The well-known Yang-Mills theory with one $S^1/Z_2$ universal extra dimension (UED) is generalized to an arbitrary number of spatial extra dimensions through a novel compactification scheme. In this paper, the Riemannian flat base manifold under consideration contains $n$ spatial extra dimensions defined by $n$ copies of the orbifold $S^1/Z_2$. In this approach, we present the gauge structure and the mass spectrum of the effective four-dimensional theory. We introduce the concept of standard and nonstandard gauge transformations of the effective theory, and explicitly identify the emergence of massive vector fields in the same number as massless (“pseudo-Goldstone”) scalars in the compactified theory, verifying that a Higgs-like mechanism operates in the compactification process. It is found that, in contrast with the one-UED scenario, in cases with two or more UEDs there emerge massive scalar fields. Besides, at the phase-space level, the Hamiltonian analysis yields that the higher-dimensional and compactified theories are classically equivalent using the fundamental concept of canonical transformation. This work lays the ground for a wider study on these theories concerning their quantization and predictive power at the level of quantum fluctuations.

The high-scale supersymmetry (SUSY) breaking scenario is now attracting many attentions, because it is consistent with almost all experiments of particle physics, astrophysics, and cosmology performed so far: e.g. it is possible to explain the Higgs mass of about 126 GeV and contains WIMP dark matter candidates. In the scenario, gauginos are predicted to be around the TeV scale, and thus within a kinematically accessible range of near future experiments. Calculation of the thermal relic abundance for gaugino (bino or wino) dark matter is then of particular importance in order to clarify its mass consistent with cosmology and to determine future directions for exploring the high-scale SUSY breaking scenario. In this article, we calculate the abundance of the gaugino dark matter, with especially focusing on various coannihilations between gauginos, which has not been extensively studied so far. Our calculation involves the Sommerfeld effect on wino and gluino annihilations, which is known to give significant contributions to their cross sections. Based on obtained results, we discuss some implications to gaugino searches at collider and indirect detection experiments of dark matter.

The inferred value of the relic density from cosmological observations has reached a precision that is akin to that of the LEP precision measurements. This level of precision calls for the evaluation of the annihilation cross sections of dark matter that goes beyond tree-level calculations as currently implemented in all codes for the computation of the relic density. In supersymmetry radiative corrections are known to be large and thus must be implemented. Full one-loop radiative corrections for many annihilation processes have been performed. It is important to investigate whether the bulk of these corrections can be parametrized through an improved Born approximation that can be implemented as a selection of form factors to a tree-level code. This paper is a second in a series that addresses this issue. After having provided these form factors for the annihilation of the neutralinos into fermions, which cover the case of a bino-like lightest supersymmetric particle (LSP), we turn our attention here to a higgsino-like dark matter candidate through its annihilation into $ZZ$. We also investigate the cases of a mixed LSP. In all cases we compare the performance of the form factor approach with the result of a full one-loop correction. We also study the issue of the renormalization scheme dependence. An illustration of the phenomenon of nondecoupling of the heavy sfermions that takes place for the annihilation of the lightest neutralino into $ZZ$ is also presented.

A study of the possible interactions between fermions assuming only rotational invariance has revealed 15 forms for the potential involving the fermion spins. We review the experimental constraints on unobserved macroscopic, spin-dependent interactions between electrons in the range below 1 cm. An existing experiment, using 1 kHz mechanical oscillators as test masses, has been used to constrain mass-coupled forces in this range. With suitable modifications, including spin-polarized test masses, this experiment can be used to explore all 15 possible spin-dependent interactions between electrons in this range with unprecedented sensitivity. Samples of ferrimagnetic dysprosium iron garnet have been fabricated in the suitable test mass geometry and shown to have spin densities on the order of ${10}^{20}\hslash /{\mathrm{cm}}^3$ with very low intrinsic magnetism.

We investigate the energy-momentum tensor form factors of the nucleon in a nuclear medium, based on an in-medium modified $\pi$-$\rho$-$\omega$ soliton model, with medium modifications of the mesons considered. The results allow us to establish general features of medium modifications of the structure of nucleons bound in a nuclear medium.

