We study the processes $e^{+}{e}^{-}\to K_S^0{K}_L^0\gamma$, $K_S^0{K}_L^0{\pi }^{+}{\pi }^{-}\gamma$, $K_S^0{K}_S^0{\pi }^{+}{\pi }^{-}\gamma$, and $K_S^0{K}_S^0{K}^{+}{K}^{-}\gamma$, where the photon is radiated from the initial state, providing cross section measurements for the hadronic states over a continuum of center-of-mass energies. The results are based on $469{\text{fb}}^{-1}$ of data collected with the BABAR detector at SLAC. We observe the $\varphi (1020)$ resonance in the $K_S^0{K}_L^0$ final state and measure the product of its electronic width and branching fraction with about 3% uncertainty. We present a measurement of the $e^{+}{e}^{-}\to K_S^0{K}_L^0$ cross section in the energy range from 1.06 to 2.2 GeV and observe the production of a resonance at 1.67 GeV. We present the first measurements of the $e^{+}{e}^{-}\to K_S^0{K}_L^0{\pi }^{+}{\pi }^{-}$, $K_S^0{K}_S^0{\pi }^{+}{\pi }^{-}$, and $K_S^0{K}_S^0{K}^{+}{K}^{-}$ cross sections and study the intermediate resonance structures. We obtain the first observations of $J/\psi$ decay to the $K_S^0{K}_L^0{\pi }^{+}{\pi }^{-}$, $K_S^0{K}_S^0{\pi }^{+}{\pi }^{-}$, and $K_S^0{K}_S^0{K}^{+}{K}^{-}$ final states.

When measuring the one-dimensional (1D) power spectrum of the Lyman-$\alpha$ ($\mathrm{Ly}\alpha$) forest, it is common to measure the power spectrum in the flux fluctuations redward of the $\mathrm{Ly}\alpha$ emission of quasars, and to subtract this power from the measurements of the $\mathrm{Ly}\alpha$ flux power spectrum. This removes the excess power present in the $\mathrm{Ly}\alpha$ forest, which is believed to be dominated by metal absorption of low-redshift metals uncorrelated with the neutral hydrogen absorbtion in $\mathrm{Ly}\alpha$. In this paper we note that, assuming the contaminants are additive in the optical depth, the correction contains a second-order term. We estimate the magnitude of this term for two currently published measurements of the 1D $\mathrm{Ly}\alpha$ flux power spectrum and show that it is negligible for the current generation of measurements. However, future measurements must take this effect into account when the error bars improve by a factor of 2 or more.

In string bit models, the superstring emerges as a very long chain of “bits,” in which $s$ fermionic degrees of freedom contribute positively to the ground state energy in a way to exactly cancel the destabilizing negative contributions of $d=s$ bosonic degrees of freedom. We propose that the physics of string formation be studied nonperturbatively in the class of string bit models in which $s>d$, so that a long chain is stable, in contrast to the marginally stable ($s=d=8$) superstring chain. We focus on the simplest of these models with $s=1$ and $d=0$, in which the string bits live in zero space dimensions. The string bit creation operators are $N\times N$ matrices. We choose a Hamiltonian such that the large $N$ limit produces a string moving in one space dimension, with excitations corresponding to one Grassmann light-cone world sheet field ($s=1$) and no bosonic world sheet field ($d=0$). We study this model at finite $N$ to assess the role of the large $N$ limit in the emergence of the spatial dimension. Our results suggest that stringlike states with large bit number $M$ may not exist for $N\le (M-1)/2$. If this is correct, one can have finite chains of string bits, but not a continuous string, at finite $N$. Only for extremely large $N$ can such chains behave approximately like a continuous string, in which case there will also be the (approximate) emergence of a new spatial dimension. In string bit models designed to produce a critical superstring at $N=\infty$, we can then expect only approximate Lorentz invariance at finite $N$, with violations of order $1/N^2$.

We investigate the classical stability of Schwarzschild black hole in Jordan and Einstein frames that are related by the conformal transformations. For this purpose, we introduce two models of the Brans-Dicke theory and Brans-Dicke-Weyl gravity in the Jordan frame and two corresponding models in the Einstein frame. The former model is suitable for studying the massless spin-2 graviton propagating around the Schwarzschild black hole, while the latter is designed for the massive spin-2 graviton propagating around the black hole. It turns out that the black hole (in)stability is independent of the frame which shows that the two frames are equivalent to each other.

