The averaged null energy condition (ANEC) states that the integral along a complete null geodesic of the projection of the stress-energy tensor onto the tangent vector to the geodesic cannot be negative. Exotic spacetimes, such as those allow wormholes or the construction of time machines are possible in general relativity only if ANEC is violated along achronal geodesics. Starting from a conjecture that flat-space quantum inequalities apply with small corrections in spacetimes with small curvature, we prove that ANEC is obeyed by a minimally coupled, free quantum scalar field on any achronal null geodesic surrounded by a tubular neighborhood whose curvature is produced by a classical source.

We calculate the odd-parity, radiative ($\ell \ge 2$) parts of the metric perturbation in Lorenz gauge caused by a small compact object in eccentric orbit about a Schwarzschild black hole. The Lorenz gauge solution is found via gauge transformation from a corresponding one in Regge-Wheeler gauge. Like the Regge-Wheeler gauge solution itself, the gauge generator is computed in the frequency domain and transferred to the time domain. The wave equation for the gauge generator has a source with a compact, moving delta-function term and a discontinuous noncompact term. The former term allows the method of extended homogeneous solutions to be applied (which circumvents the Gibbs phenomenon). The latter has required the development of new means to use frequency domain methods and yet be able to transfer to the time domain while avoiding Gibbs problems. Two new methods are developed to achieve this: a partial annihilator method and a method of extended particular solutions. We detail these methods and show their application in calculating the odd-parity gauge generator and Lorenz gauge metric perturbations. A subsequent paper will apply these methods to the harder task of computing the even-parity parts of the gauge generator.

We consider a search for phenomenological signatures from an hypothetical spacetime granularity that respects Lorentz invariance. The model is based on the idea that the metric description of Einstein’s gravity corresponds to a hydrodynamic characterization of some deeper underlying structure, and that Einstein’s gravity is thus to be seen as emergent. We present the specific phenomenological model in detail and analyze the bounds on its free parameters established by an experiment specifically designed to test this model.

We show that there are two equivalent first order descriptions of $2+1$ gravity with a nonzero cosmological constant. One is the well-known spacetime description, and the other is in terms of evolving conformal geometry. The key tool that links these pictures is Cartan geometry, a generalization of Riemannian geometry that allows for geometries locally modeled off arbitrary homogeneous spaces. The two different interpretations suggest two distinct phase space reductions. The spacetime picture leads to the $2+1$ formulation of general relativity due to Arnowitt, Deser, and Misner, while the conformal picture leads to shape dynamics. Cartan geometry thus provides an alternative to symmetry trading for explaining the equivalence of general relativity and shape dynamics.

We derive a redshift drift formula for the spherically symmetric inhomogeneous pressure Stephani universes which are complementary to the spherically symmetric inhomogeneous density Lemaître-Tolman-Bondi models. We show that there is a clear difference between redshift drift predictions for these two models as well as between the Stephani models and the standard $\Lambda \mathrm{CDM}$ Friedmann models. The Stephani models have positive drift values at small redshift and behave qualitatively (but not quantitatively) as the $\Lambda \mathrm{CDM}$ models at large redshift, while the drift for Lemaître-Tolman-Bondi models is always negative. This prediction may perhaps be tested in future telescopes such as European Extremely Large Telescope (with its spectrograph Cosmic Dynamics Explorer), the Thirty Meter Telescope, the Giant Magellan Telescope, and especially, in gravitational wave interferometers Deci-Hertz Interferometer Gravitational Wave Observatory and Big Bang Observatory [K. Yagi and N. Seto, Phys. Rev. D 83, 044011 (2011).].

