We study the conformal window of gauge theories containing fermionic matter fields, where the gauge group is any of the exceptional groups with the fermions transforming according to the fundamental and adjoint representations and the orthogonal groups where the fermions transform according to a spinorial representation. We investigate the phase diagram using a purely perturbative four-loop analysis, the all-orders beta function and the ladder approximation.

We evaluate the Barr-Zee-type two-loop level contribution to the fermion electric and chromo-electric dipole moments with sfermion loop in $R$-parity violating supersymmetric models. It is found that the Barr-Zee-type fermion dipole moment with sfermion loop acts destructively to the currently known fermion loop contribution, and that it has small effect when the mass of squarks or charged sleptons in the loop is larger than or comparable to that of the sneutrinos, but cannot be neglected if the sneutrinos are much heavier than loop sfermions.

We study effective theories of the axion in spontaneously broken supersymmetric theories. We consider a system where the axion supermultiplet is directly coupled to a supersymmetry-breaking sector, whereas the Standard Model sector is communicated with those sectors through loops of messenger fields. The gaugino masses and the axion-gluon coupling necessary for solving the strong $CP$ problem are both obtained by the same effective interaction. We discuss cosmological constraints on this framework.

Precision data generally require the threshold for physics beyond the Standard Model to be at the deca-TeV (10 TeV) scale or higher. This raises the question of whether there are interesting deca-TeV models for which the LHC may find direct clues. A possible scenario for such physics is a 5D warped model of fermion masses and mixing, with Kaluza-Klein masses $m_{\mathrm{KK}}\sim 10\mathrm{TeV}$, allowing it to avoid tension with stringent constraints, especially from flavor data. Discovery of a Standard-Model-like Higgs boson, for which there are some hints at $\sim 125\mathrm{GeV}$ at the LHC, would also require the Kaluza-Klein masses to be at or above 10 TeV. These warped models generically predict the appearance of a much lighter radion scalar. We find that, in viable warped models of flavor, a radion with a mass of a few hundred GeV and an inverse coupling of order $m_{\mathrm{KK}}\sim 10\mathrm{TeV}$ could typically be accessible to the LHC experiments—with $\sqrt{s}=14\mathrm{TeV}$ and $\sim 100{\mathrm{fb}}^{-1}$ of data. The above statements can be applied, mutatis mutandis, to 4D dual models, where conformal dynamics and a dilaton replace warping and the radion, respectively. Detection of such a light and narrow scalar could thus herald the proximity of a new physical threshold and motivate experiments that would directly probe the deca-TeV mass scale.

The LHC has started to constrain supersymmetry-breaking parameters by setting bounds on possible colored particles at the weak scale. Moreover, constraints from Higgs physics, flavor physics, the anomalous magnetic moment of the muon, as well as from searches at LEP and the Tevatron have set additional bounds on these parameters. Renormalization group invariants provide a very useful way of representing the allowed parameter space by making a direct connection with the values of these parameters at the messenger scale. Using a general approach, based on the phenomenological minimal supersymmetric standard model parametrization of the soft supersymmetry-breaking parameters, we analyze the current experimental constraints to determine the probability distributions for the renormalization group invariants. As examples of their application, we use these distributions to analyze the question of gaugino mass unification and to probabilistically determine the parameters of general and minimal gauge mediation with arbitrary Higgs mass parameters at the messenger scale.

We present a detailed assessment of uncertainties in parton-to-pion and parton-to-kaon fragmentation functions obtained in recent global QCD analyses of single-inclusive hadron production data at next-to-leading order accuracy. We use the robust Lagrange multiplier approach for determining uncertainties to validate the applicability of the simpler but approximate Hessian method. Extensive comparisons of the results obtained within both methods are presented for the individual parton-to-pion and kaon fragmentation functions. We provide Hessian eigenvector sets of pion and kaon fragmentation functions that allow one to easily propagate their uncertainties to any observable. Various applications of these sets are presented for pion and kaon production in electron-positron annihilation, lepton-nucleon scattering, and proton-proton collisions.

In the present paper we discuss the $P$-wave bottomonium production within both color octet and color singlet models in next-to-leading order at LHC energies. We calculate the cross section and the transverse momentum distributions for the ${\chi }_{1,2b}$ states. We obtain that the ratios of bottomonium and charmonium spin state production are fundamentally complementary at different $p_T$ scales. We give predictions for the ratio of the $n=2$ and $n=1$ radial excitations production cross sections.

