The postbounce oscillations of newly-born relativistic stars are expected to lead to gravitational-wave emission through the excitation of nonradial oscillation modes. At the same time, the star is oscillating in its radial modes, with a central density variation that can reach several percent. Nonlinear couplings between radial oscillations and polar nonradial modes lead to the appearance of combination frequencies (sums and differences of the linear mode frequencies). We study such combination frequencies using a gauge-invariant perturbative formalism, which includes bilinear coupling terms between different oscillation modes. For typical values of the energy stored in each mode we find that gravitational waves emitted at combination frequencies could become detectable in galactic core-collapse supernovae with advanced interferometric or wideband resonant detectors.

Next generation gravitational wave antennas employ resonant sideband extraction (RSE) interferometers with Fabry-Perot cavities in the arms as an optical configuration. In order to realize stable, robust control of the detector system, it is a key issue to extract appropriate control signals for longitudinal degrees of freedom of the complex coupled-cavity system. In this paper, a novel length sensing and control scheme is proposed for the tuned RSE interferometer that is both simple and efficient. The sensing matrix can be well diagonalized, owing to a simple allocation of two rf modulations and to a macroscopic displacement of the cavity mirrors, which cause a detuning of the rf modulation sidebands.

The minimal renormalizable supersymmetric SO(10) model, an SO(10) framework with only one $\mathbf{10}$ and one $\overline{\mathbf{126}}$ Higgs multiplets in the Yukawa sector, is attractive because of its high predictive power for the neutrino oscillation data. However, this model suffers from problems related to running of gauge couplings. The gauge coupling unification may be spoiled due to the presence of Higgs multiplets much lighter than the grand unification (GUT) scale. In addition, the gauge couplings blow up around the GUT scale because of the presence of Higgs multiplets of large representations. We consider the minimal SO(10) model in the warped extra dimension and find a possibility to solve these problems.

Dominant decay of a SM-like Higgs boson into particles beyond those contained in the minimal supersymmetric standard model has been identified as a natural scenario to avoid fine-tuning in electroweak symmetry breaking while satisfying all LEP limits. In the simplest of such an extension, the next-to-minimal supersymmetric model, the lightest $CP$-even Higgs boson can decay into two pseudoscalars. In the scenario with the least fine-tuning the lightest $CP$-even Higgs boson has a mass of order 100 GeV. In order to escape LEP limits it must decay to a pair of the lightest $CP$-odd Higgs bosons with $\mathrm{Br}(h\to aa)>.7$ and $m_a<2m_b$ (so that $a\to {\tau }^{+}{\tau }^{-}$ or light quarks and gluons). The mass of the lightest $CP$-odd Higgs boson is controlled by the soft-trilinear couplings, $A_{\lambda }(m_Z)$ and $A_{\kappa }(m_Z)$. We identify the region of parameter space where this situation occurs and discuss how natural this scenario is. It turns out that in order to achieve $m_a<2m_b$ with $A_{\lambda }(m_Z)$, $A_{\kappa }(m_Z)$ of order the typical radiative corrections, the required tuning of trilinear couplings needs not be larger than 5%–10%. Further, the necessity for this tuning can be eliminated in specific SUSY-breaking scenarios. Quite interestingly, $\mathrm{Br}(h\to aa)$ is typically above 70% in this region of parameter space and thus an appropriately large value requires no additional tuning.

