96,865 research outputs found
Supersymmetry without Supersymmetry
We present four-dimensional M-theory vacua with N>0 supersymmetry which, from
the perspective of perturbative Type IIA string theory, have N=0. Such vacua
can appear when the compactifying 7-manifold is a U(1) fibration. The missing
superpartners are Dirichlet 0-branes. Someone unable to detect Ramond-Ramond
charge would thus conclude that these worlds have no unbroken supersymmetry. In
particular, the gravitinos (and also some of the gauge bosons) are 0-branes not
seen in perturbation theory but which curiously remain massless however weak
the string coupling.Comment: Latex, 16 pages. Minor revisions and reference adde
Mechanisms of Supersymmetry Breaking in the MSSM
Preliminary Remarks. Gauge mediated supersymmetry breaking. Gravity mediated
supersymmetry breaking. Anomaly mediated supersymmetry breaking. Gaugino
mediated supersymmetry breaking. Braneworld supersymmetry breaking.
Conclusions.Comment: New references added, minor misprints corrected, text otherwise
unchange
Summary of the SUSY Working Group of the 1999 Les Houches Workshop
The results obtained by the Working Group on Supersymmetry at the 1999 Les
Houches Workshop on Collider Physics are summarized. Separate chapters treat
"general" supersymmetry, R-parity violation, gauge mediated supersymmetry
breaking, and anomaly mediated supersymmetry breaking.Comment: LaTeX, 110 pages with numerous .ps and .eps files. proc.tex is main
tex fil
Nonlinear Pseudo-Supersymmetry in the Framework of N-fold Supersymmetry
We recall the importance of recognizing the different mathematical nature of
various concepts relating to PT-symmetric quantum theories. After clarifying
the relation between supersymmetry and pseudo-supersymmetry, we prove
generically that nonlinear pseudo-supersymmetry, recently proposed by Sinha and
Roy, is just a special case of N-fold supersymmetry. In particular, we show
that all the models constructed by these authors have type A 2-fold
supersymmetry. Furthermore, we prove that an arbitrary one-body quantum
Hamiltonian which admits two (local) solutions in closed form belongs to type A
2-fold supersymmetry, irrespective of whether or not it is Hermitian,
PT-symmetric, pseudo-Hermitian, and so on.Comment: 10 pages, no figures; typos correcte
Extended supersymmetry and its reduction on a circle with point singularities
We investigate -extended supersymmetry in one-dimensional quantum
mechanics on a circle with point singularities. For any integer ,
supercharges are explicitly constructed in terms of discrete transformations,
and a class of singularities compatible with supersymmetry is clarified. In our
formulation, the supersymmetry can be reduced to -extended supersymmetry for
any integer . The degeneracy of the spectrum and spontaneous supersymmetry
breaking are also studied.Comment: 36 pages, 5 figures, 2 table
Sigma models with off-shell N=(4,4) supersymmetry and noncommuting complex structures
We describe the conditions for extra supersymmetry in N=(2,2) supersymmetric
nonlinear sigma models written in terms of semichiral superfields. We find that
some of these models have additional off-shell supersymmetry. The (4,4)
supersymmetry introduces geometrical structures on the target-space which are
conveniently described in terms of Yano f-structures and Magri-Morosi
concomitants. On-shell, we relate the new structures to the known
bi-hypercomplex structures.Comment: 20 pages; v2: significant corrections, clarifications, and
reorganization; v3: discussion of supersymmetry vs twisted supersymmetry
added, relevant signs corrected
Open-string models with broken supersymmetry
I review the salient features of three classes of open-string models with
broken supersymmetry. These suffice to exhibit, in relatively simple settings,
the two phenomena of ``brane supersymmetry'' and ``brane supersymmetry
breaking''. In the first class of models, to lowest order supersymmetry is
broken both in the closed and in the open sectors. In the second class of
models, to lowest order supersymmetry is broken in the closed sector, but is
{\it exact} in the open sector, at least for the low-lying modes, and often for
entire towers of string excitations. Finally, in the third class of models, to
lowest order supersymmetry is {\it exact} in the closed (bulk) sector, but is
broken in the open sector. Brane supersymmetry breaking provides a natural
solution to some old difficulties met in the construction of open-string vacua.Comment: 18 pages, LATEX. Minor corrections. Contributed also to Como 2001
"Statistical Field Theory", Les Houches 2001 "Gravity, gauge theories and
strings", Johns Hopkins Workshop 200
The Holographic Supercurrent Anomaly
The \gamma-trace anomaly of supersymmetry current in a supersymmetric gauge
theory shares a superconformal anomaly multiplet with the chiral R-symmetry
anomaly and the Weyl anomaly, and its holographic reproduction is a valuable
test to the AdS/CFT correspondence conjecture. We investigate how the
\gamma-trace anomaly of the supersymmetry current of {\cal N}=1
four-dimensional supersymmetric gauge theory in an {\cal N}=1 conformal
supergravity background can be extracted out from the gauged
supergravity in five dimensions. It is shown that the reproduction of this
super-Weyl anomaly originates from the following two facts: First the {\cal
N}=2 bulk supersymmetry transformation converts into {\cal N}=1 superconformal
transformation on the boundary, which consists of {\cal N}=1 supersymmetry
transformation and special conformal supersymmetry (or super-Weyl)
transformation; second the supersymmetry variation of the bulk action of
five-dimensional gauged supergravity is a total derivative. The
non-compatibility of supersymmetry and the super-Weyl transformation invariance
yields the holographic supersymmetry current anomaly. Furthermore, we speculate
on that the contribution from the external gauge and gravitational background
fields to the superconformal anomaly may have different holographic origin.Comment: 22 pages, RevTex; more correction
A Solution to the Problem in Gauge-mediated Supersymmetry-breaking Models
We point out that a sector required to set the cosmological constant to zero
in gauge-mediated supersymmetry-breaking models naturally produces a
supersymmetry-invariant mass ( term) for Higgs doublets of the order of
the electroweak scale. Since this new sector preserves the supersymmetry, it
does not generate supersymmetry-breaking masses for the Higgs doublets and thus
the problem is solved.Comment: Latex fil
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