Order G4 Research Articles

More fermionic supersymmetric Wilson loops in four dimensions

We construct supersymmetric fermionic Wilson loops along general curves in four-dimensional N=4 super Yang-Mills theory and along general planar curves in N=2 superconformal SU(N)×SU(N) quiver theory. These loops are generalizations of the Zarembo loops and are cohomologically equivalent to them. In N=4 super Yang-Mills theory, we compute their expectation values and verify the cohomological equivalence relation up to the order g4 in perturbation theory.

Two loop ghost free quantisation of Wilson loops in [formula omitted] supersymmetric Yang-Mills

We report a perturbative calculation of the expectation value of the infinite straight line Maldacena-Wilson loop in N=4 supersymmetric Yang-Mills theory to order g6. Thus, we extend the previous perturbative result by one order. The vacuum expectation value is reformulated in terms of a non-linear and non-local transformation, the Nicolai map, mapping the full functional measure of the interacting theory to that of a free bosonic theory. The results are twofold. The perturbative cancellations of the different contributions to the Maldacena-Wilson loop are by no means trivial and seem to resemble those of the circular Maldacena-Wilson loop at order g4. Furthermore, we argue that our approach to computing quantum correlation functions is competitive with more standard diagrammatic techniques.

Magnetically-treated brackish water affects soil water-salt distribution and the growth of cotton with film mulch drip irrigation in Xinjiang, China

Magnetically-treated brackish water can physically improve the quality of water used for irrigation. When combined with drip irrigation and mulching, this strategy can be valuable for agricultural production in arid and semi-arid areas. To evaluate the effects of magnetically-treated brackish water on soil water-salt distribution and cotton growth in Xinjiang, field experiments were conducted in 2017 and 2018 with magnetically-treated brackish water of five magnetization intensities: 0 Gs (CK), 1000 Gs (G1), 2000 Gs (G2), 4000 Gs (G4), and 5000 Gs (G5). The results showed that magnetically-treated brackish water (2.7 g L−1 (EC: 0.6 dS m−1)) could enhance soil water retention, promote root water absorption, and improve water productivity (WP). Magnetically-treated brackish water with 4000 Gs intensity showed the greatest improvement in water retention in the 0–100 cm soil layer. The average salt content in the soil irrigated with magnetically-treated brackish water of different intensities was in the order G4 <G2 <G5 <G1 <CK, indicating that magnetically-treated brackish water can effectively reduce the salt content and promote salt leaching. The desalinization rate, cotton yield, and WP were highest when the magnetization intensity was 4000 Gs, followed by 2000 Gs, which helped to alleviate the shortage of freshwater resources and reduce the risk of soil salinization. This study could provide a method for using brackish water safely and serve as a theoretical guide for water-saving and cotton yield increase in Xinjiang, China.

N3LO gravitational spin-orbit coupling at order G4

In this paper we derive for the first time the N3LO gravitational spin-orbit coupling at order G4 in the post-Newtonian (PN) approximation within the effective field theory (EFT) of gravitating spinning objects. This represents the first computation in a spinning sector involving three-loop integration. We provide a comprehensive account of the topologies in the worldline picture for the computation at order G4. Our computation makes use of the publicly-available EFTofPNG code, which is extended using loop-integration techniques from particle amplitudes. We provide the results for each of the Feynman diagrams in this sector. The three-loop graphs in the worldline picture give rise to new features in the spinning sector, including divergent terms and logarithms from dimensional regularization, as well as transcendental numbers, all of which survive in the final result of the topologies at this order. This result enters at the 4.5PN order for maximally-rotating compact objects, and together with previous work in this line, paves the way for the completion of this PN accuracy.

New findings on the d(TGGGAG) sequence: Surprising anti-HIV-1 activity

The biological relevance of tetramolecular G-quadruplexes especially as anti-HIV agents has been extensively reported in the literature over the last years. In the light of our recent results regarding the slow G-quadruplex folding kinetics of ODNs based on d(TGGGAG) sequence, here we report a systematic anti-HIV screening to investigate the impact of the G-quadruplex folding on their anti-HIV activity. In particular, varying the single stranded concentrations of ODNs, it has been tested a pool of ODN sample solutions with different G-quadruplex concentrations. The anti-HIV assays have been designed favouring the limited kinetics involved in the tetramolecular G4-association based on the d(TGGGAG) sequence. Aiming to determine the stoichiometry of G-quadruplex structures in the same experimental conditions of the anti-HIV assays, a native gel electrophoresis was performed. The gel confirmed the G-quadruplex formation for almost all sample solutions while showing the formation of high order G4 structures for the more concentrated ODNs solutions. The most significant result is the discovery of a potent anti-HIV activity of the G-quadruplex formed by the natural d(TGGGAG) sequence (IC50 = 14 nM) that, until now, has been reported to be completely inactive against HIV infection.

