In this work we study a scenario with a warped five-dimensional smooth braneworld with four-dimensional (4D) Minkowski geometry built from bulk scalar matter nonminimally coupled to gravity with an additional Gauss-Bonnet term. We present exact solutions for the full braneworld configuration in contrast to previous results where only approximate solutions were constructed due to the highly nonlinear character of the relevant differential equations. These solutions allow us to study the necessary conditions for the finiteness of the 4D Planck mass and, additionally, enable us to perform a more rigorous analysis of 4D gravity localization compared to approximate approaches. It is remarkable that all the constructed braneworld configurations lead to standard 4D gravity localization since they contain a localized massless tensor mode (the graviton). We also analyze the localization properties of scalar, vector, and tensor fluctuation modes for the constructed field configurations. We show that for the considered backgrounds, only the massless tensor mode, i.e., the 4D graviton, is localized on the brane, while the vector and scalar modes are not confined to the brane.

We compute the vacuum energy for Kerr black holes with anti–de Sitter (AdS) asymptotics in dimensions $5\le D\le 9$ with all rotation parameters. The calculations are carried out employing an alternative regularization scheme for asymptotically AdS gravity, which considers supplementing the bulk action with counterterms which are a given polynomial in the extrinsic and intrinsic curvatures of the boundary (also known as Kounterterms). The Kerr-Schild form of the rotating solutions enables us to identify the vacuum energy as coming from the part of the metric that corresponds to a global AdS spacetime written in oblate spheroidal coordinates. We find that the zero-point energy for higher-dimensional Kerr-AdS reduces to one of a Schwarzschild-AdS black hole when all the rotation parameters are equal to each other, a fact that is well known in five dimensions. We also sketch a compact expression for the vacuum energy formula in terms of asymptotic quantities that might be useful to extend the computations to higher odd dimensions.

We present an explicit integration of the kink soliton equation obtained in a recent interesting study of the classical Skyrme model where the field configurations are of a generalized hedgehog form which is of a domain-wall type. We also show that in such a reduced one-dimensional setting the first-order and second-order equations are equivalent. Consequently, in such a context, all finite-energy solitons are Bogomolnyi-Prasad-Sommerfield type and precisely known.

Calculations of the gravitational self-force (GSF) on a point mass in curved spacetime require as input the metric perturbation in a sufficiently regular gauge. A basic challenge in the program to compute the GSF for orbits around a Kerr black hole is that the standard procedure for reconstructing the metric perturbation is formulated in a class of “radiation” gauges, in which the particle singularity is nonisotropic and extends away from the particle’s location. Here we present two practical schemes for calculating the GSF using a radiation-gauge reconstructed metric as input. The schemes are based on a detailed analysis of the local structure of the particle singularity in the radiation gauges. We show that three types of radiation gauge exist: two containing a radial stringlike singularity emanating from the particle, either in one direction (“half-string” gauges) or both directions (“full-string” gauges); and a third type containing no strings but with a jump discontinuity (and possibly a delta function) across a surface intersecting the particle. Based on a flat-space example, we argue that the standard mode-by-mode reconstruction procedure yields the “regular half” of a half-string solution, or (equivalently) either of the regular halves of a no-string solution. For the half-string case, we formulate the GSF in a locally deformed radiation gauge that removes the string singularity near the particle. We derive a mode-sum formula for the GSF in this gauge, which is analogous to the standard Lorenz-gauge formula but requires a correction to the values of the regularization parameters. For the no-string case, we formulate the GSF directly, without a local deformation, and we derive a mode-sum formula that requires no correction to the regularization parameters but involves a certain averaging procedure. We explain the consistency of our results with Gralla’s invariance theorem for the regularization parameters, and we discuss the correspondence between our method and a related approach by Friedman et al.

