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I. L. Buchbinder

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

At least 19 recordsLinked to original sources

Supersymmetry at BLTP: Recent Progress in Two Directions

Ten years ago, in a paper \cite{60}, a brief historical survey of the research activity in the Sector ``Supersymmetry'' at the Bogoliubov Laboratory of Theoretical Physics (BLTP) for more than 50 years of its existence has been given. Here, in commemoration of the 70th jubilee of Joint Institute for Nuclear Research, we review some recent sound advancements in this area. Specifically, we consider the issues of constructing the superfield quantum effective actions in $6D, {\cal N}=(1,0)$ supersymmetry and off-shell unconstrained superfield formulations of ${\cal N}=2$ higher spins. In both cases, the harmonic superspace approach plays the decisive role.

hep-th

One-loop finiteness in higher-derivative $6D$, ${\cal N}=(1,0)$ super Yang-Mills -- hypermultiplet system

We employ the harmonic superspace methods to study a six-dimensional $\mathcal{N}=(1,0)$ supersymmetric gauge theory with higher derivatives coupled to a hypermultiplet in the adjoint representation. By introducing a novel non-minimal interaction between the gauge multiplet and the hypermultiplet, we demonstrate that the one-loop divergences in gauge superfield sector, which are present in the conventional formulation, are canceled. The resulting theory is off-shell one-loop finite in this sector, while preserving the gauge invariance and $\mathcal{N}=(1,0)$ supersymmetry. The cancelation mechanism is explicitly verified using both the background field method and the supergraph techniques. Thus, we present an example of the higher-derivative supersymmetric gauge theory in six dimensions which is finite in the vector multiplet sector.

hep-th

On a quantization of deformed reducible gauge theories

We consider a general reducible gauge theory deformed by mass or/and interaction terms violating gauge invariance. It is shown that in the Abelian case, by using the Stueckelberg-type procedure, this theory with broken gauge symmetry can be converted into exactly gauge-invariant theory which under a suitable choice of gauge conditions can be treated within the formalism of minimal wave operators manageable by the covariant Schwinger-DeWitt technique. We carry out quantization of such a theory in general terms when the initial generators of gauge transformations are of the first and second stages of reducibility and derive its partition function in terms of the functional integral with all corresponding ghost fields. This method is applied to quantization of massive fermionic totally antisymmetric tensor field models in $AdS$ space. One-loop quantum effective action for these models is derived in the form of the functional determinants of special Dirac-type differential operators in various dimensions.

hep-th

On BRST Lagrangian description of partially massless bosonic fields

We present an exhaustive BRST lagrangian description of partially massless bosonic fields in four-dimensional space. The basic fields are formulated in terms of two-component spin-tensors in (A)dS space where the tracelessness conditions are automatically fulfilled. The mass shell of partially massless fields is reformulated in terms of constraints on Fock space vectors including the second-class constraints. A conversion procedure for transforming second-class constraints into first-class ones is developed, allowing one to construct a Hermitian and nilpotent BRST charge in the Fock space under consideration. It is proven that the hermiticity and nilpotency restrict the conditions on the theory parameters, which are fulfilled only in dS space. The hermiticity of the BRST charge is incompatible with AdS space. The gauge invariant Lagrangian is constructed on the basis of the BRST charge, and for spin $s$ and depth $t$ the allowed states in the Lagrangian include only $(s-t-1)$ Stückelberg fields. Their exclusion leads to gauge transformations of degree $(s-t)$ for the physical fields. The Lagrangian equations of motion exactly reproduce the mass shell conditions. The Lagrangian in terms of conventional spin-tensor fields is also presented.

hep-th

Chiral effective potential in $4D$, $\mathcal{N}=4$ SYM theory

We consider $4D$, $\mathcal{N}=4$, $SU(N)$ super Yang-Mills theory formulated in terms of $\mathcal{N}=1$ superfields where the leading low-energy contributions to effective action are given by chiral effective potential. This effective potential is calculated in one- and higher-loop approximations. It is shown that this potential is automatically finite and proportional to the classical chiral potential. All quantum corrections are found explicitly and factored into a coefficient at the classical potential.

