Compact binary systems with total masses between tens and hundreds of solar masses will produce gravitational waves during their merger phase that are detectable by second-generation ground-based gravitational-wave detectors. In order to model the gravitational waveform of the merger epoch of compact binary coalescence, the full Einstein equations must be solved numerically for the entire mass and spin parameter space. However, this is computationally expensive. Several models have been proposed to interpolate the results of numerical relativity simulations. In this paper we propose a numerical interpolation scheme that stems from the singular value decomposition. This algorithm shows promise in allowing one to construct arbitrary waveforms within a certain parameter space given a sufficient density of numerical simulations covering the same parameter space. We also investigate how similar approaches could be used to interpolate waveforms in the context of parameter estimation.

The explanation of the large $CP$ asymmetries in $D^0\to ({\pi }^{+}{\pi }^{-},K^{+}{K}^{-})$ decays observed by the LHCb collaboration is likely to call for new physics beyond the Cabibbo-Kobayashi-Maskawa quark-mixing matrix (CKM) paradigm. We explore new contributions caused by the color sextet scalar diquark, and demonstrate that the diquark with the mass of order 1 TeV and nominal couplings with quarks can generate the $CP$ asymmetries at the percent level. Using the experimental data on branching ratios and $CP$ asymmetries of $D^0\to ({\pi }^{+}{\pi }^{-},K^{+}{K}^{-})$, we derive the constraints on the diquark mass and couplings, which can be further examined in hadron colliders in the dijet final states.

In this paper, we present a new method to calculate the $n$-Loop $n$-particle irreducible effective action. The key is an organizational trick that involves the introduction of a set of fictitious bare vertices that are set to zero at the end of the calculation. Using these fictitious vertices, we prove that the Schwinger-Dyson equations are the same as the equations of motion obtained from the $n$-particle irreducible effective action, up to the level at which they respect the symmetries of the original theory. This result allows us to obtain the effective action directly from the Schwinger-Dyson equations, which are comparatively easy to calculate. As a check of our method, we reproduce the known results for the $n$-Loop $n$-particle irreducible effective action with $n=4$ and $n=5$. We also use the technique to calculate the 6-Loop 6-particle irreducible effective action.

In the minimal supersymmetric standard model, the scalar neutrino ${\tilde{\nu }}_L$ has odd $R$ parity, yet it has long been eliminated as a dark-matter candidate because it scatters elastically off nuclei through the $Z$ boson, yielding a cross section many orders of magnitude above the experimental limit. We show how it can be reinstated as a dark-matter candidate by splitting the masses of its real and imaginary parts in an extension of the minimal supersymmetric standard model with scalar triplets. As a result, radiative neutrino masses are generated. This severely constrains the $U(1)$ and $SU(2)$ gaugino masses as a function of the ${\tilde{\nu }}_L$ mass, which is bounded by the 2011 XENON100 data to be above 125 GeV. Whereas a $\tilde{\nu }-{\tilde{\nu }}^{*}$ asymmetry is created from the decay of a heavy scalar triplet together with a lepton asymmetry, it gets washed out by $\tilde{\nu }-{\tilde{\nu }}^{*}$ oscillations after the electroweak phase transition. However, ${\tilde{\nu }}_2$ then decays into ${\tilde{\nu }}_1\nu \overline{\nu }$ fast enough so that only ${\tilde{\nu }}_1$ survives as dark matter today.

Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the squark and gluino masses. We present an improved analysis of squark and gluino mass bounds which is based on state-of-the-art cross section calculations including the summation of large threshold corrections. For illustration, we consider experimental data obtained by the CDF collaboration at the Fermilab Tevatron and discuss the impact of the improved cross section predictions on the squark and gluino mass limits.

We study different top-quark charge asymmetries and the variation of $t\overline{t}$ total cross section induced by the effective axial-vector coupling of gluon in the LHC experiments. We show that rapidity-cut-dependent asymmetries are more sensitive to the new physics than the independent ones. We also study the dependence of the asymmetries and variations of total $t\overline{t}$ cross sections on the invariant mass of $t\overline{t}$ system and show that it would be necessary to measure those quantities as functions of $m_{tt}$ at the LHC. In the context of considered new physics scenario, 7 TeV LHC has enough sensitivity either to confirm the Tevatron top asymmetry anomaly or to rule it out. In the latter case, the LHC is able to put stringent constraints on the new physics scale $\Lambda$ in this framework.