An improved estimator for the amplitude $f_{\mathrm{NL}}$ of local-type non-Gaussianity from the cosmic microwave background (CMB) bispectrum is discussed. The standard estimator is constructed to be optimal in the zero-signal (i.e., Gaussian) limit. When applied to CMB maps which have a detectable level of non-Gaussianity the standard estimator is no longer optimal, possibly limiting the sensitivity of future observations to a non-Gaussian signal. Previous studies have proposed an improved estimator by using a realization-dependent normalization. Under the approximations of a flat sky and a vanishingly thin last-scattering surface, these studies showed that the variance of this improved estimator can be significantly smaller than the variance of the standard estimator when applied to non-Gaussian CMB maps. Here this technique is generalized to the full sky and to include the full radiation transfer function, yielding expressions for the improved estimator that can be directly applied to CMB maps. The ability of this estimator to reduce the variance as compared to the standard estimator in the face of a significant non-Gaussian signal is re-assessed using the full CMB transfer function. As a result of the late time integrated Sachs-Wolfe (ISW) effect, the performance of the improved estimator is degraded. If CMB maps are first cleaned of the late-time ISW effect using a tracer of foreground structure, such as a galaxy survey or a measurement of CMB weak lensing, the new estimator does remove a majority of the excess variance, allowing a higher significance detection of $f_{\mathrm{NL}}$.

This paper is divided into two parts. In the first part we analyze the consequences, for the LHC, of gauge and third-family Yukawa coupling unification with a particular set of boundary conditions defined at the grand unification scale. We perform a global ${\chi }^2$ analysis including the observables $M_W$, $M_Z$, $G_F$, ${\alpha }_{\mathrm{em}}^{-1}$, ${\alpha }_s(M_Z)$, $M_t$, $m_b(m_b)$, $M_{\tau }$, $\mathrm{BR}(B\to X_s\gamma )$, $\mathrm{BR}(B_s\to {\mu }^{+}{\mu }^{-})$, and $M_h$. The fit is performed in the minimal supersymmetric Standard Model in terms of nine grand unification-scale parameters, while $\tan \beta$ and $\mu$ are fixed at the weak scale. Good fits suggest an upper bound on the gluino mass, $M_{\tilde{g}}\lesssim 2\mathrm{TeV}$. This constraint comes predominantly from fitting the bottom-quark and Higgs masses (assuming a 125 GeV Higgs). Gluinos should be visible at the LHC in the 14 TeV run but they cannot be described by the typical simplified models. This is because the branching ratios for $\tilde{g}\to t\overline{t}{\tilde{\chi }}_{1,2}^0$, $b\overline{b}{\tilde{\chi }}_{1,2}^0$, $t\overline{b}{\tilde{\chi }}_{1,2}^{-}$, $b\overline{t}{\tilde{\chi }}_{1,2}^{+}$, $g{\tilde{\chi }}_{1,2,3,4}^0$ are comparable. Top squarks and sbottoms may also be visible. Charginos and neutralinos can be light, with the lightest supersymmetric particle predominantly bino-like. In the second part of the paper we analyze a complete three-family model and discuss the quality of the global ${\chi }^2$ fits and the differences between the third-family analysis and the full three-family analysis for overlapping observables. We note that the light Higgs in our model couples to matter like the Standard Model Higgs. Any deviation from this would rule out this model.

We present a systematic study of the effectiveness of light quark mass reweighting. This method allows a single, lattice QCD ensemble, generated with a specific value of the dynamical light quark mass, to be used to determine results for other, nearby light dynamical quark masses. We study two gauge field ensembles generated with $2+1$ flavors of dynamical domain wall fermions with light quark masses $m_l=0.02$ ($m_{\pi }=620\mathrm{MeV}$) and $m_l=0.01$ ($m_{\pi }=420\mathrm{MeV}$). We reweight each ensemble to determine results that could be computed directly from the other and check the consistency of the reweighted results with the direct results. The large difference between the 0.02 and 0.01 light quark masses suggests that this is an aggressive application of reweighting as can be seen from fluctuations in the magnitude of the reweighting factor by 4 orders of magnitude. Nevertheless, a comparison of the reweighed topological charge, average plaquette, residual mass, pion mass, pion decay constant, and scalar correlator between these two ensembles shows an agreement well described by the statistical errors. The issues of the effective number of configurations and finite sample bias are discussed. An examination of the topological charge distribution implies that it is more favorable to reweight from heavier mass to lighter quark mass.

