We show how to include in the existing calculations for nuclei other than ${}^{129}\mathrm{Xe}$ and ${}^{131}\mathrm{Xe}$ the corrections to the isovector coupling arising in chiral effective field theory recently found in Menendez et al. [Phys. Rev. D 86, 103511 (2012)]. The dominant, momentum-independent, two-body current effect can be taken into account by formally redefining the static spin matrix elements $⟨{\mathbf{S}}_{p,n}⟩$. By further using the normalized form factor at $q\ne 0$ built with the one-body level structure functions, we show that the weakly interacting massive particles (WIMP)-nucleus cross section and the upper limits on the WIMP-nucleon cross sections coincide with the ones derived by using the exact functions at the two-body level. We explicitly show it in the case of XENON100 limits on the WIMP-neutron cross section, and we recalculate the limits on the WIMP-proton spin-dependent cross section set by COUPP. We also give practical formulas to obtain $⟨{\mathbf{S}}_{p,n}⟩$ given the structure functions in the various formalisms and notations existing in the literature. We argue that the standard treatment of the spin-dependent cross section in terms of three independent isospin functions, $S_{00}(q)$, $S_{11}(q)$, and $S_{01}(q)$, is redundant in the sense that the interference function $S_{01}(q)$ is the double product $|S_{01}(q)|=2\sqrt{S_{00}(q)}\sqrt{S_{11}(q)}$ even when including the new effective field theory corrections.

We find out the connection between the unintegrated gluon distribution at low intrinsic transverse momenta and the inclusive spectrum of the hadrons produced in $pp$ collision at LHC energies in the midrapidity region and low hadron transverse momenta. The parameters of this distribution are found from the best description of the LHC data. Its application to the analysis of $ep$ deep inelastic scattering allows us to obtain the results that describe reasonably well the H1 and ZEUS data on the structure functions at low $x$. A connection between the soft processes at LHC and small $x$ physics at HERA has been found.

We study the M1 transitions of ground state heavy baryons within a framework of the modified bag model. Calculations of transition moments and corresponding M1 decay widths are performed. For the spin $\frac{1}{2}$ baryons containing three differently flavored quarks the hyperfine mixing effects are taken into account. Results are compared with estimates obtained using various other approaches.

Massive gravity, Galileon and braneworld models that modify gravity to explain cosmic acceleration utilize the nonlinear field interactions of the Vainshtein mechanism to screen fifth forces in high density regimes. These source-dependent interactions cause apparent equivalence principle violations. In the weakly screened regime violations can be especially prominent since the fifth forces are at near full strength. Since they can also be calculated perturbatively, we derive analytic solutions for the cubic Galileon: the motion of massive objects in compensated shells and voids and infall toward halos that are spherically symmetric. Using numerical techniques we show that these solutions are valid until the characteristic scale becomes comparable to the Vainshtein radius. We find a relative acceleration of more massive objects toward the center of a void and a reduction of the infall acceleration that increases with the mass ratio of the halos which can in principle be used to test the Vainshtein screening mechanism.

Inflection point inflation generically includes a deviation from slow-roll when the inflaton approaches the inflection point. Such deviations are shown to be generated by transitions between singular trajectories. The effects on the power spectrum are studied within the context of universality classes for small-field models. These effects are shown to scale with universality parameters, and can explain the anomalously low power at large scales observed in the cosmic microwave background. The reduction of power is related to the inflection point’s basin of attraction. Implications for the likelihood of inflation are discussed.

We investigate the dynamics of a closed Friedmann-Robertson-Walker universe and anisotropic Bianchi type-IX universe characterized by two scale factors in a gravity theory including a higher curvature (Gauss-Bonnet) term. The presence of the cosmological constant creates a critical point of saddle type in the phase space of the system. An orbit starting from a neighborhood of the separatrix will evolve toward the critical point, and it eventually either expands to the de Sitter space or collapses to the big crunch. In the closed Friedmann-Robertson-Walker model, the dynamics is reduced to hyperbolic motions in the two-dimensional center manifold, and the system is not chaotic. In the anisotropic model, anisotropy introduces the rotational mode, which interacts with the hyperbolic mode to present a cylindrical structure of unstable periodic orbits in the neighborhood of the critical point. Due to the nonintegrability of the system, the interaction of rotational and hyperbolic modes makes the system chaotic, making it impossible for us to predict the final fate of the universe. We find that the chaotic dynamics arises from the fact that orbits with even small perturbations around the separatrix oscillate in the neighborhood of the critical point before finally expanding or collapsing. The chaotic character is also evidenced by the fractal structures in the basins of attraction.