If the entire post-inflationary patch is large compared to our Hubble volume even a small level of non-Gaussianity can cause statistics of the primordial curvature field in our Hubble volume to be biased by mode coupling. We explicitly compute the variation of locally measured statistics of the primordial curvature $\zeta$ from non-Gaussian mode coupling within a specific inflationary scenario: the curvaton model with a quadratic curvaton potential. This “super cosmic variance" is calculated in two ways: (i) as a super observer who has access to the curvature perturbation field across the entire post-inflationary patch and therefore sees local statistics as biased by mode coupling and (ii) as a local observer who sees the statistics of $\zeta$ determined by the local values of quantities in their Hubble patch. The two calculations agree and show that in the quadratic curvaton model patch-to-patch differences in statistics of $\zeta$ can be interpreted entirely as a shift in the value of the curvaton field at freeze out. Applying the same arguments to single-field slow-roll inflation gives a simple picture of how non-Gaussian mode coupling between the curvature perturbations on very different physical scales must vanish in the attractor limit.

Cosmological perturbation theory is the theory of fluctuations (scalar as well as tensor) around the inflationary cosmological background solution. It is important to understand the details of the process of renormalization in this theory. In more familiar applications of quantum field theory, the dependence on the external momenta of the dimensionally regulated expression of the one-loop contribution to a correlator determines the number of counterterms (and their forms) required to renormalize it. In this work, it is pointed out that in cosmological perturbation theory, though this still happens, it happens in a completely different way such that in the late time limit, the information about the number and forms of counterterms required gets erased. This is to be compared with what happens in spontaneous symmetry breaking where the use of fluctuation fields around a chosen vacuum seems to suggest that more counterterms are needed to renormalize the theory than are actually required. We also comment on how the field strength of curvature perturbation, $\zeta$, could get renormalized.

The standard concordance model of the Universe is based on the cosmological constant as the driver of accelerating expansion. This concordance model is being subjected to a growing range of interlocking observations. In addition to using generic observational tests, one can also design tests that target the specific properties of the cosmological constant. These null tests do not rely on parametrizations of observables, but focus on quantities that are constant only if dark energy is a cosmological constant. We use supernova data in null tests that are based on the luminosity distance. In order to extract derivatives of the distance in a model-independent way, we use Gaussian processes. We find that the concordance model is compatible with the Union 2.1 data, but the error bars are fairly large. Simulated data sets are generated for the Dark Energy Survey supernova survey and we show that this survey will allow for a sharper null test of the cosmological constant if we assume the Universe is flat. Allowing for spatial curvature degrades the power of the null test.

A mechanism of the creation of stellarlike objects in the very early universe, from the QCD phase transition until big bang nucleosynthesis and somewhat later, is studied. It is argued that in the considered process, primordial black holes with masses above a few solar masses up to superheavy ones could be created. This may explain an early quasar creation with evolved chemistry in surrounding medium and the low mass cutoff of the observed black holes. It is also shown that dense primordial stars can be created at the considered epoch. Such stars could later become very early supernovae and, in particular, high redshift gamma bursters. In a version of the model, some of the created objects can consist of antimatter.

Trapped ultracold neutrons (UCNs) have for many years been the mainstay of experiments to search for the electric dipole moment (EDM) of the neutron, a critical parameter in constraining scenarios of new physics beyond the Standard Model. Because their energies are so low, UCNs preferentially populate the lower region of their physical enclosure and do not sample uniformly the ambient magnetic field throughout the storage volume. This leads to a substantial increase in the rate of depolarization, as well as to shifts in the measured frequency of the stored neutrons. Consequences for EDM measurements are discussed.

We consider the sign problem for classical spin models at complex $\beta =1/g_0^2$ on $L\times L$ lattices. We show that the tensor renormalization group method allows reliable calculations for larger Im$\beta$ than the reweighting Monte Carlo method. For the Ising model with complex $\beta$ we compare our results with the exact Onsager-Kaufman solution at finite volume. The Fisher zeros can be determined precisely with the tensor renormalization group method. We check the convergence of the tensor renormalization group method for the $O(2)$ model on $L\times L$ lattices when the number of states $D_s$ increases. We show that the finite size scaling of the calculated Fisher zeros agrees very well with the Kosterlitz-Thouless transition assumption and predict the locations for larger volume. The location of these zeros agree with Monte Carlo reweighting calculation for small volume. The application of the method for the $O(2)$ model with a chemical potential is briefly discussed.