We study the coupled $\pi N$ system (negative parity, isospin $\frac{1}{2}$) based on a lattice QCD simulation for $n_f=2$ mass degenerate light quarks. Both standard 3-quark baryon operators as well as meson-baryon ($4+1$)-quark operators are included. This is an exploratory study for just one lattice size and lattice spacing and at a pion mass of 266 MeV. Using the distillation method and variational analysis we determine energy levels of the lowest eigenstates. Comparison with the results of simple 3-quark correlation studies exhibits drastic differences and a new level appears. A clearer picture of the negative parity nucleon spectrum emerges. For the parameters of the simulation we may assume elastic $s$-wave scattering and can derive values of the phase shift.

We present the thermodynamic properties of strongly interacting matter in finite volume in the framework of Polyakov loop enhanced Nambu-Jona-Lasinio model within mean field approximation. We considered both the 2 flavor and $2+1$ flavor matter. Our primary observation was a qualitative change in the phase transition properties that resulted in the lowering of the temperature corresponding to the critical endpoint. This would make it favorable for detection in heavy-ion experiments that intend to create high density matter with considerably small temperatures. We further demonstrate the possibility of obtaining chiral symmetry restoration even within the confined phase in finite volumes.

In a previous article [A. Faessler et al., Phys. Rev. D 79, 053001 (2009)], we estimated the correlated uncertainties associated to the nuclear matrix elements of neutrinoless double beta decay ($0\nu \beta \beta$) within the quasiparticle random phase approximation. Such estimates encompass recent independent calculations of nuclear matrix elements and can thus still provide a fair representation of the nuclear model uncertainties. In this context, we compare the claim of $0\nu \beta \beta$ decay in ${}^{76}\mathrm{Ge}$ with recent negative results in ${}^{136}\mathrm{Xe}$ and in other nuclei, and we infer the lifetime ranges allowed or excluded at 90% C.L. We also highlight some issues that should be addressed in order to properly compare and combine results coming from different $0\nu \beta \beta$ candidate nuclei.

The measurements of the Higgs boson and top-quark masses can be used to extrapolate the Standard Model Higgs potential at energies up to the Planck scale. Adopting a next-to-next-to-leading-order renormalization procedure, we (i) find that electroweak vacuum stability is at present allowed and discuss the associated theoretical and experimental errors and the prospects for its future tests, (ii) determine the boundary conditions allowing for the existence of a shallow false minimum slightly below the Planck scale, which is a stable configuration that might have been relevant for primordial inflation, and (iii) derive a conservative upper bound on type-I seesaw right-handed neutrino masses, following from the requirement of electroweak vacuum stability.

We present a search for charged massive long-lived particles (CMLLPs) that are pair produced in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$ collected by the D0 experiment at the Fermilab Tevatron collider. Our result is a combination of two searches where either one or both CMLLPs are reconstructed in the detector. We select events with muonlike particles that have both speed and ionization energy loss ($\mathrm{d}E/\mathrm{d}x$) different from muons produced in $p\overline{p}$ collisions. In the absence of evidence for CMLLPs corresponding to $6.3{\mathrm{fb}}^{-1}$ of integrated luminosity, we set limits on the CMLLP masses in several supersymmetric models, excluding masses below 278 GeV for long-lived gaugino-like charginos, and masses below 244 GeV for long-lived Higgsino-like charginos at the 95% C.L. We also set limits on the cross section for pair production of long-lived scalar tau leptons that range from 0.04 to 0.008 pb for scalar tau lepton masses of 100–300 GeV.

We report on a search for direct $CP$ violation in the singly Cabibbo-suppressed decay $D^{+}\to K^{+}{K}^{-}{\pi }^{+}$ using a data sample of $476{\mathrm{fb}}^{-1}$ of $e^{+}{e}^{-}$ annihilation data accumulated with the BABAR detector at the SLAC PEP-II electron-positron collider, running at and just below the energy of the ${\rm Y}(4S)$ resonance. The integrated $CP$-violating decay rate asymmetry $A_{CP}$ is determined to be $(0.37\pm 0.30\pm 0.15)\%$. Model-independent and model-dependent Dalitz plot analysis techniques are used to search for $CP$-violating asymmetries in the various intermediate states. We find no evidence for $CP$-violation asymmetry.