Two different techniques for adding additional data sets to existing global fits using Bayesian reweighting have been proposed in the literature. The derivation of each reweighting formalism is critically reviewed. A simple example is constructed that conclusively favors one of the two formalisms. The effects of this choice for global fits are discussed.

With $1.06\times {10}^8$ $\psi (3686)$ events collected with the BESIII detector, the branching fraction of $\psi (3686)\to \omega K^{+}{K}^{-}$ is measured to be $(1.54\pm 0.04\pm 0.11)\times 10^{-4}$. This is the most precise result to date, due to the largest $\psi (3686)$ sample, improved signal reconstruction efficiency, good simulation of the detector performance, and a more accurate knowledge of the continuum contribution. Using the branching fraction of $J/\psi \to \omega K^{+}{K}^{-}$, the ratio $\mathcal{B}(\psi (3868)\to K^{+}{K}^{-})/\mathcal{B}(J/\psi \to K^{+}{K}^{-})$ is determined to be $(18.4\pm 3.7)\%$. This constitutes a significantly improved test of the 12% rule, with the uncertainty now dominated by the $J/\psi$ branching fraction.

We present measurements of the inclusive production of antideuterons in $e^{+}{e}^{-}$ annihilation into hadrons at $\approx 10.58\mathrm{GeV}$ center-of-mass energy and in $\mathit{\Upsilon }(1S,2S,3S)$ decays. The results are obtained using data collected by the BABAR detector at the PEP-II electron-positron collider. Assuming a fireball spectral shape for the emitted antideuteron momentum, we find $\mathcal{B}(\mathit{\Upsilon }(1S)\to \overline{d}X)=(2.81\pm 0.49(\text{stat}{)}_{-0.24}^{+0.20}(\text{syst}))\times {10}^{-5}$, $\mathcal{B}(\mathit{\Upsilon }(2S)\to \overline{d}X)=(2.64\pm 0.11(\text{stat}{)}_{-0.21}^{+0.26}(\text{syst}))\times {10}^{-5}$, $\mathcal{B}(\mathit{\Upsilon }(3S)\to \overline{d}X)=(2.33\pm 0.15(\text{stat}{)}_{-0.28}^{+0.31}(\text{syst}))\times {10}^{-5}$, and $\sigma (e^{+}{e}^{-}\to \overline{d}X)=(9.63\pm 0.41(\text{stat}{)}_{-1.01}^{+1.17}(\text{syst})\mathrm{fb}$.

Five-dimensional $SU(3)$ gauge-Higgs unification models are studied at finite temperature in the warped extra dimension $S^1/{\mathbb{Z}}_2$. In order to investigate the phase structure, we develop a technique to compute the one-loop effective potential with the nontrivial Polyakov loop phase and with the nontrivial Wilson line phase along the extra dimension. Effective potentials as functions of two gauge-field condensations are shown for several simple matter contents, including fundamental, sextet, and adjoint representational Dirac fermions. Possible extensions and applications of our formalism are also briefly discussed.

Recent null results from LHC8 supersymmetry (SUSY) searches along with the discovery of a standard model (SM)–like Higgs boson with mass $m_h\simeq 125.5\mathrm{GeV}$ indicates sparticle masses in the TeV range, causing tension with conventional measures of electroweak fine-tuning. We propose a simple fine-tuning rule which should be followed under any credible evaluation of fine-tuning. We believe that overestimates of electroweak fine-tuning by conventional measures all arise from violations of this rule. We show that to gain accord with the fine-tuning rule, then both the Higgs mass and the traditional ${\mathrm{\Delta }}_{\mathrm{BG}}$ fine-tuning measures reduce to the model-independent electroweak fine-tuning measure ${\mathrm{\Delta }}_{\mathrm{EW}}$. This occurs by combining dependent contributions to $m_Z$ or $m_h$ into independent units. Then, using ${\mathrm{\Delta }}_{\mathrm{EW}}$, we evaluate EW fine-tuning for a variety of SUSY models including mSUGRA, NUHM1, NUHM2, mGMSB, mAMSB, hyper-charged AMSB, gaugino AMSB and nine cases of mixed moduli-anomaly (mirage) mediated SUSY breaking models while respecting LHC Higgs mass and $B$-decay constraints (we do not impose LHC8 sparticle mass constraints due to the possibility of compressed spectra within many of these models). We find mSUGRA, mGMSB and the AMSB models all to be highly fine-tuned. The NUHM1 model is moderately fine-tuned while NUHM2 which allows for radiatively driven naturalness (RNS) allows for fine-tuning at a meager 10% level in the case where $m(\text{Higgsinos})\sim 100–200\mathrm{GeV}$ and the TeV-scale top squarks are well mixed. Models with RNS may or may not be detectable at LHC14. A $\sqrt{s}\sim 500\mathrm{GeV}$ $e^{+}{e}^{-}$ collider will be required to make a definitive search for the requisite light Higgsinos.