Recent measurements of the inelastic and total proton-proton cross section at the LHC, and at cosmic ray energies by the Auger experiment, have quantitatively confirmed fits to lower energy data constrained by the assumption that the proton is asymptotically a black disk of gluons. We show that data on $\overline{p}(p)p$, ${\pi }^{\mp }p$, and $K^{\mp }p$ forward scattering support the related expectation that the asymptotic behavior of all cross sections is flavor independent. By using the most recent measurements from ATLAS, CMS, TOTEM, and Auger, we predict ${\sigma }_{\mathrm{tot}}^{pp}(\sqrt{s}=8\mathrm{TeV})=100.6\pm 2.9\mathrm{mb}$ and ${\sigma }_{\mathrm{tot}}^{pp}(\sqrt{s}=14\mathrm{TeV})=110.8\pm 3.5\mathrm{mb}$, as well as refine the total cross section ${\sigma }_{\mathrm{tot}}^{pp}(\sqrt{s}=57\mathrm{TeV})=139.6\pm 5.4\mathrm{mb}$. Our analysis also predicts the total ${\pi }^{\mp }{\pi }^{+}$ cross sections as a function of $\sqrt{s}$.

We study top-(anti)quark pair production at the Tevatron and Large Hadron Collider in the context of the minimal length scenario of the Arkani-Hamed, Dimopoulos and Dvali model of extra dimensions. We show that sizable effects onto both the integrated and differential cross section due to graviton mediation are expected for a string scale, $M_S$, of $\mathcal{O}(1–10\mathrm{TeV})$ and several extra dimensions, $\delta$, all compatible with current experimental constraints. Potential limits on $M_S$ are extracted. We also highlight clear phenomenological differences between a simple Arkani-Hamed, Dimopoulos and Dvali scenario and its modification based on using the minimal length scenario as a natural regulator for divergent amplitudes of virtual KK graviton exchange.

We consider the ($2+1$) flavor Polyakov quark-meson model and study the effect of including fermion vacuum fluctuations on the thermodynamics and phase diagram. The resulting model predictions are compared to the recent QCD lattice simulations by the HotQCD and Wuppertal-Budapest collaborations. The variation of the thermodynamic quantities across the phase transition region becomes smoother. This results in better agreement with the lattice data. Depending on the value of the mass of the sigma meson, including the vacuum term results in either pushing the critical end point into higher values of the chemical potential or excluding the possibility of a critical end point altogether.

The drag and diffusion coefficients of a hot hadronic medium consisting of pions, kaons and eta using open beauty mesons as a probe have been evaluated. The interaction of the probe with the hadronic matter has been treated in the framework of chiral perturbation theory. It is observed that the magnitude of both the transport coefficients is significant, indicating a substantial amount of interaction of the heavy mesons with the thermal bath. The results may have significant impact on the experimental observables like the suppression of single-electron spectra originating from the decays of heavy mesons produced in nuclear collisions at Relativistic Heavy Ion Collider and LHC energies.

We propose a new scenario in a radiative seesaw model based on $A_4$ flavor symmetry. In this model, we explore a possibility of linking nonzero ${\theta }_{13}$ to dark matter. And we analyze the lepton sector to predict the observed neutrinos and mixings, especially obtaining a lower bound of ${\theta }_{13}\gtrsim 3.5°$. We show that the nonzero ${\theta }_{13}$ is correlated with our heavy Majorana type of dark matter. Also we predict that the mass be $\mathcal{O}(1–10)\mathrm{TeV}$, as a result of analyzing the Wilkinson-Microwave-Anisotropy-Probe and lepton flavor violation.

Using a sample of $158\times {10}^6$ ${\rm Y}(2S)$ events collected with the Belle detector, we search for the first time for double-charmonium decays of the $P$-wave spin-triplet bottomonium states (${\rm Y}(2S)\to \gamma {\chi }_{bJ}$, ${\chi }_{bJ}\to J/\psi J/\psi$, $J/\psi {\psi }^{\prime }$, ${\psi }^{\prime }{\psi }^{\prime }$ for $J=0$, 1, and 2). No significant ${\chi }_{bJ}$ signal is observed in the double-charmonium mass spectra, and we obtain the following upper limits: $\mathcal{B}({\chi }_{bJ}\to J/\psi J/\psi )<7.1\times {10}^{-5}$, $2.7\times {10}^{-5}$, $4.5\times {10}^{-5}$, $\mathcal{B}({\chi }_{bJ}\to J/\psi {\psi }^{\prime })<1.2\times {10}^{-4}$, $1.7\times {10}^{-5}$, $4.9\times {10}^{-5}$, $\mathcal{B}({\chi }_{bJ}\to {\psi }^{\prime }{\psi }^{\prime })<3.1\times {10}^{-5}$, $6.2\times {10}^{-5}$, $1.6\times {10}^{-5}$ for $J=0$, 1, and 2, respectively, at the 90% confidence level. These limits are significantly lower than the central values (with uncertainties of 50% to 70%) predicted using the light cone formalism but are consistent with calculations using the nonrelativistic QCD (NRQCD) factorization approach.

