more general class of models. Examples include coupled ${\varphi }^4$ and sine-Gordon models.

We formulate a generic $\mathcal{N}=2$ three-dimensional superfield higher-derivative gauge theory coupled to the matter, which, in certain cases reduces to the $\mathcal{N}=2$ three-dimensional scalar super-QED, or supersymmetric Maxwell-Chern-Simons or Chern-Simons theories with matter. For this theory, we explicitly calculate the one-loop effective potential.

We report the construction of a three-dimensional template bank for the search for gravitational waves from inspiralling binaries consisting of spinning compact objects. The parameter space consists of two dimensions describing the mass parameters and one “reduced-spin” parameter, which describes the secular (nonprecessing) spin effects in the waveform. The template placement is based on an efficient stochastic algorithm and makes use of the semianalytical computation of a metric in the parameter space. We demonstrate that for “low-mass” ($m_1+m_2\lesssim 12M_{\odot }$) binaries, this template bank achieves effective fitting factors $\sim 0.92–0.99$ towards signals from generic spinning binaries in the advanced detector era over the entire parameter space of interest (including binary neutron stars, binary black holes, and black-hole neutron-star binaries). This provides a powerful and viable method for searching for gravitational waves from generic spinning low-mass compact binaries. Under the assumption that spin magnitudes of black holes (neutron stars) are uniformly distributed between 0–0.98 [0–0.4] and spin angles are isotropically distributed, the expected improvement in the average detection volume (at a fixed signal-to-noise-ratio threshold) of a search using this reduced-spin bank is $\sim 20\%–52\%$, as compared to a search using a nonspinning bank.