We study the spectral dimension associated with diffusion processes on Euclidean $\kappa$-Minkowski space. We start by describing a geometric construction of the “Euclidean” momentum group manifold related to $\kappa$-Minkowski space. On such space we identify various candidate Laplacian functions, i.e. deformed Casimir invariants, and calculate the corresponding spectral dimension for each case. The results obtained show a variety of running behaviors for the spectral dimension according to the choice of deformed Laplacian, from dimensional reduction to superdiffusion.

Galactic neutron stars are a promising source of gravitational waves in the analysis band of detectors such as Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo. Previous searches for gravitational waves from neutron stars have focused on the detection of individual neutron stars, which are either nearby or highly nonspherical. Here, we consider the stochastic gravitational-wave signal arising from the ensemble of Galactic neutron stars. Using a population synthesis model, we estimate the single-sigma sensitivity of current and planned gravitational-wave observatories to average neutron star ellipticity $\epsilon$ as a function of the number of in-band Galactic neutron stars $N_{\text{tot}}$. For the plausible case of $N_{\text{tot}}\approx 53000$, and assuming one year of observation time with colocated initial LIGO detectors, we find it to be ${\sigma }_{\epsilon }=2.1\times {10}^{-7}$, which is comparable to current bounds on some nearby neutron stars. (The current best 95% upper limits are $\epsilon \lesssim 7\times {10}^{-8}$.) It is unclear if Advanced LIGO can significantly improve on this sensitivity using spatially separated detectors. For the proposed Einstein Telescope, we estimate that ${\sigma }_{\epsilon }=5.6\times {10}^{-10}$. Finally, we show that stochastic measurements can be combined with measurements of individual neutron stars in order to estimate the number of in-band Galactic neutron stars. In this way, measurements of stochastic gravitational waves provide a complementary tool for studying Galactic neutron stars.

The Planck mission has conclusively detected lensing of the cosmic microwave background (CMB) radiation from foreground sources to an overall significance of greater than $25\sigma$ [1]. The high precision of this measurement motivates the development of a more complete formulation of the calculation of this effect. While most effects on the CMB anisotropies are widely studied through direct solutions of the Boltzmann equation, the nonlinear effect of CMB lensing is formulated through the solutions of the geodesic equation. In this paper, we present a new formalism to the calculation of the lensing effect by directly solving the Boltzmann equation, as we did in the calculation of the CMB anisotropies at recombination. In particular, we developed a diagrammatic approach to efficiently keep track of all the interaction terms and calculate all possible nontrivial correlations to arbitrary high orders. Using this formalism, we explicitly articulate the approximations required to recover the usual remapping approach used in current studies of the weak lensing. In addition, we point out additional unexplored corrections that are manifest in our formalism to which experiments may be sensitive. As an example, we calculate the correction to the CMB temperature power spectrum for the lens-lens coupling effects which are neglected in standard calculations. We find that the correction is $\lesssim 0.1\%$ of the CMB temperature power spectrum for $\ell$ up to 3000 and thus is comparable to the cosmic variance.

We construct exact solutions describing the motion of rotating thin shells in a fully backreacted five-dimensional rotating black hole spacetime. The radial equation of motion follows from the Darmois-Israel junction conditions, where both interior and exterior geometries are taken to be equal angular momenta Myers-Perry solutions. We show that rotation generates anisotropic pressures and momentum along the shell. Gravitational collapse scenarios including rotation are analyzed and a new class of stationary solutions is introduced. Energy conditions for the anisotropic matter shell are briefly discussed. We find that the weak energy condition is not violated for the collapse scenario where the shell starts at rest from infinity, nor for the new class of stationary solutions in anti–de Sitter. We further prove that the cosmic censorship conjecture is always satisfied in our setup.