We examine next-to-minimal supersymmetric model scenarios with partial parameter unification at the grand unification scale in which both $h_1$ and $h_2$ lie in the 123–128 GeV mass range. Very substantially enhanced $\gamma \gamma$ and other rates are possible. Broadened mass peaks are natural.

We present the general derivation of the full nonperturbative equation that governs the momentum evolution of the dynamically generated gluon mass, in the Landau gauge. The entire construction hinges crucially on the inclusion of longitudinally coupled vertices containing massless poles of nonperturbative origin, which preserve the form of the fundamental Slavnov-Taylor identities of the theory. The mass equation is obtained from a previously unexplored version of the Schwinger-Dyson equation for the gluon propagator, particular to the pinch technique-background field method formalism, which involves a reduced number of two-loop dressed diagrams, thus simplifying the calculational task considerably. The two-loop contributions turn out to be of paramount importance, modifying the qualitative features of the full mass equation and enabling the emergence of physically meaningful solutions. Specifically, the resulting homogeneous integral equation is solved numerically, subject to certain approximations, for the entire range of physical momenta, yielding positive-definite and monotonically decreasing gluon masses.

Recently, a recursion relation has been developed, generating the four-dimensional integrand of the amplitudes of $\mathcal{N}=4$ supersymmetric Yang-Mills theory for any number of loops and legs. In this paper, I provide a comparison of the prediction for the two-loop six-point maximally helicity-violating integrand against the result obtained by use of the leading singularity method. The comparison is performed numerically for a large number of randomly selected momenta and in all cases finds agreement between the two results to high numerical accuracy.

We study the phase transition of a real scalar ${\phi }^4$ theory in the two-loop $\Phi$-derivable approximation using the imaginary time formalism, extending our previous (analytical) discussion of the Hartree approximation. We combine fast Fourier transform algorithms and accelerated Matsubara sums in order to achieve a high accuracy. Our results confirm and complete earlier ones obtained in the real time formalism [A. Arrizabalaga and U. Reinosa, Nucl. Phys. A785, 234 (2007)] but which were less accurate due to the integration in Minkowski space and the discretization of the spectral density function. We also provide a complete and explicit discussion of the renormalization of the two-loop $\Phi$-derivable approximation at finite temperature, both in the symmetric and in the broken phase, which was already used in the real time approach, but never published. Our main result is that the two-loop $\Phi$-derivable approximation suffices to cure the problem of the Hartree approximation regarding the order of the transition: the transition is of the second order type, as expected on general grounds. The corresponding critical exponents are, however, of the mean-field type. Using a “renormalization group-improved” version of the approximation, motivated by our renormalization procedure, we find that the exponents are modified. In particular, the exponent $\delta$, which relates the field expectation value $\overline{\varphi }$ to an external field $h$, changes from 3 to 5, getting then closer to its expected value 4.789, obtained from accurate numerical estimates [A. Pelissetto and E. Vicari, Phys. Rept. 368, 549 (2002)].

We analyze the stability of the Euclidean Witten black hole (the cigar soliton in mathematics literature) under first-order renormalization group (Ricci) flow of the world-sheet sigma model. This analysis is from the target space point of view. We find that the Witten black hole has no unstable normalizable perturbative modes in a linearized mode analysis in which we consider circularly symmetric perturbations. Finally, we discuss a result from mathematics that implies the existence of a nonnormalizable mode of the Witten black hole under which the geometry flows to the sausage solution studied by Fateev, Onofri and Zamolodchikov.

We use nonlinear gauge-invariant perturbation theory to study the interaction of an inflation produced seed magnetic field with density and gravitational wave perturbations in an almost Friedmann-Lemaître-Robertson-Walker spacetime with zero spatial curvature. We compare the effects of this coupling under the assumptions of poor conductivity, perfect conductivity and the case where the electric field is sourced via the coupling of velocity perturbations to the seed field in the ideal magnetohydrodynamic regime, thus generalizing, improving on and correcting previous results. We solve our equations for long wavelength limits and numerically integrate the resulting equations to generate power spectra for the electromagnetic field variables, showing where the modes cross the horizon. We find that the interaction can seed electric fields with nonzero curl and that the curl of the electric field dominates the power spectrum on small scales, in agreement with previous arguments.

