arXiv subjects

I. L. Buchbinder

Publications and source records attributed to I. L. Buchbinder.

At least 91 records · Page 5Linked to original sources

arXiv2017

Supergraph analysis of the one-loop divergences in $6D$, ${\cal N} = (1,0)$ and ${\cal N} = (1,1)$ gauge theories

We study the one-loop effective action for $6D,$ ${\cal N}=(1,0)$ supersymmetric Yang--Mills (SYM) theory with hypermultiplets and $6D,$ ${\cal N}=(1,1)$ SYM theory as a subclass of the former, using the off-shell formulation of these theories in $6D,$ ${\cal N}=(1,0)$ harmonic superspace. We develop the corresponding supergraph technique and apply it to compute the one-loop divergences in the background field method ensuring the manifest gauge invariance. We calculate the two-point Green functions of the gauge superfield and the hypermultiplet, as well as the three-point gauge-hypermultipet Green function. Using these Green functions and exploiting gauge invariance of the theory, we find the full set of the off-shell one-loop divergent contributions, including the logarithmic and power ones. Our results precisely match with those obtained earlier in [1,2] within the proper time superfield method.

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arXiv2017

"Induced" N=4 conformal supergravity

We consider an abelian N=4 super Yang-Mills theory coupled to background N=4 conformal supergravity fields. At the classical level, this coupling is invariant under global SU(1,1) transformation of the complex ("dilaton-axion") supergravity scalar combined with an on-shell vector-vector duality. We compute the divergent part of the corresponding quantum effective action found by integrating over the super Yang-Mills fields and demonstrate its SU(1,1) invariance. This divergent part related to the conformal anomaly is one-loop exact and should be given by the N=4 conformal supergravity action containing the Weyl tensor squared term. This allows us to determine the full non-linear form of the bosonic part of the N=4 conformal supergravity action which has manifest SU(1,1) invariance.

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arXiv2017

One-loop divergences in 6D, N=(1,0) SYM theory

We consider, in the harmonic superspace approach, the six-dimensional N=(1,0) supersymmetric Yang-Mills gauge multiplet minimally coupled to a hypermultiplet in an arbitrary representation of the gauge group. Using the superfield proper-time and background-field techniques, we compute the divergent part of the one-loop effective action depending on both the gauge multiplet and the hypermultiplet. We demonstrate that in the particular case of N=(1,1) SYM theory, which corresponds to the hypermultiplet in the adjoint representation, all one-loop divergencies vanish, so that N=(1,1) SYM theory is one-loop finite {\it off shell}.

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arXiv2016

One-loop divergences in the 6D, N=(1,0) abelian gauge theory

We consider, in the harmonic superspace approach, the six-dimensional N=(1,0) supersymmetric model of abelian gauge multiplet coupled to a hypermultiplet. The superficial degree of divergence is evaluated and the structure of possible one-loop divergences is analyzed. Using the superfield proper-time and background-field technique, we compute the divergent part of the one-loop effective action depending on both the gauge multiplet and the hypermultiplet. The corresponding counterterms contain the purely gauge multiplet contribution together with the mixed contributions of the gauge multiplet and hypermultiplet. We show that the theory is on-shell one-loop finite in the gauge multiplet sector in agreement with the results of [1]. The divergences in the mixed sector cannot be eliminated by any field redefinition, implying the theory to be UV divergent at one loop.

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arXiv2016

Unfolded equations for massive higher spin supermultiplets in AdS_3

In this paper we give an explicit construction of unfolded equations for massive higher spin supermultiplets of the minimal (1,0) supersymmetry in AdS_3 space. For that purpose we use an unfolded formulation for massive bosonic and fermionic higher spins and find supertransformations leaving appropriate set of unfolded equations invariant. We provide two general supermultiplets (s, s+1/2) and (s, s-1/2) with arbitrary integer s, as well as a number of lower spin examples.