The analysis of charged-current quasielastic neutrino and antineutrino-nucleus scattering cross sections requires relativistic theoretical descriptions also accounting for the role of final-state interactions. We compare the results of the relativistic Green’s function model with the data recently published by the $\mathrm{MINER}\nu \mathrm{A}$ Collaboration. The model is able to describe both $\mathrm{MINER}\nu \mathrm{A}$ and MiniBooNE data.

We show that the local type non-Gaussianity in a class of curvaton models is suppressed, i.e., the nonlinearity parameters $f_{\text{NL}}$ and those related with higher order statistics can be at most $O(1)$, even if the curvaton energy density is subdominant at the decay. This situation is naturally realized in a very simple curvaton potential with quadratic term plus quartic term.

We compute the zero-recoil form factor for the semileptonic decay ${\overline{B}}^0\to D^{*+}{\ell }^{-}\overline{\nu }$ (and modes related by isospin and charge conjugation) using lattice QCD with three flavors of sea quarks. We use an improved staggered action for the light valence and sea quarks (the MILC asqtad configurations), and the Fermilab action for the heavy quarks. Our calculations incorporate higher statistics, finer lattice spacings, and lighter quark masses than our 2008 work. As a byproduct of tuning the new data set, we obtain the $D_s$ and $B_s$ hyperfine splittings with few-MeV accuracy. For the zero-recoil form factor, we obtain $\mathcal{F}(1)=0.906(4)(12)$, where the first error is statistical and the second is the sum in quadrature of all systematic errors. With the latest Heavy Flavor Averaging Group average of experimental results and a cautious treatment of QED effects, we find $|V_{cb}|=(39.04\pm 0.49_{\text{expt}}\pm 0.53_{\mathrm{QCD}}\pm 0.19_{\mathrm{QED}})\times 10^{-3}$. The QCD error is now commensurate with the experimental error.

We calculate the one-loop quantum corrections in the cubic Galileon theory, by using cutoff regularization. We confirm the expected form of the one-loop effective action and that the couplings of the Galileon theory do not get renormalized. However, new terms, not included in the tree-level action, are induced by quantum corrections. We also consider the one-loop corrections in an effective brane theory, which belongs to the Horndeski or generalized Galileon class. We find that new terms are generated by quantum corrections, while the tree-level couplings are also renormalized. We conclude that the structure of the generalized Galileon theories is altered by quantum corrections more radically than that of the Galileon theory.

Entanglement entropy in even-dimensional conformal field theories (CFTs) contains well-known universal terms arising from the conformal anomaly. Rényi entropies are natural generalizations of the entanglement entropy that are much less understood. Above two spacetime dimensions, the universal terms in the Rényi entropies are unknown for general entangling geometries. We conjecture a new structure in the dependence of the four-dimensional Rényi entropies on the intrinsic and extrinsic geometry of the entangling surface. We provide evidence for this conjecture by direct numerical computations in the free scalar and fermion field theories. The computation involves relating the four-dimensional free massless Rényi entropies across cylindrical entangling surfaces to corresponding three-dimensional massive Rényi entropies across circular entangling surfaces. Our numerical technique also allows us to directly probe other interesting aspects of three-dimensional Rényi entropy, including the massless renormalized Rényi entropy and calculable contributions to the perimeter law.

We consider a flat lattice of dipoles modeled by harmonic oscillators interacting with the electromagnetic field in the dipole approximation. Eliminating the variables from the coupled equations of motion, we come to effective Maxwell equations. These allow for taking the lattice spacing $a$ to zero. As a result, we obtain reflection coefficients for the scattering of electromagnetic waves off the sheet. These are a generalization of that known from the hydrodynamic model. For instance, we get a nontrivial scattering for polarizability perpendicular to the sheet. Also, we show that the case of polarizability parallel to the sheet can be obtained in a natural way from a plasma layer of finite thickness. As an alternative approach, we discuss the elimination of the electromagnetic fields resulting in effective equations for the oscillators. These are shown, for $a\to 0$, divergent behavior, resulting from the electrostatic interaction of the dipoles.