Recently LHCb has announced a discrepancy of $3.7\sigma$ in one of the theoretically clean observables accessible through studies of angular correlations in $B\to K^{*}{\mu }^{+}{\mu }^{-}$. We point out that in the most minimal $Z^{\prime }$ setup that can address this anomaly there is a model-independent triple correlation between new physics (NP) in $B\to K^{*}{\mu }^{+}{\mu }^{-}$, $B_s-{\overline{B}}_s$ mixing, and nonunitarity of the quark-mixing matrix. This triple correlation can be cast into a simple analytic formula that relates the NP contribution $\mathrm{\Delta }{C}_9$ to the Wilson coefficient of the semileptonic vector operator to a shift in the mass difference $\mathrm{\Delta }{M}_{B_s}$ and a violation of ${|V_{ud}|}^2+{|V_{us}|}^2+{|V_{ub}|}^2=1$. In contrast to the individual observables the found relation depends only logarithmically on the $Z^{\prime }$ mass. We show that our findings allow for useful future tests of the pattern of NP suggested by the $B\to K^{*}{\mu }^{+}{\mu }^{-}$ anomaly.

We study the covariant version of the quark-parton model, in which the general rules of the angular momentum composition are accurately taken into account. We demonstrate how these rules affect the relativistic interplay between the quark spins and orbital angular momenta, which collectively contribute to the proton spin. The spin structure functions $g_1$ and $g_2$, corresponding to the many-quark state $J=1/2$, are studied, and it is shown they satisfy constraints and relations, which fit well the available experimental data including the data on proton spin content $\mathrm{\Delta }\mathrm{\Sigma }\lesssim 1/3$. The suggested Lorentz-invariant three-dimensional approach for calculation of the structure functions is compared with the approach based on the conventional collinear parton model.

We derive the higher twist (four and five) nucleon distribution amplitudes in the Wandzura-Wilczek approximation. Our method is based on an analysis of the conformal expansion of nonlocal operators in the spinor formalism.

We consider the problem of “measuring” the Källén-Lehmann spectral density of a particle (be it elementary or bound state) propagator by means of 4D lattice data. As the latter are obtained from operations at (Euclidean momentum squared) $p^2\ge 0$, we are facing the generically ill-posed problem of converting a limited data set over the positive real axis to an integral representation, extending over the whole complex $p^2$ plane. We employ a linear regularization strategy, commonly known as the Tikhonov method with the Morozov discrepancy principle, with suitable adaptations to realistic data, e.g. with an unknown threshold. An important virtue over the (standard) maximum entropy method is the possibility to also probe unphysical spectral densities, for example, of a confined gluon. We apply our proposal here to “physical” mock spectral data as a litmus test and then to the lattice $SU(3)$ Landau gauge gluon at zero temperature.

The next-to-leading order QCD corrections to $W^{\pm }\gamma$ production in association with two jets via vector boson fusion are calculated, including the leptonic decay of the $W$ with full off-shell effects and spin correlations. The process lends itself to a test of quartic gauge couplings. The next-to-leading order corrections reduce the scale uncertainty significantly and show a nontrivial phase space dependence.