We study the direct $CP$ violation in ${\overline{B}}^0\to {\rho }^0(\omega ){\rho }^0(\omega )\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$ [with unpolarized ${\rho }^0(\omega )$] via the $\rho -\omega$ mixing mechanism which causes a large strong phase difference and consequently a large $CP$ violating asymmetry when the masses of the ${\pi }^{+}{\pi }^{-}$ pairs are in the vicinity of the $\omega$ resonance. Since there are two $\rho (\omega )$ mesons in the intermediate state $\rho -\omega$ mixing contributes twice to the first order of isospin violation, leading to an even larger $CP$ violating asymmetry (it could be 30%–50% larger) than in the case where only one $\rho (\omega )$ meson is involved. The $CP$ violating asymmetry depends on the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the hadronic matrix elements. The factorization approach is applied in the calculation of the hadronic matrix elements with the nonfactorizable effects being included effectively in an effective parameter, $N_c$. We give the constraint on the range of $N_c$ from the latest experimental data for the branching ratios for ${\overline{B}}^0\to {\rho }^0{\rho }^0$ and ${\overline{B}}^0\to {\rho }^{+}{\rho }^{-}$. We find that the $CP$ violating asymmetry could be very large (even more than 90% for some values of $N_c$). It is shown that the sensitivity of the $CP$ violating asymmetry to $N_c$ is large compared with its smaller sensitivity to the CKM matrix elements. We also discuss the possibility to remove the mod ($\pi$) ambiguity in the determination of the $CP$ violating phase angle $\alpha$ through the measurement of the $CP$ violating asymmetry in the decay ${\overline{B}}^0\to {\rho }^0(\omega ){\rho }^0(\omega )\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\pi }^{-}$.

We have reanalyzed the world data on inclusive polarized deep inelastic scattering (DIS) including the very precise CLAS proton and deuteron data, as well as the latest COMPASS data on the asymmetry $A_1^d$, and have studied the impact of these data on polarized parton densities and higher twist effects. We demonstrate that the low $Q^2$ CLAS data improve essentially our knowledge of higher twist corrections to the spin structure function $g_1$, while the large $Q^2$ COMPASS data influence mainly the strange quark density. In our new analysis we find that a negative polarized gluon density, or one that changes sign as a function of $x$, cannot be ruled out on the basis of the present DIS data.

We present an analytic formula for differential cross section (DCS) of neutrino-electron scattering (NES) in a magnetic field (MF) with allowance for longitudinal polarizations of initial and final electrons (IAFE). The DCS of NES in a MF is sensitive to the spin variable of the IAFE and to the direction of the incident and scattered neutrinos (IASN) momenta. Spin asymmetries and field effects in NES in a MF enable us to use initial electrons having a left-hand circular polarization (LHCP) as polarized electron targets in detectors for detection of low-energy neutrinos or relic neutrinos and for distinguishing neutrino flavor (NF). In general, gas consisting of only electrons having a LHCP and gas consisting of only electrons having a right-hand circular polarization (RHCP) are heated by neutrinos asymmetrically. The asymmetry of heating (AH) is sensitive to NF, MF strength, energies (Landau quantum numbers and third components of the momenta) of IAFE, final electron chemical potential, the final temperature of gas consisting of only electrons having a LHCP (RHCP), polar angles of IASN momenta, the difference between the azimuthal angles of IASN momenta, the angle $\phi$, and IASN energies. In the heating process of electrons by neutrinos the dominant role belongs to electron neutrinos compared with the contribution of muon (tauon) neutrinos. Electrons having a LHCP in NES in a MF are heated by ${\nu }_e$ and ${\nu }_{\mu }({\nu }_{\tau })$ unequally when both the IASN fly along or against the MF direction. For magnetars and neutrinos of 1 MeV energy, within the considered kinematics, the AH in an electron neutrino-electron scattering is 2.23 times that in a muon neutrino-electron scattering or in a tauon neutrino-electron scattering.

An effective field theory model of the massive Yang-Mills theory is considered. Assuming that the renormalized coupling constants of ’nonrenormalizable’ interactions are suppressed by a large scale parameter it is shown that in analogy to the non-Abelian gauge invariant theory the dimensionless coupling constant vanishes logarithmically for large values of the renormalization scale parameter.

In a previous work we showed that large non-Gaussianities and nonscale-invariant distortions in the cosmic microwave background power spectrum can be generated in hybrid inflation models, due to the contributions of the tachyon (waterfall) field to the second order curvature perturbation. Here we clarify, correct, and extend those results. We show that large non-Gaussianity occurs only when the tachyon remains light throughout inflation, whereas $n=4$ contamination to the spectrum is the dominant effect when the tachyon is heavy. We find constraints on the parameters of warped-throat brane-antibrane inflation from non-Gaussianity. For F-term and D-term inflation models from supergravity, we obtain nontrivial constraints from the spectral distortion effect. We also establish that our analysis applies to complex tachyon fields.