We observe a correlation between the slope of radio lateral distributions and the mean muon pseudorapidity of 59 individual cosmic-ray-air-shower events. The radio lateral distributions are measured with LOPES, a digital radio interferometer colocated with the multidetector-air-shower array KASCADE-Grande, which includes a muon-tracking detector. The result proves experimentally that radio measurements are sensitive to the longitudinal development of cosmic-ray air showers. This is one of the main prerequisites for using radio arrays for ultra-high-energy particle physics and astrophysics.

Recent progress on scattering amplitudes has benefited from the mathematical technology of symbols for efficiently handling the types of polylogarithm functions which frequently appear in multiloop computations. The symbol for all two-loop maximally helicity violating amplitudes in planar supersymmetric Yang-Mills theory is known, but explicit analytic formulas for the amplitudes are hard to come by except in special limits where things simplify, such as multi-Regge kinematics. By applying symbology we obtain a formula for the leading behavior of the imaginary part (the Mandelstam cut contribution) of this amplitude in multi-Regge kinematics for any number of gluons. Our result predicts a simple recursive structure which agrees with a direct Balitsky-Fadin-Kuraev-Lipatov computation carried out in a parallel publication.

In this work, we employ renormalization group methods to study the general behavior of field theories possessing anisotropic scaling in the spacetime variables. The Lorentz symmetry breaking that accompanies these models are either soft, if no higher spatial derivative is present, or it may have a more complex structure if higher spatial derivatives are also included. Both situations are discussed in models with only scalar fields and also in models with fermions as a Yukawa-like model.

We discuss the choice of input parameters for the renormalization of the chargino and neutralino sector in the minimal supersymmetric standard model in the on-shell scheme. We show that one should choose the masses of a bino-like, a wino-like and a Higgsino-like state as inputs in order to avoid large corrections to the masses of the other eigenstates in this sector. We also show that schemes where the Higgsino-like input state is a neutralino are more stable than those where the mass of the Higgsino-like chargino is used as input. The most stable scheme uses the masses of the wino-like chargino as well as the masses of the bino- and Higgsino-like neutralinos as inputs.

The basis of our analysis is the observation of the simultaneous enhancements of the gamma ray and neutron fluxes detected in 2009–2010 during thunderstorm ground enhancements at the mountain altitude of 3200 m. We investigate the correlated time series of the gamma rays and neutrons measured by the surface particle detectors of Aragats Space Environmental Center. The photonuclear reactions of the gamma rays born in the runaway breakdown (RB, now referred to as relativistic runaway electron avalanche, RREA) process with air were considered as the main process responsible for the copious neutron production. We consider also the mesoatom nuclei decay as a possible source of the additional neutrons registered by the neutron monitor due to enhanced population of the negative muons accelerated in the thunderclouds.

In supersymmetric extensions of the standard model of particle physics (SM), goldstino superpartners—scalar and pseudoscalar sgoldstinos—can be light enough for emerging in decays of SM particles. Sgoldstino interaction with SM fields is suppressed by the scale of supersymmetry breaking in the whole theory. Hence, searches for sgoldstinos give an opportunity to probe the underlying mechanism of supersymmetry breaking. Sgoldstino couplings to SM fields are proportional to the supersymmetry breaking parameters—MSSM soft terms—and therefore can lead to flavor violating processes in quark and lepton sectors. We consider flavor violating processes involving sgoldstino pair production which are driven by sgoldstino couplings proportional to squark and slepton soft mass terms, ${\tilde{m}}_{LL}^2$ and ${\tilde{m}}_{RR}^2$. We find that present limits on off-diagonal entries in squark and slepton squared mass matrices allow $t$-, $b$-, $c$-quark and $\tau$-lepton decays at levels available for study with existing data (BaBar, Belle, CLEOc) and in ongoing experiments (LHCb, CMS, ATLAS). In particular, we obtain the following branching ratios $\mathrm{Br}(t\to cSP)\lesssim {10}^{-7}$, $\mathrm{Br}(\tau \to \mu SP)\lesssim {10}^{-7}$, $\mathrm{Br}(B_s\to SP)\lesssim {10}^{-4}$, $\mathrm{Br}(B\to K^{(*)}SP)\lesssim {10}^{-4}$, $\mathrm{Br}(D\to SP)\lesssim {10}^{-7}$ with sgoldstino subsequent decays into kinematically allowed pairs of SM particles $\gamma \gamma$, $e^{+}{e}^{-}$, ${\mu }^{+}{\mu }^{-}$, etc. Remarkably, the prominent signature of sgoldstino pair production is two muon pairs with pair momenta peaked at sgoldstino masses.

The production of the charmonium states in $p\overline{p}$ experiments is considered at the energy rates near the threshold in next to leading order. Such a consideration allows one to obtain nonzero distributions over the transverse momentum of the final charmonium and gives a natural explanation to the existence of the ${\chi }_{c1}$ meson in the final state, which is observed experimentally and cannot be produced in leading order processes. The question of scale dependence of theoretical predictions is discussed.