hep-th

Continuous spin superparticle in $4D$, ${\cal N}=1$ curved superspace

We present a new particle model that describes the dynamics of a $4D,$ $\mathcal{N}{=}\,1$ continuous spin particle in $AdS_4$ superspace and is a generalization of the continuous-spin superparticle model in flat $4D$, $\mathcal{N}{=}\,1$ superspace proposed in 2506.19709 [hep-th]. The model is described by $4D$, $\mathcal{N}{=}\,1$ superspace coordinates together with commuting spinor additional variables, which are inherent ingredients of continuous spin models. The Lagrangian and the system of four bosonic and four fermionic phase space constraints are derived. The consistency condition for constraints imposes a restriction on supergeometry to be $AdS$ superpace. It is shown that the bosonic constraints are first-class constraints. A covariant procedure based on the use of additional variables is developed to divide the four fermionic constraints into first and second classes. It is proved that, unlike the flat case, only one fermionic constraint is a first-class constraint, while the other three are second-class constraints. In the flat limit, one of these second-class constraints becomes a first-class one.

hep-th

Covariant quantization of totally antisymmetric tensor-spinor field in $AdS_d$

We develop the quantization of a recently proposed model describing a totally antisymmetric rank-$p$ tensor-spinor field (a fermionic $p$-form theory) in $d$-dimensional anti-de Sitter (AdS) space. The model provides a new nontrivial example of a reducible gauge theory, in which gauge transformations are linearly dependent and the degree of reducibility increases with $p$. It is well known that in such cases the standard Faddeev-Popov-DeWitt prescription for the generating functional is not applicable. We quantize the fermionic $p$-form theory using the general Batalin-Vilkovisky (BV) formalism, employing two distinct gauge fermions associated with gauge-fixing functions of different admissible ranks, confirming the independence from the gauge choice. As a result, we obtain the quantum effective action in terms of a sequence of functional determinants corresponding to specific Dirac-like operators on AdS space.

hep-th

Chiral effective potential in $4D$, $\mathcal{N}=1$ supersymmetric gauge theories

We calculate the chiral effective superpotential in $4D$ $\mathcal{N}=1$, $SU(N)$ super Yang-Mills theory coupled to chiral matter in one- and two-loop approximations. It is found that the one-loop contribution to the chiral effective potential is always finite and is expressed in terms of a specific triangle integral. The two-loop contributions generated by purely chiral vertices turned out to be finite as well. The chiral effective potential stipulated by supergraphs with gauge superfield subgraphs is finite for the supergraphs with no divergent subgraphs. In the case of the finite $\mathcal{N}=2$ SYM theory, the two-loop chiral contributions to the effective action are significanlty simplified. The leading large $N$ behavior of the chiral effective superpotential in finite $\mathcal{N}=2$ super-Yang-Mills models with $SU(N)$ gauge symmetry is studied and it is shown that the exact form in the coupling constant of the chiral effective superpotential can be found.

hep-th

Continuous spin superparticle model

We construct a new model of a particle propagating in $4D$, ${\cal N}=1$ superspace that describes the dynamics of a continuous spin irreducible representation of the Poincaré supergroup. The model is characterized by two-component Weyl spinor additional even variables playing the role of extra coordinates. A canonical formulation, specific local fermionic $κ$-symmetry, and a compete system of bosonic and fermionic constraints are derived. All bosonic constrains are first-class, while fermionic constraints are a mixture of first and second classes. Using additional variables inherent in to the model, we split the fermionic constraints into first and second classes in a covariant way. Quantization of the model is carried out according to Dirac prescription imposing all the first-class constraints and half of the second-class constraints (Gupta-Bleuler procedure) on the wave function. At quantization, the fermionic constraints are written in terms of spinor supercovariant derivatives acting on superfields. The corresponding wave function, which is either a chiral or antichiral superfield, depends on additional variables and obeys the superfield constraints that define the continuous spin irreducible representation of the Poincaré supergroup in the superspace.