Charm quark effects on the strong coupling extracted from the static force

We compute the fermionic contribution to the strong coupling αqq extracted from the static force in Lattice QCD up to order g4 in perturbation theory. This allows us to subtract the leading fermionic lattice artifacts from recent determinations of αqq produced in simulations of two dynamical charm quarks. Moreover, by using a suitable parametrization of the βqq-function, we can evaluate the charm loop effects on αqq in the continuum limit.

Perturbative contributions to Wilson loops in twisted lattice boxes and reduced models

We compute the perturbative expression of Wilson loops up to order g4 for SU(N ) lattice gauge theories with Wilson action on a finite box with twisted boundary conditions. Our formulas are valid for any dimension and any irreducible twist. They contain as a special case that of the 4-dimensional Twisted Eguchi-Kawai model for a symmetric twist with flux k. Our results allow us to analyze the finite volume corrections as a function of the flux. In particular, one can quantify the approach to volume independence at large N as a function of flux k. The contribution of fermion fields in the adjoint representation is also analyzed.

Etidronate causes minimal changes in the ability of sodium hypochlorite to dissolve organic matter.

To evaluate the effect of individual and combined use of sodium hypochlorite (NaOCl), etidronate (HEDP) and ethylenediaminetetraacetic acid (EDTA) in tissue dissolution. Sixty fragments of bovine muscle tissue were prepared and their weights determined on a precision scale. The samples were then distributed in the following groups (n=10): G1 - saline solution (control); G2 - 17% EDTA; G3 - 18% HEDP; G4 - 2.5% NaOCl; G5 - mixture of 5% NaOCl+17% EDTA; and G6 - mixture of 5% NaOCl+18% HEDP. The specimens in each group were immersed in the solutions for 5, 10 and 15min and reweighted at each time period. Analysis of variance (anova) and Tukey's multiple-comparison tests (α<0.05) were applied to identify the intragroup and intergroup differences. G1, G2, G3 and G5 did not dissolve the organic matter. G4 and G6 significantly reduced the weights of specimens at all periods. Amongst the groups, the difference in ability to dissolve organic matter was greater and significant in the following order G4=G6>G5=G3=G2=G1 after 5min of immersion and G4>G6>G5=G3=G2=G1 after 10 and 15min of immersion. The only solution capable of dissolving organic matter was NaOCl. In the mixtures analysed, this ability was arrested by EDTA; however, it was minimally affected by the HEDP, proving that this combination, if used during the biomechanical preparation, is able to dissolve of organic matter.

Correlators of supersymmetric Wilson-loops, protected operators and matrix models in 𝒩 = 4 SYM

We study the correlators of a recently discovered family of BPS Wilson loops in = 4 supersymmetric U(N) Yang-Mills theory. When the contours lie on a two-sphere in the space-time, we propose a closed expression that is valid for all values of the coupling constant g and for any rank N, by exploiting the suspected relation with two-dimensional gauge theories. We check this formula perturbatively at order (g4) for two latitude Wilson loops and we show that, in the limit where one of the loops shrinks to a point, logarithmic corrections in the shrinking radius are absent at (g6). This last result strongly supports the validity of our general expression and suggests the existence of a peculiar protected local operator arising in the OPE of the Wilson loop. At strong coupling we compare our result to the string dual of the = 4 SYM correlator in the limit of large separation, presenting some preliminary evidence for the agreement.

Antiparticle Contribution in the Cross Ladder Diagram for Bethe-Salpeter Equation in the Light-Front

We construct the homogeneous integral equation for the vertex of the bound state in the light front with the kernel approximated to order g 4. We will truncate the hierarchical equations from Green functions to construct dynamical equations for the two boson bound state exchanging interacting intermediate σ bosons and including pair creation process contributing to the crossed ladder diagram.

Unified description of deconfined QCD equation of state

Several distinct perturbative approaches exist to describe the equation of state of QCD in the deconfined phase: dimensional reduction works for temperatures larger than the screening mass, otherwise one has to apply HDL/HTL resummation schemes at small temperatures or resort to the result by Freedman and McLerran at zero temperature. We present a new method that unifies these approaches in a manifestly four-dimensional calculation. We work out our new method for the pressure up to and including order g4 and verify that it agrees to the previous approaches in their respective ranges of validity.

Self-consistent nonperturbative anomalous dimensions

A self-consistent treatment of two- and three-point functions in models with trilinear interactions forces them to have opposite anomalous dimensions. We indicate how the anomalous dimension can be extracted nonperturbatively by solving and suitably truncating the topologies of the full Dyson–Schwinger set of equations. The first step requires a sensible ansatz for the full vertex part, which conforms to first order perturbation theory at least. We model this vertex to obtain typical transcendental relations between anomalous dimension and coupling constant g which coincide with known results to order g4.