One natural way to understand the excess of the measured $H\to \gamma \gamma$ rate over the standard model expectation at the Large Hadron Collider (LHC) is to have charged scalar bosons, existing in most of the standard model extensions. Motivated by this LHC result, we explore whether it also sheds light on solving the small neutrino mass generation problem. We concentrate on a class of models with high-dimensional representations of scalars to realize Majorana neutrino masses at the two-loop level without imposing any new symmetry. In these models, multiscalars with electric charges higher than two are naturally expected, which not only enhance the $H\to \gamma \gamma$ rate, but provide more searching grounds at the LHC. In particular, the rate of $H\to Z\gamma$ also changes similar to that of the diphoton channel.

A first-order action for scalar-tensor theories of gravity is proposed. The Hamiltonian analysis of the action gives the desired connection dynamical formalism, which was derived from the geometrical dynamics by canonical transformations. It is shown that this connection formalism in the Jordan frame is equivalent to the alternative connection formalism in the Einstein frame. Therefore, the action principle underlying loop quantum scalar-tensor theories is recovered.

It was shown recently that a $\mathcal{P}\mathcal{T}$-symmetric $i{\varphi }^3$ quantum field theory in $6-ϵ$ dimensions possesses a nontrivial fixed point. The critical behavior of this theory around the fixed point is examined and it is shown that the corresponding phase transition is related to the existence of a nontrivial solution of the gap equation. The theory is studied first in the mean-field approximation and the critical exponents are calculated. Then, it is examined beyond the mean-field approximation by using renormalization-group techniques, and the critical exponents for $6-ϵ$ dimensions are calculated to order $ϵ$. It is shown that because of its stability the $\mathcal{P}\mathcal{T}$-symmetric $i{\varphi }^3$ theory has a higher predictive power than the conventional ${\varphi }^3$ theory. A comparison of the $i{\varphi }^3$ model with the Lee-Yang model is given.

In four-dimensional theories with massless particles, one-loop amplitudes can be expressed in terms of a basis of scalar integrals and rational terms. Since the scalar bubble integrals are the only UV divergent integrals, the sum of the bubble coefficients captures the one-loop UV behavior. In particular, in a renormalizable theory the sum of the bubble coefficients equals the tree-level amplitude times a proportionality constant that is related to the one-loop beta function coefficient ${\beta }_0$. In this paper, we study how this proportionality is achieved from the viewpoint of on-shell amplitudes. For $n$-point MHV amplitude in (super) Yang-Mills theory, we demonstrate the existence of a hidden structure in each individual bubble coefficient which directly leads to systematic cancellations within the sum of them. The origin of this structure can be attributed to the collinear poles within a two-particle cut. Due to the cancellation, the one-loop beta function coefficient can be identified as a sum over the residues of unique collinear poles in particular two-particle cuts. Using CSW recursion relations, we verify the generality of this statement by reproducing the correct proportionality factor from such cuts for $n$-point split-helicity ${\mathrm{N}}^k\mathrm{MHV}$ amplitudes.

In this paper, we study static post-Newtonian limits in nonprojectable Hořava-Lifshitz gravity with an extra U(1) symmetry. After obtaining all static spherical solutions in the infrared, we apply them to the Solar System tests, and obtain the Eddington-Robertson-Schiff parameters in terms of the coupling constants of the theory. These parameters are well consistent with observations for the physically viable coupling constants. In contrast to the projectable case, this consistence is achieved without taking the gauge field and Newtonian prepotential as part of the metric.

Compact objects, like neutron stars and white dwarfs, may accrete dark matter, and then be sensitive probes of its presence. These compact stars with a dark matter component can be modeled by a perfect fluid minimally coupled to a complex scalar field (representing a bosonic dark matter component), resulting in objects known as fermion-boson stars. We have performed the dynamical evolution of these stars in order to analyze their stability, and to study their spectrum of normal modes, which may reveal the amount of dark matter in the system. Their stability analysis shows a structure similar to that of an isolated (fermion or boson) star, with equilibrium configurations either laying on the stable or on the unstable branch. The analysis of the spectrum of normal modes indicates the presence of new oscillation modes in the fermionic part of the star, which result from the coupling to the bosonic component through the gravity.

