263 research outputs found
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.Comment: 32 pages; v4: Published versio
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.Comment: 12 pages, minor correction
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.Comment: 15 pages; v2: minor correction
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.Comment: 15 pages, 3 figures, 2 references added, minor corrections, accepted
for publication in Physics Letters
"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.Comment: 13 pages. v2: minor misprints corrected; v3: note added about missed
terms in the actio
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