We study gravitational curvature effects in circular and radial geodesics in static, spherically symmetric space-times, using Fermi normal coordinates. We first set up these coordinates in the general case, and then use this to study effective magnetic fields due to gravitational curvature in the exterior and interior Schwarzschild, Janis-Newman-Winicour, and Bertrand space-times. We show that these fields can be large for specific parameter values in the theories, and thus might have observational significance. We discuss the qualitative differences of the magnetic field for vacuum space-times and for those seeded by matter. We estimate the magnitude of these fields in realistic galactic scenarios and discuss their possible experimental relevance. Gravitational curvature corrections to the hydrogen atom spectrum for these space-times are also discussed briefly.

We study the bispectrum of matter density perturbations induced by the large-scale structure formation in the most general second-order scalar-tensor theory that may possess the Vainshtein mechanism as a screening mechanism. On the basis of the standard perturbation theory, we derive the bispectrum being expressed by a kernel of the second-order density perturbations. We find that the leading-order kernel is characterized by one parameter, which is determined by the solutions of the linear density perturbations, the Hubble parameter, and the other function specifying nonlinear interactions. This is because our model, which may be equipped with the Vainshtein mechanism, includes only one simple function that describes mode couplings of the nonlinear interactions. This feature does not allow for varied behavior in the bispectrum of the matter density perturbations in the most general second-order scalar-tensor theory equipped with the Vainshtein mechanism. We exemplify the typical behavior of the bispectrum in a kinetic gravity braiding model.

We study gravitational perturbations sourced by a rotating test shell collapsing into five-dimensional Myers-Perry black holes in anti-de Sitter (AdS). Our attention is restricted to the case in which the two possible angular momenta of the geometry are set equal. In this situation the background is cohomogeneity-1, which amounts to a crucial technical simplification. It is found that the linearized Einstein equations are consistent only when the test shell is corotating with the spacetime. However, it is argued that this is a consequence of the matter on the shell being described by dust or, more precisely, noninteracting test particles. We compute the mass and angular momenta of the perturbed spacetime using a counterterm subtraction method, for which we provide an explicit formula that has not appeared previously in the literature. The results are in agreement with the expected expressions for energy and angular momenta of geodesic particles in ${\mathrm{AdS}}_5$.

Cosmography is used in cosmological data processing in order to constrain the kinematics of the universe in a model-independent way, providing an objective means to evaluate the agreement of a model with observations. In this paper, we extend the conventional methodology of cosmography employing Taylor expansions of observables by an alternative approach using Padé approximations. Due to the superior convergence properties of Padé expansions, it is possible to improve the fitting analysis to obtain numerical values for the parameters of the cosmographic series. From the results, we can derive the equation of state parameter of the universe and its first derivative and thus acquire information about the thermodynamic state of the universe. We carry out statistical analyses using observations of the distance modulus of type 1a supernovae, provided by the union 2.1 compilation of the supernova cosmology project, employing a Markov chain Monte Carlo approach with an implemented Metropolis algorithm. We compare the results of the original Taylor approach to the newly introduced Padé formalism. The analyses show that experimental data constrain the observable universe well, finding an accelerating universe and a positive jerk parameter. We demonstrate that the Padé convergence radii are greater than standard Taylor convergence radii, and infer a lower limit on the acceleration of the universe solely by requiring the positivity of the Padé expansion. We obtain fairly good agreement with the Planck results, confirming the $\mathrm{\Lambda }\mathrm{CDM}$ model at small redshifts, although we cannot exclude a dark energy density varying in time with negligible speed of sound.

We present the strongest current cosmological upper limit on the neutrino mass of $\sum m_{\nu }<0.18\mathrm{eV}$ (95% confidence). It is obtained by adding observations of the large-scale matter power spectrum from the WiggleZ Dark Energy Survey to observations of the cosmic microwave background data from the Planck surveyor, and measurements of the baryon acoustic oscillation scale. The limit is highly sensitive to the priors and assumptions about the neutrino scenario. We explore scenarios with neutrino masses close to the upper limit (degenerate masses), neutrino masses close to the lower limit where the hierarchy plays a role, and the addition of massive or massless sterile species.

We investigate the production of antideuterons from decaying dark matter, using gravitinos in supersymmetric models with trilinear $R$-parity-violating (RPV) operators as an example. The model used for antideuteron formation is shown to induce large uncertainties in the predicted flux, comparable to uncertainties from cosmic-ray propagation models. We improve on the formation model by tuning hadronization and coalescence parameters in Monte Carlo simulations to better reproduce the hadron spectra relevant for antideuteron production. In light of current bounds on fluxes and future prospects from the AMS-02 and GAPS experiments we set limits on RPV couplings as a function of the gravitino mass.