Four-point correlators of BPS operators in [formula omitted] SYM at order g4

We study the large N degeneracy in the structure of the four-point amplitudes of 1 2 -BPS operators of arbitrary weight k in perturbative N=4 SYM theory. At one loop (order g 2) this degeneracy manifests itself in a smaller number of independent conformal invariant functions describing the amplitude, compared to AdS 5 supergravity results. To study this phenomenon at the two-loop level (order g 4) we consider a particular N=2 hypermultiplet projection of the general N=4 amplitude. Using the formalism of N=2 harmonic superspace we then explicitly compute this four-point correlator at two loops and identify the corresponding conformal invariant functions. In the cases of 1 2 -BPS operators of weight k=3 and k=4 the one-loop large N degeneracy is lifted by the two-loop corrections. However, for weight k>4 the degeneracy is still there at the two-loop level. This behavior suggests that for a given weight k the degeneracy will be removed if perturbative corrections of sufficiently high order are taken into account. These results are in accord with the AdS/CFT duality conjecture.

Finite temperature effective potential to order g4, λ2 and the electroweak phase transition

The standard model effective potential is calculated at finite temperature to order g 4, λ 2 and a complete zero temperature renormalization is performed. In comparison with lower order calculations the strength of the first order phase transition has increased dramatically. This effect can be traced back to infrared contributions from typical non-Abelian diagrams and to the infrared behaviour of the scalar sector close to the critical temperature. Several quantities, e.g. surface tension, latent heat and field expectation value are analysed for an SU(2)-Higgs model and for the full standard model in detail. An explicit formula enabling further analytic or numerical study is presented.

13C nuclear magnetic resonance relaxation-derived psi, phi bond rotational energy barriers and rotational restrictions for glycine 13C alpha-methylenes in a GXX-repeat hexadecapeptide.

Spin-lattice relaxation of 13C multiplet spectra and [1H]-13C nuclear Overhauser enhancement (NOE) coefficients of selectively 13C-enriched glycines in a collagen GXX-repeat motif hexadecapeptide, G1VKG4DKG7NPG10WPG13APY, has been investigated. Data have been collected at two 13C Larmor frequencies (90 and 150 MHz) over the temperature range from 5 to 70 degrees C. Relaxation data indicate that the most restricted internal rotations are at G7 and G10. Mobility of other glycine residues can be arranged in the order G4, G13, and G1. G1 glycine shows that least change in motional anisotropy with temperature. Several motional models have been used to explain the experimental data. While any one model is not completely satisfactory in describing all experimental parameters, only the model of restricted internal diffusion yields the observed positive sign for the cross-correlated spectral densities. Energetic and angular limits of psi, phi bond rotational motions derived from relaxation data and the restricted diffusion model are in good agreement with those calculated as Ramachandran potentional energy profiles. G1 rotational energy barriers for overall tumbling and internal rotation are approximately equal, suggesting strong interaction between the N-terminus and water. Internal rotational parameters for GV and GG dipeptides confirm this view. Nonterminal glycine internal motions are apparently less dependent on water-peptide interactions.

Gauge invariance and the prescription for the axial denominator

Gauge invariance of the Wilson loop is demonstrated by means of straightforward calculations in order g4 in the axial gauge, incuding the light-like one. The result does not depend on the prescription for the axial denominator and, as a consequence, it is not necessary to introduce the terms violating the translational invariance into the gluon propagator, or to modify the standard Feynman rules.

A quasi-temporal gauge

We prove that a complete fixing of the temporal gauge,A o =0, in which one imposesa subsidiary gauge condition, such as, for instance ∂i A i (x,t 0) = 0 leads to consistent formulation of the theory with simple Feynman rulesand a well defined gluon propagator. The correct exponentiation of the time dependence of the Wilson loop has been checked to occur up to order g4.

Two‐loop Renormalization of Non‐smooth String Operators in Yang‐Mills Theory

AbstractThe renormalization constants for string operators both with smooth and non‐smooth non‐self‐intersecting open contour have been evaluated up to the order g4.

The Wilson Loop in a Physical Gauge

We determine the static potential between non abelian charges at order g4 by computing the Wilson loop, for a rectangular loop in the large-T limit. We use a physical gauge obtained from the A0 = 0 gauge by integrating over the longitudinal components of the vector potential.

Definition and Use of Ferromagnon Annihilation Operators in the Bloch‐Dyson Theory of Ferromagnons

AbstractBy generalizing the Pauli‐operators, within the framework of Dyson's theory, ferromagnon annihilation operators are introduced. Using these operators the magnetization is determined for general S. The theory includes the kinematic interactions exactly, and the dynamic interactions are treated to various degrees of approximation. It is established that at low temperatures the dynamic interactions appear in the form of a term of order 𝔤4, while the kinematic interactions contribute a term of order 𝔤3 for S = 1/2, and of higher order than 𝔤4 for S &gt; 1/2.