425 research outputs found
Low Energy Processes Associated with Spontaneously Broken N=2 Supersymmetry
We consider low energy processes described by the N=2 supercurrent on its
partially (to N=1) and spontaneously broken vacuum and the attendant
Nambu-Goldstone fermion (NGF), which the presence of the electric and magnetic
Fayet-Iliopoulos (FI) terms is responsible for. We show suppressions of
amplitudes decaying into the NGF as its momentum becomes small. In the
lagrangian realization (namely, the model of arXiv:hep-th/0409060) of the
conserved supercurrent, the NGF resides in the overall U(1), which is
nonetheless not decoupled, and interacts with the SU(N) sector through
nonderivative as well as derivative couplings. The low energy suppression is
instead accomplished by a cancellation between the annihilation diagram from
the Yukawa couplings and the contact four-Fermi terms. We give a complete form
of the supercurrent and the model is recast in more transparent notation.Comment: 20 pages, 6 figure
Introducing Dynamical Triangulations to the Type IIB Superstrings
In order to consider non-perturbative effects of superstrings, we try to
apply dynamical triangulations to the type IIB superstrings. The discretized
action is constructed from the type IIB matrix model proposed as a constructive
definition of superstring theory. The action has the local N=2 supersymmetry
explicitly, and has no extra fermionic degrees of freedom. We evaluate the
partition function for some simple configurations and discuss constraints
required from the finiteness of partition functions.Comment: LATTICE99, 3 pages, LaTeX with 2 figures, espcrc2.st
Normalization of Off-shell Boundary State, g-function and Zeta Function Regularization
We consider the model in two dimensions with boundary quadratic deformation
(BQD), which has been discussed in tachyon condensation. The partition function
of this model (BQD) on a cylinder is determined, using the method of zeta
function regularization. We show that, for closed channel partition function, a
subtraction procedure must be introduced in order to reproduce the correct
results at conformal points. The boundary entropy (g-function) is determined
from the partition function and the off-shell boundary state. We propose and
consider a supersymmetric generalization of BQD model, which includes a
boundary fermion mass term, and check the validity of the subtraction
procedure.Comment: 21 pages, LaTeX, comments and 3 new references adde
Instanton Correction of Prepotential in Ruijsenaars Model Associated with N=2 SU(2) Seiberg-Witten Theory
Instanton correction of prepotential of one-dimensional SL(2) Ruijsenaars
model is presented with the help of Picard-Fuchs equation of Pakuliak-Perelomov
type. It is shown that the instanton induced prepotential reduces to that of
the SU(2) gauge theory coupled with a massive adjoint hypermultiplet.Comment: revtex, 15 pages, to be published in Journal of Mathematical Physic
Affine Lie Algebras in Massive Field Theory and Form-Factors from Vertex Operators
We present a new application of affine Lie algebras to massive quantum field
theory in 2 dimensions, by investigating the limit of the q-deformed
affine symmetry of the sine-Gordon theory, this limit occurring
at the free fermion point. Working in radial quantization leads to a
quasi-chiral factorization of the space of fields. The conserved charges which
generate the affine Lie algebra split into two independent affine algebras on
this factorized space, each with level 1 in the anti-periodic sector, and level
in the periodic sector. The space of fields in the anti-periodic sector can
be organized using level- highest weight representations, if one supplements
the \slh algebra with the usual local integrals of motion. Introducing a
particle-field duality leads to a new way of computing form-factors in radial
quantization. Using the integrals of motion, a momentum space bosonization
involving vertex operators is formulated. Form-factors are computed as vacuum
expectation values in momentum space. (Based on talks given at the Berkeley
Strings 93 conference, May 1993, and the III International Conference on
Mathematical Physics, String Theory, and Quantum Gravity, Alushta, Ukraine,
June 1993.)Comment: 13 pages, CLNS 93/125
Progress in QCD next-to-leading order calculations
I review progress related to the calculation of QCD jet cross sections at the
NLO accuracy. After a short introduction into the theory of NLO calculations, I
discuss two recent developments: the calculation of two- and three-jet
leptoproduction at the NLO accuracy and the extension of the dipole subtraction
method for computing NLO corrections for processes involving massive partons.Comment: 5 pages, 4 figures, LaTeX using JHEP3.cls, Invited talk at the
International Europhysics Conference on High-Energy Physics (HEP 2001
The matrix model version of AGT conjecture and CIV-DV prepotential
Recently exact formulas were provided for partition function of conformal
(multi-Penner) beta-ensemble in the Dijkgraaf-Vafa phase, which, if interpreted
as Dotsenko-Fateev correlator of screenings and analytically continued in the
number of screening insertions, represents generic Virasoro conformal blocks.
Actually these formulas describe the lowest terms of the q_a-expansion, where
q_a parameterize the shape of the Penner potential, and are exact in the
filling numbers N_a. At the same time, the older theory of CIV-DV prepotential,
straightforwardly extended to arbitrary beta and to non-polynomial potentials,
provides an alternative expansion: in powers of N_a and exact in q_a. We check
that the two expansions coincide in the overlapping region, i.e. for the lowest
terms of expansions in both q_a and N_a. This coincidence is somewhat
non-trivial, since the two methods use different integration contours:
integrals in one case are of the B-function (Euler-Selberg) type, while in the
other case they are Gaussian integrals.Comment: 27 pages, 1 figur
Constant mean curvature surfaces in AdS_3
We construct constant mean curvature surfaces of the general finite-gap type
in AdS_3. The special case with zero mean curvature gives minimal surfaces
relevant for the study of Wilson loops and gluon scattering amplitudes in N=4
super Yang-Mills. We also analyze properties of the finite-gap solutions
including asymptotic behavior and the degenerate (soliton) limit, and discuss
possible solutions with null boundaries.Comment: 19 pages, v2: minor corrections, to appear in JHE
On the property of Cachazo-Intriligator-Vafa prepotential at the extremum of the superpotential
We consider CIV-DV prepotential F for N=1 SU(n) SYM theory at the extremum of
the effective superpotential and prove the relation Comment: LaTeX, 10 pages; v2: some misprints corrected; v3: submitted to
Phys.Rev.
Special colored Superpolynomials and their representation-dependence
We introduce the notion of "special superpolynomials" by putting q=1 in the
formulas for reduced superpolynomials. In this way we obtain a generalization
of special HOMFLY polynomials depending on one extra parameter t. Special
HOMFLY are known to depend on representation R in especially simple way: as
|R|-th power of the fundamental ones. We show that the same dependence persists
for our special superpolynomials in the case of symmetric representations, at
least for the 2-strand torus and figure-eight knots. For antisymmetric
representations the same is true, but for t=1 and arbitrary q. It would be
interesting to find an interpolation between these two relations for arbitrary
representations, but no superpolynomails are yet available in this case.Comment: 5 page
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