hep-th

Adjustment of Faddeev-Popov quantization to reducible gauge theories: antisymmetric tensor fermion in $AdS_d$ space

We develop the method adjusting the Faddeev-Popov factorization procedure for the quantization of generic reducible gauge theories with linearly dependent generators and apply it to the first stage reducible model of second rank antisymmetric fermion in d-dimensional AdS spacetime. The method consists in nested factorizations of the gauge group volume for the determination of the consistently defined delta function of reduced gauge conditions, group integration measure and gauge-fixed contribution of ghosts. It is compared to the Batalin-Vilkovisky (BV) formalism of quantizing theories with linearly dependent generators and shown to be equivalent to it for first stage reducible theories. Nevertheless, the method under consideration, unlike the BV formalism, from the very beginning leads to the functional integral with fewer number of ghosts. Using this method we quantized the variant of fermionic totally antisymmetric tensor-spinor theory in AdS space and derived its effective action in terms of the functional determinants of special Dirac-type operators. Limitations of the method are also discussed along with the prospects of its extension to higher reducibility stages and higher rank models of antisymmetric fermions.

hep-th

On BRST Lagrangian formulation for massive higher-spin fields in $4D$ Minkowski space

We give a brief overview of the BRST approach to the gauge invariant Lagrangian formulation for free massive higher-spin bosonic fields focusing on two specific aspects. First, the theory is considered in four dimensional flat space in terms of spin-tensor fields with two component undotted and dotted indices. This leads to a significant simplification of the whole approach in comparison with the one where the fields with vector indices were used, since now there is no need to introduce a constraint responsible for the traces of the fields into the BRST charge. Second, we develop an extremely simple and clear procedure to eliminate all the auxiliary fields and prove that the BRST equations of motion identically reproduce the basic conditions for irreducible representations of the Poincáre group with a given mass and spin. Similar to the massless theory, the final Lagrangian for massive higher-spin fields is formulated in triplet form. The BRST formulation leads to a system of fields that are clearly subdivided into the basic spin $s$ field, Zinoviev-like auxiliary fields, Singh-Hagen-like auxiliary fields, and special BRST auxiliary fields. The auxiliary fields can be partially eliminated by gauge fixing and/or using the equations of motion. This allows one to obtain formally different (with different numbers of auxiliary fields) but equivalent Lagrangian formulations.

hep-th

The structure of divergences in the higher-derivative supersymmetric $6D$ gauge theory

Using the harmonic superspace approach, we perform a comprehensive study of the structure of divergences in the higher-derivative $6D$, ${\cal N}=(1,0)$ supersymmetric Yang--Mills theory coupled to the hypermultiplet in the adjoint representation. The effective action is constructed in the framework of the superfield background field method with the help of ${\cal N}=(1,0)$ supersymmetric higher-derivative regularization scheme which preserves all symmetries of the theory. The one-loop divergences are calculated in a manifestly gauge invariant and $6D$, ${\cal N}=(1,0)$ supersymmetric form hopefully admitting a generalization to higher loops. The $β$-function in the one-loop approximation is found and analyzed. In particular, it is shown that the one-loop $β$-function for an arbitrary regulator function is specified by integrals of double total derivatives in momentum space, like it happens in $4D,\, {\cal N}=1$ superfield gauge theories. This points to the potential possibility to derive the all-loop NSVZ-like exact $β$-function in the considered theory.

