We derive and analyze Noether charges associated with the diffeomorphism invariance for the constrained $SO(2,3)$ BF theory. This result generalizes the Wald approach to the case of the first order gravity with a negative cosmological constant, the Holst modification, and topological terms (Nieh-Yan, Euler, and Pontryagin). We show that differentiability of the action is automatically implemented by the structure of the constrained BF model. Finally, we calculate the AdS–Schwarzschild black hole entropy from the Noether charge and we find that it does not depend on the Immirzi parameter.

A novel hierarchical search technique is presented for all-sky surveys for continuous gravitational-wave sources, such as rapidly spinning nonaxisymmetric neutron stars. Analyzing yearlong detector data sets over realistic ranges of parameter space using fully coherent matched-filtering is computationally prohibitive. Thus more efficient, so-called hierarchical techniques are essential. Traditionally, the standard hierarchical approach consists of dividing the data into nonoverlapping segments of which each is coherently analyzed, and subsequently the matched-filter outputs from all segments are combined incoherently. The present work proposes to break the data into subsegments shorter than the desired maximum coherence time span (size of the coherence window). Then matched-filter outputs from the different subsegments are efficiently combined by sliding the coherence window in time: Subsegments whose timestamps are closer than coherence window size are combined coherently, otherwise incoherently. Compared to the standard scheme at the same coherence time baseline, data sets longer by about 50–100% would have to be analyzed to achieve the same search sensitivity as with the sliding coherence window approach. Numerical simulations attest to the analytically estimated improvement.

We investigate flavor violating decays of the long-lived lightest slepton and the tau lepton in the coannihilation region of the minimal supersymmetric standard model with a seesaw mechanism to generate neutrino masses. We consider a situation where the mass difference between the lightest neutralino, as the lightest supersymmetric particle , and the lightest slepton, as the next-to-lightest supersymmetric particle, is smaller than the mass of tau lepton. In this situation, the lifetime of the lightest slepton is very long and it is determined by lepton flavor violating (LFV) couplings because the slepton mainly consists of the lighter stau and the flavor conserving 2-body decay is kinematically forbidden. We show that the lifetime can change many orders of magnitude by varying the Yukawa couplings entering the seesaw mechanism. We also show that the branching ratios of LFV tau decays are strongly correlated with the lightest slepton lifetime. Therefore the branching ratios of LFV tau decays can be determined or constrained by measuring the slepton lifetime at the LHC experiment.

We discuss the feasibility of seeing a Higgs boson that decays to four partons through a pair of (pseudo)scalars at the LHC. We restrict our search to Higgs bosons produced in association with a $W/Z$ boson at high transverse momentum. We argue that subjet analysis techniques are a good discriminant between such events and $W/Z+\mathrm{\text{jets}}$ and $t\overline{t}$ production. For light scalar masses (below 30 GeV), we find evidence that a flavor-independent search for such a nonstandard Higgs boson is plausible with $100{\mathrm{fb}}^{-1}$ of data, while a Higgs decaying to heavier scalars is only likely to be visible in models where scalar decays to $b$ quarks dominate.

A new method of stochastically estimating the low-lying effects of quark propagation is proposed which allows accurate determinations of temporal correlations of single-hadron and multihadron operators in lattice QCD. The method is well suited for calculations in large volumes. Contributions involving quark propagation connecting hadron sink operators at the same final time can be handled in a straightforward manner, even for a large number of final time slices. The method exploits Laplacian Heaviside (LapH) smearing. $Z_N$ noise is introduced in a novel way, and variance reduction is achieved using judiciously-chosen noise-dilution projectors. The method is tested using isoscalar mesons in the scalar, pseudoscalar, and vector channels, and using the two-pion system of total isospin $I=0$, 1, 2 on large anisotropic ${24}^3\times 128$ lattices with spatial spacing $a_s\sim 0.12\mathrm{fm}$ and temporal spacing $a_t\sim 0.034\mathrm{fm}$ for pion masses $m_{\pi }\approx 390$ and 240 MeV.

We argue that the $t\overline{t}$ production asymmetry observed at the Tevatron might be simply explained if the standard $SU(3{)}_c$ QCD theory is extended to $SU(N_c)$ which is spontaneously broken at a scale just above the weak scale. The extended gauge interactions amplify the radiative QCD contribution to the asymmetry and can potentially explain the observations if $N_c\gtrsim 5$. This explanation suggests a relatively low $SU(N_c)$ symmetry breaking scale $\lesssim 0.5–1\mathrm{TeV}$. We check that such a low $SU(N_c)$ symmetry breaking scale is consistent with current collider data. Importantly this scenario predicts an abundance of striking phenomena which will be probed at the LHC. The $SU(N_c)$ model also illustrates the idea that a beyond standard model contribution to the $t\overline{t}$ asymmetry might arise primarily via radiative corrections rather than at tree level.