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arXiv2016

Induced low-energy effective action in the 6D, N=(1,0) hypermultiplet theory on the vector multiplet background

We consider the six dimensional N=(1,0) hypermultiplet model coupled to an external field of the Abelian vector multiplet in harmonic superspace approach. Using the superfield proper-time technique we find the divergent part of the effective action and derive the complete finite induced low-energy superfield effective action. This effective action depends on external field and contains in bosonic sector all the powers of the constant Maxwell field strength. The obtained result can be treated as the 6D, N=(1,0) supersymmetric Heisenberg-Euler type effective action.

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arXiv2016

The low-energy N=4 SYM effective action in diverse harmonic superspaces

We review various superspace approaches to the description of the low-energy effective action in N=4 super Yang-Mills (SYM) theory. We consider the four-derivative part of the low-energy effective action in the Coulomb branch. The typical components of this effective action are the gauge field F^4/X^4 and the scalar field Wess-Zumino terms. We construct N=4 supersymmetric completions of these terms in the framework of different harmonic superspaces supporting N=2,3,4 supersymmetries. These approaches are complementary to each other in the sense that they make manifest different subgroups of the total SU(4) R-symmetry group. We show that the effective action acquires an extremely simple form in those superspaces which manifest the non-anomalous maximal subgroups of SU(4). The common characteristic feature of our construction is that we restore the superfield effective actions exclusively by employing the N=4 supersymmetry and/or superconformal PSU(2,2|4) symmetry.

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arXiv2015

BRST Analysis of the Supersymmetric Higher Spin Field Models

We develop the BRST approach for all massless integer and half-integer higher spins in 4D Minkowski space, using the two component spinor nota- tion and develop the Lagrangian formulation for supersymmetric higher spin models. It is shown that the problem of second class constraints disappears and the BRST procedure becomes much more simple than in tensorial nota- tion. Furthermore, we demonstrate that the BRST procedure automatically provides extra auxiliary components that belong in the set of supersymmetry auxiliary components. Finally, we demonstrate how supersymmetry transfo- rmations are realized in such an approach. As a result, we conclude that the BRST approach to higher spin supersymmetric theories allows to derive both the Lagrangian and the supersymmetry transformations. Although most part of the work is devoted to massless component supersymmetric models, we also discuss generalization for massive component supersymmetric models and for superfield models.

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arXiv2015

Effective actions in ${\cal N}$=1, D5 supersymmetric gauge theories: harmonic superspace approach

We consider the off-shell formulation of the 5D, $ {\cal N}$=1 super Yang-Mills and super Chern-Simons theories in harmonic superspace. Using such a formulation we develop a manifestly supersymmetric and gauge invariant approach to constructing the one-loop effective action both in super Yang-Mills and super Chern-Simons models. On the base of this approach we compute the leading low-energy quantum contribution to the effective action on the Abelian vector multiplet background. This contribution corresponds to $F^4$ invariant which is given in 5D superfield form.

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arXiv2015

Manifestly N=2 supersymmetric regularization for N=2 supersymmetric field theories

We formulate the higher covariant derivative regularization for N=2 supersymmetric gauge theories in N=2 harmonic superspace. This regularization is constructed by adding the N=2 supersymmetric higher derivative term to the classical action and inserting the N=2 supersymmetric Pauli--Villars determinants into the generating functional for removing one-loop divergencies. Unlike all other regularization schemes in N=2 supersymmetric quantum field theory, this regularization preserves by construction the manifest N=2 supersymmetry at all steps of calculating loop corrections to the effective action. Together with N=2 supersymmetric background field method this regularization allows to calculate quantum corrections without breaking the manifest gauge symmetry and N=2 supersymmetry. Thus, we justify the assumption about existence of a regularization preserving N=2 supersymmetry, which is a key element of the N=2 non-renormalization theorem. As a result, we give the prove of the N=2 non-renormalization theorem which does not require any additional assumptions.

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arXiv2015

Lagrangian formulation of the massive higher spin supermultiplets in three dimensional space-time

We give explicit construction for massive higher spin supermultiplets for the case of minimal supersymmetry in d=3 and find the corresponding Lagrangian formulations. We show that all such massive supermultiplets can be straightforwardly constructed out of the appropriately chosen set of massless ones exactly in the same way as the gauge invariant description for the massive bosonic (fermionic) field with spin s can be obtained using a set of massless fields with spins s,s-1,...,0(1/2). Moreover, such construction for the massive supermultiplets turns out to be perfectly consistent with our previous results on the gauge invariant Lagrangian formulation for massive higher spin bosons and fermions in d=3.

