Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userComments on the Background Field Method in Harmonic Superspace: Non-holomorphic Corrections in N=4 SYM
50
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We analyse the one-loop effective action of N=4 SYM theory in the framework of the background field formalism in N=2 harmonic superspace. For the case of on-shell background N=2 vector multiplet we prove that the effective action is free of harmonic singularities. When the lowest N=1 superspace component of the N=2 vector multiplet is switched off, the effective action of N=4 SYM theory is shown to coincide with that obtained by Grisaru et al on the base of the N=1 background field method. We compute the leading non-holomorphic corrections to the N=4 SU(2) SYM effective action.
rate research
Read More
We compute the one-loop non-holomorphic effective potential for the N=4 SU(n) supersymmetric Yang-Mills theory with the gauge symmetry broken down to the maximal torus. Our approach remains powerful for arbitrary gauge groups and is based on the use of N=2 harmonic superspace formulation for general N=2 Yang-Mills theories along with the superfield background field method.
The background field method for N=2 super Yang-Mills theories in harmonic superspace is developed. The ghost structure of the theory is investigated. It is shown that the ghosts include two fermionic real omega-hypermultiplets (Faddeev-Popov ghosts) and one bosonic real omega-hypermultiplet (Nielsen-Kallosh ghost), all in the adjoint representation of the gauge group. The one-loop effective action is analysed in detail and it is found that its structure is determined only by the ghost corrections in the pure super Yang-Mills theory. As applied to the case of N=4 super Yang-Mills theory, realized in terms of N=2 superfields, the latter result leads to the remarkable conclusion that the one-loop effective action of the theory does not contain quantum corrections depending on the N=2 gauge superfield only. We show that the leading low-energy contribution to the one-loop effective action in the N=2 SU(2) super Yang-Mills theory coincides with Seibergs perturbative holomorphic effective action.
In this paper we develop a supersymmetric version of unitarity cut method for form factors of operators from the chiral truncation of the the $mathcal{N}=4$ stress-tensor current supermultiplet $T^{AB}$. The relation between the superform factor with supermomentum equals to zero and the logarithmic derivative of the superamplitude with respect to the coupling constant is discussed and verified at tree- and one-loop level for any MHV $n$-point ($n geq 4$) superform factor involving operators from chiral truncation of the stress-tensor energy supermultiplet. The explicit $mathcal{N}=4$ covariant expressions for n-point tree- and one-loop MHV form factors are obtained. As well, the ansatz for the two-loop three-point MHV superform factor is suggested in the planar limit, based on the reduction procedure for the scalar integrals suggested in our previous work. The different soft and collinear limits in the MHV sector at tree- and one-loop level are discussed.
In a {cal N}=1 superspace setup and using dimensional regularization, we give a general and simple prescription to compute anomalous dimensions of composite operators in {cal N}=4, SU(N) supersymmetric Yang-Mills theory, perturbatively in the coupling constant g. We show in general that anomalous dimensions are responsible for the appearance of higher order poles in the perturbative expansion of the two-point function and that their lowest contribution can be read directly from the coefficient of the 1/epsilon^2 pole. As a check of our procedure we rederive the anomalous dimension of the Konishi superfield at order g^2. We then apply this procedure to the case of the double trace, dimension 4, superfield in the 20 of SU(4) recently considered in the literature. We find that its anomalous dimension vanishes for all N in agreement with previous results.
In this paper we study the form factors for the half-BPS operators $mathcal{O}^{(n)}_I$ and the $mathcal{N}=4$ stress tensor supermultiplet current $W^{AB}$ up to the second order of perturbation theory and for the Konishi operator $mathcal{K}$ at first order of perturbation theory in $mathcal{N}=4$ SYM theory at weak coupling. For all the objects we observe the exponentiation of the IR divergences with two anomalous dimensions: the cusp anomalous dimension and the collinear anomalous dimension. For the IR finite parts we obtain a similar situation as for the gluon scattering amplitudes, namely, apart from the case of $W^{AB}$ and $mathcal{K}$ the finite part has some remainder function which we calculate up to the second order. It involves the generalized Goncharov polylogarithms of several variables. All the answers are expressed through the integrals related to the dual conformal invariant ones which might be a signal of integrable structure standing behind the form factors.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