In our previous work [ , Phys. Rev. D 88, 074021 (2013)], it has been found that sizable charmonium events can be produced via the channel ${\mathit{e}}^{+}{e}^{-}\to {\gamma }^{*}/Z^0\to H(|c\overline{c}⟩)+\gamma$ at the suggested super $Z$ factory, where $H(|c\overline{c}⟩)$ represents the dominant color-singlet $S$-wave and $P$-wave charmonium states $J/\psi$, ${\eta }_c$, $h_c$ and ${\chi }_{cJ}$ ($J=0$, 1, 2), respectively. As an important step forward, in the present paper, we present a next-to-leading order (NLO) QCD analysis within the framework of nonrelativistic QCD. Different from the case of $B$ factory in which the single charmonium production is dominated by the channel via a virtual photon, at the super $Z$ factory, its cross section is dominated by the channel via a $Z^0$ boson. Estimations up to NLO level are done under the condition of both the $B$ factory and the super $Z$ factory. We observe that the NLO distributions have the same shapes as those of LO distributions, but their differences are sizable. This indicates that a NLO calculation is necessary and important to achieve a more accurate estimation. Due to the $Z^0$ boson resonance effect, at the super $Z$ factory with a high luminosity up to $10^{36}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$, when summing all the color-singlet states’ contributions together, one may observe about $8.0\times 10^4$ charmonium events via the channel $e^{+}{e}^{-}\to Z^0\to H(|c\overline{c}⟩)+\gamma$ in one operation year. Then, such a super $Z$ factory could provide another useful platform to study the charmonium properties, even for the higher charmonium states.

Proposed medium-baseline reactor neutrino experiments offer unprecedented opportunities to probe, at the same time, the mass-mixing parameters which govern ${\nu }_e$ oscillations both at long wavelength ($\delta m^2$ and ${\theta }_{12}$) and at short wavelength ($\mathrm{\Delta }{m}^2$ and ${\theta }_{13}$), as well as their tiny interference effects related to the mass hierarchy (i.e., the relative sign of $\mathrm{\Delta }{m}^2$ and $\delta m^2$). In order to take full advantage of these opportunities, precision calculations and refined statistical analyses of event spectra are required. In such a context, we revisit several input ingredients, including nucleon recoil in inverse beta decay and its impact on energy reconstruction and resolution, hierarchy and matter effects in the oscillation probability, spread of reactor distances, irreducible backgrounds from geoneutrinos and from far reactors, and degeneracies between energy scale and spectrum shape uncertainties. We also introduce a continuous parameter $\alpha$, which interpolates smoothly between normal hierarchy ($\alpha =+1$) and inverted hierarchy ($\alpha =-1$). The determination of the hierarchy is then transformed from a test of hypothesis to a parameter estimation, with a sensitivity given by the distance of the true case (either $\alpha =+1$ or $\alpha =-1$) from the “undecidable” case ($\alpha =0$). Numerical experiments are performed for the specific setup envisaged for the JUNO project, assuming a realistic sample of $O({10}^5)$ reactor events. We find a typical sensitivity of $\sim 2\sigma$ to the hierarchy in JUNO, which, however, can be challenged by energy scale and spectrum shape systematics, whose possible conspiracy effects are investigated. The prospective accuracy reachable for the other mass-mixing parameters is also discussed.

We find evidence for the semileptonic baryonic decay $B^{-}\to p\overline{p}{\ell }^{-}{\overline{\nu }}_{\ell }$ ($\ell =e$, $\mu$), based on a data sample of 772 million $B\overline{B}$ pairs collected at the $\mathrm{\Upsilon }(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy electron-positron collider. A neural-network based hadronic $B$-meson tagging method is used in this study. The branching fraction of $B^{-}\to p\overline{p}{\ell }^{-}{\overline{\nu }}_{\ell }$ is measured to be $(5.8_{-2.1}^{+2.4}\text{(stat)}\pm 0.9\text{(syst)})\times {10}^{-6}$ with a significance of $3.2\sigma$, where lepton universality is assumed. We also estimate the corresponding upper limit: $\mathcal{B}(B^{-}\to p\overline{p}{\ell }^{-}{\overline{\nu }}_{\ell })<9.6\times {10}^{-6}$ at the 90% confidence level. This measurement helps constrain the baryonic transition form factor in $B$ decays.