hep-th

Three-loop chiral effective potential in the Wess-Zumino model

We calculate the three-loop contribution to the chiral effective potential in the massless Wess-Zumino model. It is shown that while the non-renormalisation theorem forbids divergent contributions to the chiral potential, in the massless case the finite corrections survive. There are only three three-loop supergraphs that give rise to a superfield effective action in the pure chiral sector. Two of them are UV finite while the third requires one-loop counterterm corresponding to the chiral field renormalisation.

hep-th

General Lagrangian Formulation for Higher Spin Fields with Arbitrary Index Symmetry. I. Bosonic fields

We construct a Lagrangian description of irreducible integer higher-spin representations of the Poincare group with an arbitrary Young tableaux having k rows, on a basis of the universal BRST approach. Starting with a description of bosonic mixed-symmetry higher-spin fields in a flat space of any dimension in terms of an auxiliary Fock space associated with special Poincare module, we realize a conversion of the initial operator constraint system (constructed with respect to the relations extracting irreducible Poincare-group representations) into a first-class constraint system. For this purpose, we find, for the first time, auxiliary representations of the constraint subalgebra, to be isomorphic due to Howe duality to sp(2k) algebra, and containing the subsystem of second-class constraints in terms of new oscillator variables. We propose a universal procedure of constructing unconstrained gauge-invariant Lagrangians with reducible gauge symmetries describing the dynamics of both massless and massive bosonic fields of any spin. It is shown that the space of BRST cohomologies with a vanishing ghost number is determined only by the constraints corresponding to an irreducible Poincare-group representation. As examples of the general procedure, we formulate the method of Lagrangian construction for bosonic fields subject to arbitrary Young tableaux having 3 rows and derive the gauge-invariant Lagrangian for new model of massless rank-4 tensor field with spin $(2,1,1)$ and second-stage reducible gauge symmetries.

hep-th

On the realization of infinite (continuous) spin field representations in AdS${}_{\mathbf{4}}$ space

We study the symmetry properties of infinite spin fields in $\rm{AdS}_4$ space which are involved in the Lagrangian model proposed in arXiv:2403.14446 where the main role is played by operator constraints. It is shown that the conditions defining infinite spin states in $\rm{AdS}_4$ space are $\mathrm{SO}(2,3)$-invariant. It is found that in the model under consideration the Casimir operators are completely fixed by the constraint operators and only one of the Casimir operators is independent. It is shown that in this model, infinite spin fields in $\rm{AdS}_4$ space are described by the most degenerate representations of the $\mathrm{SO}(2,3)$ group.

hep-th

On BRST Lagrangian formulation of massless higher spin fields

The paper is dedicated to the blessed memory of Professor Vladislav Gavrilovich Bagrov, an outstanding Russian scientist in the area of theoretical and mathematical physics. He had a great influence on the formation of the scientific interests dozens of scientists in Tomsk and Russia as a whole. Two of the authors of this paper (I.L.B and V.A.K) are to one degree or another grateful to Professor V.G. Bagrov for comprehensive support in the initial period of their scientific career. Two other authors (S.A.F. and A.P.I.) are familiar with and use the work of scientists from the Tomsk School of Theoretical Physics, founded by Professor V.G. Bagrov. The paper is devoted to certain aspects of the higher-spin field theory, which were mainly initiated and continued during of I.L.B and V.A.K work in Tomsk. We demonstrate in details the simplicity and clearity of the Lagrangian formulation for free four-dimensional massless higher-spin fields within the universal BRST approach, while describing these fields in terms of two-component spin-tensors.

hep-th

BRST construction for infinite spin field on $AdS_4$

We generalize the first class constraints that describe the infinite spin irreducible $4D$ Poincaré group representation in flat space to new first class constraints in $AdS_4$ space. The constraints are realized as operators acting in Fock space spanned by the creation and annihilation operators with two-component spinor indices. As a result, we obtain a new closed gauge algebra on $AdS_4$ with the known flat space limit. Using this gauge algebra, we construct the BRST charge and derive the Lagrangian and gauge transformations for free bosonic infinite spin field theory in $AdS_4$ space.

hep-th