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arXiv2015

Quartic interaction vertex in the massive integer higher spin field theory in a constant electromagnetic field

We consider the massive integer higher spin fields coupled to an external constant electromagnetic field in flat space of arbitrary dimension and find a gauge invariant quartic interaction vertex which is quadratic in dynamical higher spin field and quadratic in external field. Construction of the vertex is based on the BRST approach to higher spin filed theory where no off-shell constraints on the fields and on the gauge parameters are imposed from the very beginning (unconstrained formulation).

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arXiv2015

On effective Kähler potential in N=2, d=3 SQED

We compute the two-loop effective Kähler potential in three-dimensional N=2 supersymmetric electrodynamics with Chern-Simons kinetic term for the gauge superfield. The effective action is constructed on the base of background field method with one parametric family of gauges. In such an approach, the quadratic part of quantum action mixes the gauge and matter quantum superfields yielding the complications in the computations of the loop supergraphs. To avoid this obstacle and preserve dependence on the gauge parameter we make a nonlocal change of quantum matter superfields after which the propagator is diagonalized, however the new vertices have appeared. We fix the suitable background and develop the efficient procedure of calculating the two-loop supergraphs with the new vertices. We compute the divergent and finite parts of the superfield effective action, find the two-loop effective Kähler potential and show that it does not depend on the gauge parameter.

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arXiv2015

Leading low-energy effective action in the 6D hypermultiplet theory on a vector/tensor background

We consider a six dimensional (1,0) hypermultiplet model coupled to an external field of vector/tensor system and study the structure of the low-energy effective action of this model. Manifestly a (1,0) supersymmetric procedure of computing the effective action is developed in the framework of the superfield proper-time technique. The leading low-energy contribution to the effective action is calculated.

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arXiv2015

Lagrangian formulation of massive fermionic higher spin fields on a constant electromagnetic background

We consider massive half-integer higher spin fields coupled to an external constant electromagnetic field in flat space of an arbitrary dimension and construct a gauge invariant Lagrangian in the linear approximation in the external field. A procedure for finding the gauge-invariant Lagrangians is based on the BRST construction where no off-shell constraints on the fields and on the gauge parameters are imposed from the very beginning. As an example of the general procedure, we derive a gauge invariant Lagrangian for a massive fermionic field with spin 3/2 which contains a set of auxiliary fields and gauge symmetries.

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arXiv2015

Construction of 6D supersymmetric field models in N=(1,0) harmonic superspace

We consider the six dimensional hypermultiplet, vector and tensor multiplet models in (1,0) harmonic superspace and discuss the corresponding superfield actions. The actions for free (2,0) tensor multiplet and for interacting vector/tensor multiplet system are constructed. Using the superfield formulation of the hypermultiplet coupled to the vector/tensor system we develop an approach to calculation of the one-loop superfield effective action and find its divergent structure.

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arXiv2014

Frame-like gauge invariant Lagrangian formulation of massive fermionic higher spin fields in AdS_3 space

We construct the frame-like gauge-invariant Lagrangian formulation for massive fermionic arbitrary spin fields in three-dimensional $AdS$ space. The Lagrangian and complete set of gauge transformations are obtained. We also develop the formalism of gauge-invariant curvatures for the massive theory under consideration and show how the Lagrangian is formulated in their terms. The massive spin-5/2 field is discussed as an example.

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arXiv2014

Formalism of gauge invariant curvatures and constructing the cubic vertices for massive spin-3/2 field in AdS_4 space

We study the interaction of massive spin-3/2 field with electromagnetic and gravitational fields in the four dimensional AdS space and construct the corresponding cubic vertices. Construction is based on generalization of Fradkin-Vasiliev formalism, developed for massless higher spin fields, to massive fermionic higher spin fields. The main ingredients of this formalism are the gauge invariant curvatures. We build such curvatures for the massive theory under consideration and show how the cubic vertices are written in their terms.

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