A two-dimensional Fourier transform of hadron form factors allows to determine their charge density in transverse space. We show that this method can be applied to any virtual photon induced transition, such as ${\gamma }^{*}(q)+N\to \pi N$. Only Fock states that are common to the initial and final states contribute to the amplitudes, which are determined by the overlap of the corresponding light-front wave functions. Their transverse extent may be studied as a function of the final state configuration, allowing qualitatively new insight into strong interaction dynamics. Fourier transforming the cross section (rather than the amplitude) gives the distribution of the transverse distance between the virtual photon interaction vertices in the scattering amplitude and its complex conjugate. While the measurement of parton distributions in longitudinal momentum depends on the leading twist approximation ($-q^2\to \infty$ limit), all $q^2<0$ values contribute to the Fourier transform, with the transverse resolution increasing with the available range in $q^2$. We illustrate the method using QED amplitudes.

There is a direct group-theoretical connection between neutrino mixing and horizontal symmetry that can be established without any dynamical input. Such a connection is reviewed and expanded in this article. For certain symmetry groups $\mathcal{G}$ including $A_4$ and $S_4$, it is shown that a generic $U(1)\times \mathcal{G}$ Higgs potential of a valon yields exactly the alignments dictated by the group-theoretical approach, but energy can now be used to discriminate different alignments. This mechanism possibly explains why starting from an $A_4$ group, the tribimaximal mixing matrix with an enhanced $S_4$ symmetry is more preferable than the one without it.

We present a measurement of the top quark mass in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ and dilepton channels of $t\overline{t}$ decays using the data sample corresponding to an integrated luminosity of $5.6{\mathrm{fb}}^{-1}$ of $p\overline{p}$ collisions at Tevatron with $\sqrt{s}=1.96\mathrm{TeV}$, collected with the CDF II detector. We construct templates of two reconstructed top quark masses from different jets-to-quarks combinations and the invariant mass of two jets from the $W$ decays in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ channel, and a reconstructed top quark mass and $m_{T2}$, a variable related to the transverse mass in events with two missing particles, in the dilepton channel. The simultaneous fit of the templates from signal and background events in the $\mathrm{\text{lepton}}+\mathrm{\text{jets}}$ and dilepton channels to the data yields a measured top quark mass of ${\mathrm{M}}_{\mathrm{top}}=172.1\pm 1.1(\mathrm{stat})\pm 0.9(\mathrm{syst})\mathrm{GeV}/c^2$.

We introduce new sum rules allowing to determine universal properties of the unknown component of the cosmic rays; we show how they can be used to predict the positron fraction at energies not yet explored by current experiments, and to constrain specific models.

When the spontaneous symmetry breaking occurs for systems without Lorentz covariance, there arises possible mismatch, $N_{\mathrm{NG}}<N_{\mathrm{BG}}$, between numbers of Nambu-Goldstone (NG) bosons ($N_{\mathrm{NG}}$) and the numbers of broken generators ($N_{\mathrm{BG}}$). In such a situation, so-called type-II NG bosons emerge. We study how the gauge bosons acquire masses through the Higgs mechanism under this mismatch by employing gauge theories with complex scalar field at finite chemical potential and by enforcing “charge” neutrality. To separate the physical spectra from unphysical ones, the $R_{\xi }$ gauge is adopted. Not only massless NG bosons but also massive scalar bosons generated by the chemical potential are absorbed into spatial components of the gauge bosons. Although the chemical potential induces a nontrivial mixings among the scalar bosons and temporal components of the gauge bosons, it does not affect the structure of the physical spectra, so that the total number of physical modes is not modified even for $N_{\mathrm{NG}}<N_{\mathrm{BG}}$.

We deduce a new formula for the perihelion advance $\Theta$ of a test particle in the Schwarzschild black hole by applying a newly developed nonlinear transformation within the Schwarzschild space-time. By this transformation we are able to apply the well-known formula valid in the weak-field approximation near infinity also to trajectories in the strong-field regime near the horizon of the black hole. The resulting formula has the structure $\Theta =c_1-c_2\ln (c_3^2-e^2)$ with positive constants $c_{1,2,3}$ depending on the angular momentum of the test particle. It is especially useful for orbits with large eccentricities $e<c_3<1$ showing that $\Theta \to \infty$ as $e\to c_3$.

We investigate the stability of an $f(R)$ (Schwarzschild) black hole obtained from the $f(R)$ gravity. It is difficult to carry out the perturbation analysis around the black hole because the linearized Einstein equation is fourth order in $f(R)$ gravity. In order to resolve this difficulty, we transform $f(R)$ gravity into the scalar-tensor theory by introducing two auxiliary scalars. In this case, the linearized curvature scalar becomes a scalaron, showing that all linearized equations are second order, which are the same equations for the massive Brans-Dicke theory. It turns out that the $f(R)$ black hole is stable against the external perturbations if the scalaron does not have a tachyonic mass.