In this paper, two important transport observables in the relativistic heavy ion collider (RHIC) experiment—damping rate and jet quenching parameter—are calculated from an AdS/QCD model. A quark moving in the viscous medium such as the quark-gluon-plasma is modeled by an open string whose end point travels on the boundary of a deformed ${\mathrm{AdS}}_5$ black hole. The correction introduced via the deformed ${\mathrm{AdS}}_5$ is believed to help us better understand the data which is expected to be measured in the RHIC.

We study multidimensional gravitational models with scalar curvature nonlinearity of the type $1/R$ and with form-fields (fluxes) as a matter source. It is assumed that the higher dimensional space-time undergoes Freund-Rubin-like spontaneous compactification to a warped product manifold. It is shown that for certain parameter regions the model allows for a freezing stabilization of the internal space near the positive minimum of the effective potential which plays the role of the positive cosmological constant. This cosmological constant provides the observable late-time accelerating expansion of the Universe if the parameters of the model are fine tuned. Additionally, the effective potential has the saddle point. It results in domain walls in the Universe. We show that these domain walls do not undergo inflation.

We demonstrate that in a vacuum-energy-dominated expansion phase, surprisingly neither the decay of matter nor matter-antimatter annihilation into relativistic particles can ever cause radiation to once again dominate over matter in the future history of the Universe.

We construct the complete set of positive parity pentaquarks, which correspond in the quark model to $\overline{s}{q}^{N_c+1}$ states with one unit of orbital angular momentum $L=1$. In the large $N_c$ limit they fall into the $\mathcal{K}=1/2$ and $\mathcal{K}=3/2$ irreps (towers) of the contracted $SU(4{)}_c$ symmetry. We derive predictions for the mass spectrum and the axial couplings of these states at leading order in $1/N_c$. The strong decay width of the lowest-lying positive parity exotic state is of order $O(1/N_c)$, such that this state is narrow in the large $N_c$ limit. Replacing the antiquark with a heavy antiquark $\overline{Q}{q}^{N_c+1}$, the two towers become degenerate, split only by $O(1/m_Q)$ hyperfine interactions. We obtain predictions for the strong decay widths of heavy pentaquarks to ordinary baryons and heavy $H_{\overline{Q}}^{(*)}$ mesons at leading order in $1/N_c$ and $1/m_Q$.

The finite-temperature behavior of gluon and Faddeev-Popov-ghost propagators is investigated for pure $SU(2)$ Yang-Mills theory in Landau gauge. We present nonperturbative results, obtained using lattice simulations and Dyson-Schwinger equations. Possible limitations of these two approaches, such as finite-volume effects and truncation artifacts, are extensively discussed. Both methods suggest a very different temperature dependence for the magnetic sector when compared to the electric one. In particular, a clear thermodynamic transition seems to affect only the electric sector. These results imply, in particular, the confinement of transverse gluons at all temperatures and they can be understood inside the framework of the so-called Gribov-Zwanziger scenario of confinement.

To understand the mass spectra of charged lepton and neutrino $A_4$ symmetry has been proposed in addition with the standard $SU(2{)}_L\times U(1{)}_Y$ model. We break $A_4$ symmetry softly and the deviation from the tribimaximal mixing arises due to Zee mechanism. In the present work, we express two mixing angles ${\theta }_{13}$ and ${\theta }_{23}$, in terms of a single model parameter and experimental observables, such as, mixing angle ${\theta }_{12}$, mass-squared differences $\Delta m_{21}^2$ and $\Delta m_{32}^2$. Using the experimental values of ${\theta }_{23}$, ${\theta }_{12}$, $\Delta m_{21}^2$, and $\Delta m_{32}^2$ we restrict the model parameter and we predict ${\theta }_{13}$. This model gives rise to ${\theta }_{13}\simeq 11°$ if we allow $1\sigma$ deviation of ${\theta }_{23}$ and 2° deviation of ${\theta }_{12}$ from their best fit values. Utilizing all those constraints, we explore the extent of $CP$ violation parameter $J_{CP}$ in the present model and found a value of $J_{CP}\approx 2.65\times {10}^{-3}$ (for $1\sigma$ deviation of ${\theta }_{23}$ and 2° deviation of ${\theta }_{12}$) consistent with the other neutrino experimental results. We have studied the mass pattern of neutrino and neutrinoless double beta decay $(\beta {\beta }_{0\nu })$ parameter $|(M_{\nu }{)}_{ee}|$ in this model.