We study the evolution of turbulence in the early Universe at the QCD epoch using a state-of-the-art equation of state derived from lattice QCD simulations. Since the transition is a crossover we assume that temperature and velocity fluctuations were generated by some event in the previous history of the Universe and survive until the QCD epoch due to the extremely large Reynolds number of the primordial fluid. The fluid at the QCD epoch is assumed to be nonviscous, based on the fact that the viscosity per entropy density of the quark gluon plasma obtained from heavy-ion collision experiments at the Relativistic Heavy Ion Collider and the LHC is extremely small. Our hydrodynamic simulations show that the velocity spectrum is very different from the Kolmogorov power law considered in studies of primordial turbulence that focus on first order phase transitions. This is due to the fact that there is no continuous injection of energy into the system and the viscosity of the fluid is negligible. Thus, as kinetic energy cascades from the larger to the smaller scales, a large amount of kinetic energy is accumulated at the smallest scales due to the lack of dissipation. We have obtained the spectrum of the gravitational radiation emitted by the motion of the fluid finding that, if typical velocity and temperature fluctuations have an amplitude $(\Delta v)/c\gtrsim {10}^{-2}$ and/or $\Delta T/T_c\gtrsim {10}^{-3}$, they would be detected by eLISA at frequencies larger than $\sim {10}^{-4}\mathrm{Hz}$.

We use the Lagrange-Noether methods to derive the conservation laws for models in which matter interacts nonminimally with the gravitational field. The nonminimal coupling function can depend arbitrarily on the gravitational field strength. The obtained result generalizes earlier findings. The generalized conservation laws provide the basis for the derivation of the equations of motion for the nonminimally coupled test bodies.

The sets of charged-lepton ($L$) and quark $(D,U)$ masses may be parametrized in a $Z_3$-symmetric language appropriate for the discussion of Koide’s formula. Experiment suggests that at the low-energy scale the relevant phase parameters ${\delta }_f$ take on possibly exact values of ${\delta }_L=3{\delta }_D/2=3{\delta }_U=2/9$. For $k_f$ (the other parameter relevant for the pattern of masses), a similarly simple expression ($k_L=1$) is known for charged leptons only. Using the Fritzsch-Xing decomposition of quark-mixing matrices, we show that the suggested pattern of low-energy quark masses is consistent with an earlier conjecture that $k_{D,U}\approx 1$ in the weak basis.

Phenomenological analysis to the $R$-parity violating supersymmetry with a vectorlike extra generation is performed in detail. It is found that, via the trilinear couplings, the correct neutrino spectrum can be obtained. The Higgs mass rises to 125 GeV by new up-type Yukawa couplings of vectorlike quarks with no need of very heavy superpartners. Phenomena of new heavy fermions at LHC are predicted.

Many particle physics models attempt to explain the 130 GeV gamma-ray feature that the Fermi large area telescope observes in the Galactic center. Neutralino dark matter in nonminimal supersymmetric models, such as the next-to-minimal supersymmetric standard Model (NMSSM), is an especially well-motivated theoretical setup that can explain the line. We explore the possibility that regions of the NMSSM consistent with the 130 GeV line can also produce the observed baryon asymmetry of the universe via electroweak baryogenesis. We find that such regions can, in fact, accommodate a strongly first-order electroweak phase transition (due to the singlet contribution to the effective potential), while also avoiding a light stop and producing a Standard Model (SM)-like Higgs in the observed mass range. Simultaneously, $CP$ violation from a complex phase in the wino-Higgsino sector can account for the observed baryon asymmetry through resonant sources at the electroweak phase transition, while satisfying current constraints from dark matter, collider, and electric dipole moment experiments. This result is possible by virtue of a relatively light pseudoscalar Higgs sector with a small degree of mixing, which yields efficient $s$-channel resonant neutralino annihilation consistent with indirect detection constraints, and of the moderate values of $\mu$ required to obtain a binolike lightest supersymmetric particle consistent with the line. The wino mass is essentially a free parameter that one can tune to satisfy electroweak baryogenesis. Thus, the NMSSM framework can potentially explain the origins of both baryonic and dark matter components in the Universe. The tightness of the constraints we impose on this scenario makes it extraordinarily predictive and conclusively testable in the near future by modest improvements in electric dipole moment and dark matter search experiments.

We study a number of different ingredients related to long range order observed in lattice QCD simulations, using a simple “deformed QCD” model. This model is a weakly coupled gauge theory, which, however, has all the relevant crucial elements, allowing us to study difficult and nontrivial problems which are known to be present in real, strongly coupled QCD. In the present study, we want to understand the physics of long range order in the form of coherent low-dimensional vacuum configurations observed in Monte Carlo lattice simulations. We demonstrate the presence of double-layer domain wall structures in the deformed QCD, and study their interaction with localized topological monopoles. Furthermore, we show that there is in fact an attractive interaction between the two, such that the monopole favors a position within the domain wall.