We present improved measurements of $CP$-violation parameters in the decays $B^0\to {\pi }^{+}{\pi }^{-}$, $B^0\to K^{+}{\pi }^{-}$, and $B^0\to {\pi }^0{\pi }^0$, and of the branching fractions for $B^0\to {\pi }^0{\pi }^0$ and $B^0\to K^0{\pi }^0$. The results are obtained with the full data set collected at the ${\rm Y}(4S)$ resonance by the BABAR experiment at the PEP-II asymmetric-energy $B$ factory at the SLAC National Accelerator Laboratory, corresponding to $(467\pm 5)\times {10}^6$ $B\overline{B}$ pairs. We find the $CP$-violation parameter values and branching fractions: $S_{{\pi }^{+}{\pi }^{-}}=-0.68\pm 0.10\pm 0.03$, $C_{{\pi }^{+}{\pi }^{-}}=-0.25\pm 0.08\pm 0.02$, ${\mathcal{A}}_{K^{-}{\pi }^{+}}=-0.107\pm {0.016}_{-0.004}^{+0.006}$, $C_{{\pi }^0{\pi }^0}=-0.43\pm 0.26\pm 0.05$, $\mathcal{B}(B^0\to {\pi }^0{\pi }^0)=(1.83\pm 0.21\pm 0.13)\times {10}^{-6}$, $\mathcal{B}(B^0\to K^0{\pi }^0)=(10.1\pm 0.6\pm 0.4)\times {10}^{-6}$, where in each case, the first uncertainties are statistical and the second are systematic. We observe $CP$ violation with a significance of 6.7 standard deviations for $B^0\to {\pi }^{+}{\pi }^{-}$ and 6.1 standard deviations for $B^0\to K^{+}{\pi }^{-}$, including systematic uncertainties. Constraints on the unitarity triangle angle $\alpha$ are determined from the isospin relations among the $B\to \pi \pi$ rates and asymmetries. Considering only the solution preferred by the Standard Model, we find $\alpha$ to be in the range [71°,109°] at the 68% confidence level.

We present an updated search for the Higgs boson produced in association with a vector boson in the final state with missing transverse energy and two jets. We use the full CDF data set corresponding to an integrated luminosity of $9.45{\mathrm{fb}}^{-1}$ at a proton-antiproton center-of-mass energy of $\sqrt{s}=1.96\mathrm{TeV}$. New to this analysis is the inclusion of a $b$-jet identification algorithm specifically optimized for $H\to b\overline{b}$ searches. Across the Higgs boson mass range $90\le m_H\le 150\mathrm{GeV}/c^2$, the expected 95% credibility level upper limits on the $VH$ production cross section times the $H\to b\overline{b}$ branching fraction are improved by an average of 14% relative to the previous analysis. At a Higgs boson mass of $125\mathrm{GeV}/c^2$, the observed (expected) limit is 3.06 (3.33) times the standard model prediction, corresponding to one of the most sensitive searches to date in this final state.

We study the analytic structure of the two-point function of the operator $F^2$ which is expected to describe a scalar glueball. The calculation of the involved integrals is complicated by nonanalytic structures in the integrands, which we take into account properly by identifying cuts generated by angular integrals and deforming the contours for the radial integration accordingly. The obtained locations of the branch points agree with Cutkosky’s cut rules. As input we use different nonperturbative Landau gauge gluon propagators with different analytic properties as obtained from lattice and functional calculations. All of them violate positivity and describe thus gluons absent from the asymptotic physical space. The resulting spectral densities for the glueball candidate show a cut but no poles for lightlike momenta, which can be attributed to the employed Born approximation.

Common extensions of the Standard Model of particle physics predict the existence of a “hidden” sector that comprises particles with a vanishing or very weak coupling to particles of the Standard Model (visible sector). For very light ($m<{10}^{-14}\mathrm{eV}$) hidden U(1) gauge bosons (hidden photons), broadband radio spectra of compact radio sources could be modified due to weak kinetic mixing with radio photons. Here, search methods are developed and their sensitivity discussed, with specific emphasis on the effect of the coherence length of the signal, instrumental bandwidth, and spectral resolution. We conclude that radio observations in the frequency range of 0.03–1400 GHz probe kinetic mixing of $\sim {10}^{-3}$ of hidden photons with masses down to $\sim {10}^{-17}\mathrm{eV}$. Prospects for improving the sensitivity with future radio astronomical facilities as well as by stacking data from multiple objects are discussed.