The weak radiative corrections to the Drell-Yan process above the $Z$-peak have been studied. The compact asymptotic expression for the two heavy boson exchange—one of the significant contributions to the investigated process—has been obtained, the results expand in the powers of the Sudakov electroweak logarithms. At the quark level we compare the weak radiative corrections to the total cross section and forward-backward asymmetry with the existing results and achieve a rather good coincidence at $\sqrt{s}\gtrsim 0.5\mathrm{TeV}$. The numerical analysis has been performed in the high energy region corresponding to the future experiments at the CERN Large Hadron Collider (LHC). To simulate the detector acceptance we used the standard CMS detector cuts. It was shown that double Sudakov logarithms of the WW boxes are the dominant contributions in hadronic cross section. The considered radiative corrections are significant at high dilepton mass $M$ and change the dilepton mass distribution up to $\sim +3(-12)\%$ at the LHC energies and $M=1(5)\mathrm{TeV}$.

The scale of fermion mass generation can, as shown by Appelquist and Chanowitz, be bounded from above by relating it to the scale of unitarity violation in the helicity nonconserving amplitude for fermion-anti-fermion pairs to scatter into pairs of longitudinally polarized electroweak gauge bosons. In this paper, we examine the process $t\overline{t}\to W_L^{+}{W}_L^{-}$ in a family of phenomenologically-viable deconstructed Higgsless models and we show that scale of unitarity violation depends on the mass of the additional vectorlike fermion states that occur in these theories (the states that are the deconstructed analogs of Kaluza-Klein partners of the ordinary fermions in a five-dimensional theory). For sufficiently light vector fermions, and for a deconstructed theory with sufficiently many lattice sites (that is, sufficiently close to the continuum limit), the Appelquist-Chanowitz bound can be substantially weakened. More precisely, we find that, as one varies the mass of the vectorlike fermion for fixed top-quark and gauge-boson masses, the bound on the scale of top-quark mass generation interpolates smoothly between the Appelquist-Chanowitz bound and one that can, potentially, be much higher. In these theories, therefore, the bound on the scale of fermion mass generation is independent of the bound on the scale of gauge-boson mass generation. While our analysis focuses on deconstructed Higgsless models, any theory in which top-quark mass generation proceeds via the mixing of chiral and vector fermions will give similar results.

The flat directions $LLe$ and $udd$ within the minimal supersymmetric standard model provide all the necessary ingredients for a successful inflation with the right amplitude of the scalar density perturbations, negligible gravity waves and the spectral tilt within $2\sigma$ observed range $0.92\le n_s\le 1.0$. In this paper we explore the available parameter space for inflation in conjunction with a thermal cold dark matter abundance within the minimal supergravity model. Remarkably for the inflaton, which is a combination of squarks and sleptons, there is a stau-neutralino coannihilation region below the inflaton mass 500 GeV for the observed density perturbations and the tilt of the spectrum. For such a low mass of the inflaton the LHC is capable of discovering the inflaton candidates within a short period of its operation. Inflation is also compatible with the focus point region which opens up for the inflaton masses above TeV. We show that embedding MSSM within $SO(10)$ can naturally favor this region.

It is shown explicitly that in classical dynamics of theories with higher derivatives there arises the exponential instability with respect to external dissipative force. For this aim, the equations of motion for the Pais-Uhlenbeck fourth order oscillator with damping are investigated and the corrections to the oscillator frequencies due to the friction force are calculated.