Very recently, it was pointed out that there exists a population of gamma-ray sources without associations at other wavelengths which exhibit spectral features consistent with monoenergetic lines at energies of approximately 111 and 129 GeV. Given recent evidence of similar gamma-ray lines from the inner Galaxy, it is tempting to interpret these unassociated sources as nearby dark matter subhalos, powered by ongoing annihilations. In this paper, we study the spectrum, luminosity, and angular distribution of these sources, with the intention of testing the hypothesis that they are, in fact, dark matter subhalos. We find that of the 12 sources containing at least one prospective line photon, only 2 exhibit an overall gamma-ray spectrum which is consistent with that predicted from dark matter annihilations (2FGL $\mathrm{J}2351.6-7558$ and 2FGL $\mathrm{J}0555.9-4348$). After discounting the 10 clearly non-dark-matter sources, the statistical significance of the remaining two prospective line photons is negligible. That being said, we cannot rule out the possibility that either or both of these sources are dark matter subhalos; their overall luminosity and galactic latitude distribution are not inconsistent with a dark matter origin.

We consider a generalization of the Randall-Sundrum single brane-world scenario (RS2). More precisely, the generalization is described through curvature corrections, corresponding to a Gauss-Bonnet term in the bulk and a Hilbert-Einstein term, as well as the strength of the induced gravity term, on the brane. We are mainly interested in analyzing the early inflationary era of the brane, which we model within the extreme slow-roll limit, i.e., under a de Sitter-like brane inflation, where the inflaton field is confined on the brane. We compute the scalar perturbations in this model and compare our results with those previously obtained for the RS2 scenario with and without an induced gravity term on the brane or a Gauss-Bonnet term in the bulk. The amplitude of the scalar perturbations is decreased as compared with a pure RS2 model. In addition, the effect from the Gauss-Bonnet correction in an induced gravity brane-world model is to decrease the amplitude of the scalar perturbations, and a similar result is obtained for the induced gravity effect in a Gauss-Bonnet brane world. In general, in the high energy limit the amplitude is highly suppressed by the Gauss-Bonnet effect. Finally, we constrain the model using the latest WMAP7 data.

We calculate the binding energies for multinucleon bound states with the nuclear mass number less than or equal to 4 in $2+1$ flavor QCD at the lattice spacing of $a=0.09\mathrm{fm}$ employing a relatively heavy quark mass corresponding to $m_{\pi }=0.51\mathrm{GeV}$. To distinguish a bound state from attractive scattering states, we investigate the volume dependence of the energy shift between the ground state and the state of free nucleons by changing the spatial extent of the lattice from 2.9 to 5.8 fm. We conclude that ${}^4\mathrm{He}$, ${}^3\mathrm{He}$, deuteron and dineutron are bound at $m_{\pi }=0.51\mathrm{GeV}$. We compare their binding energies with those in our quenched studies and also with several previous investigations.

We present a dimensionally deconstructed model of an $s$-wave holographic superconductor. The $2+1$ dimensional model includes multiple charged Cooper pair fields and neutral exciton fields that have interactions governed by hidden local symmetries. We derive AdS/CFT-like relations for the current and charge density in the model, and we analyze properties of the Cooper pair condensates and the complex conductivity.

The perturbative solution to the semiclassical Einstein field equations with a positive cosmological constant describing a static and spherically symmetric family of charged black holes for which the temperature of the event horizon equals the temperature of the cosmological horizon is constructed. The source term of the equations is the sum of the stress-energy tensor of the electromagnetic field and the renormalized stress-energy tensor of the quantized spinor and vector fields in a large mass limit, constructed within the framework of the Schwinger-DeWitt method. The main characteristics of the quantum-corrected black holes are calculated and expressed in terms of the horizon radii of the unperturbed problem. It is shown that the quantized fields tend to increase the temperature of the lukewarm black hole. The corrections to the event horizon are always negative, whereas the analogous corrections to the cosmological horizon are always positive. This behavior may be contrasted with that of the scalar field, which strongly depends on the coupling parameter. The renormalized stress-energy tensor of the massive spinor and vector field in general static and spherically symmetric geometry is presented. The related problem of charged black holes in quadratic gravity with a cosmological constant is briefly discussed.