Recent IceCube results suggest that the first detection of very high energy astrophysical neutrinos have been accomplished. We consider these results at face value in a Galactic origin context. Emission scenarios from both the Fermi bubble and broader halo region are considered. We motivate that such an intensity of diffuse neutrino emission could be Galactic in origin if it is produced from an outflow into the halo region. This scenario requires cosmic ray transport within the outflow environment to be different to that inferred locally within the disk and that activity in the central part of the Galaxy accelerates cosmic rays to trans-“knee” energies before they escape into an outflow. The presence of a large reservoir of gas in a very extended halo around the Galaxy, recently inferred from x-ray observations, implies that the relatively modest acceleration power of $10^{39}$ erg ${\mathrm{s}}^{-1}$ in PeV energy cosmic rays may be sufficient to explain the observed neutrino flux. Such a luminosity is compatible with that required to explain the observed intensity of cosmic rays around the knee.

We present a self-consistent interpretation of the very high-energy neutrino signal from the direction of the inner Galaxy, which is a part of the astronomical neutrino signal reported by IceCube. We demonstrate that an estimate of the neutrino flux in the $E>100\mathrm{TeV}$ energy range lies at the high-energy power-law extrapolation of the spectrum of diffuse $\gamma$-ray emission from the galactic ridge, as observed by the Fermi telescope. This suggests that IceCube neutrino and Fermi/LAT $\gamma$-ray fluxes are both produced in interactions of cosmic rays with the interstellar medium in the Norma arm and/or in the galactic bar. Cosmic rays responsible for the ($\gamma$ ray) and neutrino flux are characterized by a hard spectrum with the slope harder than $-2.4$ and cutoff energy higher than 10 PeV.

We investigate a class of theories where the mass of the lightest Higgs boson of the minimal supersymmetric standard model (MSSM) can be larger than the Z gauge boson mass at tree level. In this context the MSSM fields feel a new force, whose corresponding gauge boson attains its mass through the Stueckelberg mechanism. We show how one can achieve a Higgs mass around 126 GeV without assuming a heavy stop spectrum or a large stop trilinear term. The application of this class of models to the conservation of R parity is also discussed.

Only phase space is typically used to obtain final-state particle spectra in rare decay searches, which is a crude approximation in the case of three-body processes. We will demonstrate how both dynamics and phase space can be approximately accounted for in processes originating from grand unification models—such as nucleon decays $p\to e^{+}\overline{\nu }\nu$ or $p\to {\mu }^{+}\overline{\nu }\nu$—using the general effective Fermi theory formalism of electroweak muon decay, $\mu \to e^{+}\overline{\nu }\nu$. This approach allows for a more precise and only weakly model-dependent approximation of final particle spectra for these and similar decays, which may improve rare process searches in current and near-future experiments.

The rare decays $B^0\to K^{*0}{\mu }^{+}{\mu }^{-}$ and $B_s\to \varphi {\mu }^{+}{\mu }^{-}$ are now being observed with enough precision to test Standard Model predictions. A full understanding of these decays requires accurate determinations of the corresponding hadronic form factors. Here we present results of lattice QCD calculations of the $B\to K^{*}$ and $B_s\to \varphi$ form factors. We also determine the form factors relevant for the decays $B_s\to K^{*}\ell \nu$ and $B_s\to {\overline{K}}^{*0}{\ell }^{+}{\ell }^{-}$. We use full-QCD configurations including $2+1$ flavors of sea quarks using an improved staggered action, and we employ lattice nonrelativistic QCD to describe the bottom quark.