Indications of spatial variation of the fine-structure constant, $\alpha$, based on study of quasar absorption systems have recently been reported [J. K. Webb, J. A. King, M. T. Murphy, V. V. Flambaum, R. F. Carswell, and M. B. Bainbridge, arXiv:1008.3907.]. The physics that causes this $\alpha$-variation should have other observable manifestations, and this motivates us to look for complementary astrophysical effects. In this paper we propose a method to test whether spatial variation of fundamental constants existed during the epoch of big bang nucleosynthesis and study existing measurements of deuterium abundance for a signal. We also examine existing quasar absorption spectra data that are sensitive to variation of the electron-to-proton mass ratio $\mu$ and $x={\alpha }^2\mu g_p$ for spatial variation.

On large scales, comparable to the horizon, the observable clustering properties of galaxies are affected by various general relativistic effects. To calculate these effects one needs to consistently solve for the metric, densities, and velocities in a specific coordinate system or gauge. The method of choice for simulating large-scale structure is numerical N-body simulations which are performed in the Newtonian limit. Even though one might worry that the use of the Newtonian approximation would make it impossible to use these simulations to compute properties on very large scales, we show that the simulations are still solving the dynamics correctly even for long modes and we give formulas to obtain the position of particles in the conformal Newtonian gauge given the positions computed in the simulation. We also give formulas to convert from the output coordinates of N-body simulations to the observable coordinates of the particles.

Recent cosmological data analyses hint at the presence of an extra relativistic energy component in the early universe. This component is often parametrized as an excess of the effective neutrino number $N_{\mathrm{eff}}$ over the standard value of 3.046. The excess relativistic energy could be an indication for an extra (sterile) neutrino, but early dark energy and barotropic dark energy also contribute to the relativistic degrees of freedom. We examine the capabilities of current and future data to constrain and discriminate between these explanations, and to detect the early dark energy density associated with them. We find that while early dark energy does not alter the current constraints on $N_{\mathrm{eff}}$, a dark radiation component, such as that provided by barotropic dark energy models, can substantially change current constraints on $N_{\mathrm{eff}}$, bringing its value back to agreement with the theoretical prediction. Both dark energy models also have implications for the primordial mass fraction of Helium $Y_p$ and the scalar perturbation index $n_s$. The ongoing Planck satellite mission will be able to further discriminate between sterile neutrinos and early dark energy.

We present the calculation of the atmospheric neutrino fluxes with an interaction model named JAM, which is used in PHITS (Particle and Heavy-Ion Transport code System) [K. Niita et al., Radiation Measurements 41, 1080 (2006).]. The JAM interaction model agrees with the HARP experiment [H. Collaboration, Astropart. Phys. 30, 124 (2008).] a little better than DPMJET-III [S. Roesler, R. Engel, and J. Ranft, arXiv:hep-ph/0012252.]. After some modifications, it reproduces the muon flux below $1\mathrm{GeV}/c$ at balloon altitudes better than the modified DPMJET-III, which we used for the calculation of atmospheric neutrino flux in previous works [T. Sanuki, M. Honda, T. Kajita, K. Kasahara, and S. Midorikawa, Phys. Rev. D 75, 043005 (2007).][M. Honda, T. Kajita, K. Kasahara, S. Midorikawa, and T. Sanuki, Phys. Rev. D 75, 043006 (2007).]. Some improvements in the calculation of atmospheric neutrino flux are also reported.

A warped extra-dimensional model, where the standard model Yukawa hierarchy is set by UV physics, is shown to have a sweet spot of parameters with improved experimental visibility and possibly naturalness. Upon marginalizing over all the model parameters, a Kaluza-Klein scale of 2.1 TeV can be obtained at $2\sigma$ (95.4% C.L.) without conflicting with electroweak precision measurements. Fitting all relevant parameters simultaneously can relax this bound to 1.7 TeV. In this bulk version of the Rattazzi-Zaffaroni shining model, flavor violation is also highly suppressed, yielding a bound of 2.4 TeV. Nontrivial flavor physics at the LHC in the form of flavor gauge bosons is predicted. The model is also characterized by a depletion of the third-generation couplings—as predicted by the general minimal flavor violation framework—which can be tested via flavor precision measurements. In particular, sizable $CP$ violation in $\Delta B=2$ transitions can be obtained, and there is a natural region where $B_s$ mixing is predicted to be larger than $B_d$ mixing, as favored by recent Tevatron data. Unlike other proposals, the new contributions are not linked to Higgs or any scalar exchange processes.

We present a connection between two known solutions to the strong-$CP$ problem: the standard introduction of axions and the extra-dimensional one, relying on topological arguments. Using an equivalent lower-dimensional setup with a warped extra dimension but without adding any new fields, it is shown that an additional light degree of freedom appears. Like an axion, it couples to the topological charge density via fermionic loop corrections. Its decay constant is related to the geometry of the extra dimension and is suppressed by the warping scale.