7,589 research outputs found
Duality and Canonical Transformations
We present a brief review on the canonical transformation description of some
duality symmetries in string and gauge theories. In particular, we consider
abelian and non-abelian T-dualities in closed and open string theories as well
as S-duality in abelian and non-abelian non-supersymmetric gauge theories.Comment: 21 pgs, latex file, talk given at the Argonne Duality Institute, June
27-July 12, 1996, to appear in the e-proceeding
Non-BPS D-brane Solutions in Six Dimensional Orbifolds
Starting with the non-BPS D0-brane solution of IIB/ constructed recently by Eyras and Panda we construct via T-duality the non-BPS D2-brane and D1-brane solutions of IIB/ and IIA/ predicted by Sen. The D2-brane couples magnetically to the vector field of the NS5B-brane living in the twisted sector of the Type IIB orbifold, whereas the D1-brane couples (electrically and magnetically) to the self-dual 2-form potential of the NS5A-brane that is present in the twisted sector of the Type IIA orbifold construction. Finally we discuss the eleven dimensional interpretation of these branes as originating from a non-BPS M1-brane solution of M-theory orientifolded by
Some Global Aspects of Duality is String Theory
We explore some of the global aspects of duality transformations in String
Theory and Field Theory. We analyze in some detail the equivalence of dual
models corresponding to different topologies at the level of the partition
function and in terms of the operator correspondence for abelian duality. We
analyze the behavior of the cosmological constant under these transformations.
We also explore several examples of non-abelian duality where the classical
background interpretation can be maintained for the original and the dual
theories. In particular we construct a non-abelian dual of which
turns out to be a three-dimensional black holeComment: 31pp. One figure available upon request. CERN-TH-6991/6
Power scaling rules for charmonia production and HQEFT
We discuss the power scaling rules along the lines of a complete Heavy Quark
Effective Field Theory (HQEFT) for the description of heavy quarkonium
production through a color-octet mechanism. To this end, we firstly derive a
tree-level heavy quark effective Lagrangian keeping both particle-antiparticle
mixed sectors allowing for heavy quark-antiquark pair annihilation and
creation, but describing only low-energy modes around the heavy quark mass.
Then we show the consistency of using HQEFT fields in constructing four-fermion
local operators a la NRQCD, to be identified with standard color-octet matrix
elements. We analyze some numerical values extracted from charmonia production
by different authors and their hierarchy in the light of HQEFT.Comment: LaTeX, 19 pages, 3 EPS figure
Duality of Super D-brane Actions in General Type IIB Supergravity Background
We examine duality transformations of supersymmetric and -symmetric
Dp-brane actions in a general type II supergravity background where in
particular the dilaton and the axion are supposed to not be zero or a constant
but a general superfield. Due to non-constant dilaton and axion, we can
explicitly show that the dilaton and the axion as well as the two 2-form gauge
potentials transform as doublets under the transformation from the
point of view of the world-volume field theory.Comment: 32 pages, LaTex 2
CP violation in semileptonic tau lepton decays
The leading order contribution to the direct CP asymmetry in tau^{+/-} ->
K^{+/-} pi^0 nu_{tau} decay rates is evaluated within the Standard Model. The
weak phase required for CP violation is introduced through an interesting
mechanism involving second order weak interactions, which is also responsible
for tiny violations of the Delta S= Delta Q rule in K_{l3} decays. The
calculated CP asymmetry turns out to be of order 10^{-12}, leaving a large
window for studying effects of non-standard sources of CP violation in this
observable.Comment: 5 pages, 3 figures, version published in Phys.Rev.
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