In this paper, we calculate the next-to-leading-order (NLO) twist-3 contribution to the form factors of $B\to \pi$ transitions by employing the $k_T$ factorization theorem. All the infrared divergences regulated by the logarithms $\ln (k_{iT}^2)$ cancel between those from the quark diagrams and from the effective diagrams for the initial $B$ meson wave function and the final pion meson wave function. An infrared finite NLO hard kernel is, therefore, obtained, which confirms the application of the $k_T$ factorization theorem to the $B$ meson semileptonic decays at the twist-3 level. From our analytical and numerical evaluations, we find that the NLO twist-3 contributions to the form factors $f^{+,0}(q^2)$ of the $B\to \pi$ transition are similar in size but have an opposite sign with the NLO twist-2 contribution, which leads to a large cancellation between these two NLO parts. For the case of $f^{+}(0)$, for example, the 24% NLO twist-2 enhancement to the full LO prediction is largely canceled by the negative (about $-17\%$) NLO twist-3 contribution, leaving a small and stable 7% enhancement to the full LO prediction in the whole range of $0\le q^2\le 12{\mathrm{GeV}}^2$. At the full NLO level, the perturbative QCD prediction is $F^{B\to \pi }(0)={0.269}_{-0.050}^{+0.054}$. We also study the possible effects on the perturbative QCD predictions when different sets of the $B$ meson and pion distribution amplitudes are used in the numerical evaluation.

We derive a semiclassical effective action and the kinetic equation for massive Dirac fermions in electromagnetic fields. The non-Abelian Berry phase structure emerges from two helicity states of massive fermions with positive energy. The classical spin emerges as a vector in SU(2) helicity space. The continuity equations for the fermion number and the classical spin are derived. The fermion number is conserved while the spin charge is not conserved by anomaly. Previous results about the coefficients of the chiral magnetic effect for the fermion and axial currents in the chiral limit can be reproduced after including the antifermion contributions. This provides an example for the emerging spin and non-Abelian Berry phase of Dirac fermions arising from the fermion mass.

In the QCD evolution of transverse momentum dependent parton distribution and fragmentation functions, the Collins-Soper evolution kernel includes both a perturbative short-distance contribution and a large-distance nonperturbative, but strongly universal, contribution. In the past, global fits, based mainly on larger $Q$ Drell-Yan–like processes, have found substantial contributions from nonperturbative regions in the Collins-Soper evolution kernel. In this article, we investigate semi-inclusive deep inelastic scattering measurements in the region of relatively small $Q$, of the order of a few GeV, where sensitivity to nonperturbative transverse momentum dependence may become more important or even dominate the evolution. Using recently available deep inelastic scattering data from the COMPASS experiment, we provide estimates of the regions of coordinate space that dominate in transverse momentum dependent (TMD) processes when the hard scale is of the order of only a few GeV. We find that distance scales that are much larger than those commonly probed in large $Q$ measurements become important, suggesting that the details of nonperturbative effects in TMD evolution are especially significant in the region of intermediate $Q$. We highlight the strongly universal nature of the nonperturbative component of evolution and its potential to be tightly constrained by fits from a wide variety of observables that include both large and moderate $Q$. On this basis, we recommend detailed treatments of the nonperturbative component of the Collins-Soper evolution kernel for future TMD studies.

The variations of muon flux that are occasionally registered by ground-based scintillation detectors during thunderstorms are investigated. The variations are mainly negative (deficit) and originate due to the electric field of thunderclouds. They last from several minutes up to several hours and demonstrate minor (up to a few percent) deviations against the background. We develop an appropriate theoretical model to describe this phenomenon by investigating the two processes responsible for it: (i) the transformation of an energetic spectrum of muons in the electric field due to their acceleration or deceleration, and (ii) the decay of muons conditioned by a short life span. The change of muon flux near the ground is derived at a given altitudinal distribution (profile) of the electric field. Two possible opposite cases of an altitudinal profile of a two-layered electric field are considered: (i) upward directed in the lower layer of the cloud and downward directed in the upper layer and (ii) vice versa. We find that in case (i), the deficit of muon fluxes is observed by the detector at any threshold energy. It emerges due to a decrease of the flux of positive muons decelerated in the lower layer of a thundercloud. The corresponding increase of the flux of accelerated muons turns out to be smaller because of their partial decaying. As a result, an uncompensated decrease of total flux of muons is formed near the ground. However, in case (ii), the deficit is smaller, and it may become positive when it is observed by detectors with a threshold energy larger than $\sim 300\mathrm{MeV}$. The results may help estimate the height and electric field of thunderclouds by analyzing the records of muon detectors with different energy thresholds.

We compare the charged-current quasielastic neutrino and antineutrino observables obtained in two different nuclear models, the phenomenological SuperScaling Approximation and the relativistic mean field approach, with the recent data published by the $\text{MINER}\nu \mathrm{A}$ Collaboration. Both models provide a good description of the data without the need of an ad hoc increase in the mass parameter in the axial-vector dipole form factor. Comparisons are also made with the MiniBooNE results, where different conclusions are reached.