188 research outputs found
The SUSY World
Summary Talk of the Workshop `Properties of SUSY particles' Erice, September
28 -- October 4, 1992.Comment: 23 pages, 6 figures (not included), CERN-TH.6951/93, LATEX using
worldsci.sty macro, hardcopy with figures can be sent via air-mail upon
reques
Quantum corrections to broken N=8 supergravity
The discovery of the Higgs boson and the non-discovery (so far) of additional
particles at the TeV scale underline our poor understanding of the hierarchy
problems in the physics of the fundamental interactions. Loosely motivated by
this consideration, I review some recent results on the classical and quantum
stability of Minkowski vacua in spontaneously broken N=8 supergravity.Comment: 6 pages: contribution to the proceedings of ICHEP2012, The 36th
International Conference on High Energy Physics, 4-11 July 2012, Melbourne,
Australi
Theory Summary
Talk given at the XLVIII Rencontres de Moriond, Electroweak Interactions and
Unified Theories, La Thuile, Italy, 2-9 March 2013, to appear in the
Proceedings.Comment: 16 pages, 7 figure
Supersymmetry and gauge symmetry breaking with naturally vanishing vacuum energy
We review the construction of supergravity models where the Higgs and
super-Higgs effects are simultaneously realized, with naturally vanishing
classical vacuum energy and goldstino components along gauge-non-singlet
directions: this situation is likely to occur in the effective theories of
realistic string models. (Invited talk presented at SUSY--95, Palaiseau,
France, 15--19 May 1995)Comment: plain LATEX, no figures, 11 page
Geometrical hierarchies in classical supergravity
We introduce a supergravity model with a very simple hidden sector
coupled to the electroweak gauge and Higgs sectors of the MSSM. At the
classical level, supersymmetry and are both spontaneously
broken, with vanishing vacuum energy. Two real flat directions control the two
symmetry-breaking scales and . The two massless scalars are a
gauge singlet and the standard Higgs boson. All other unobserved particles have
masses of order . This may be a new starting point for studying the
compatibility of naturalness with the observed mass hierarchies.Comment: 5 pages, no figure
Quantum corrections to broken N = 8 supergravity
We show that the one-loop effective potential of spontaneously broken N=8
supergravity is calculable and finite at all classical four-dimensional
Minkowski vacua without tachyons in the spectrum. The reason is that the
supertraces of the quadratic and quartic mass matrices vanish along the
classically flat directions: Str M^2 = Str M^4 =0. We also show that Str M^6 =
0 but Str M^8 > 0 in a broad class of vacua with broken supersymmetry on a flat
background, which includes all those explicitly identified so far. We find
analytical and numerical evidence that the corresponding one-loop effective
potential is negative-definite.Comment: 30 pages. v2: few misprints corrected. v3: JHEP published versio
A new class of N=1 no-scale supergravity models
We introduce a new N=1 no-scale supergravity model with F- and D-term
breaking. It contains a single chiral supermultiplet T and a single U(1) vector
multiplet U, gauging an axionic shift symmetry. Both supersymmetry and the
gauge symmetry are spontaneously broken, with the spin-3/2, spin-1 and spin-1/2
masses sliding along a classical flat direction, with a single real massless
scalar in the spectrum. The other degrees of freedom are absorbed by the
massive gravitino and vector. We extend our model, under very mild conditions,
to general gauge groups and matter content.Comment: 4 pages, RevTeX. Version to be published in PR
On sgoldstino-less supergravity models of inflation
We go a step further in the search for a consistent and realistic
supergravity model of large-field inflation by building a class of models with
the following features: during slow-roll, all the scalar fields other than the
inflaton are frozen by large inflaton-dependent masses or removed from the
spectrum; at the end of inflation, supersymmetry is spontaneously broken with
naturally vanishing classical vacuum energy. We achieve this by combining some
geometrical properties of the Kaehler potential with the consistent use of a
single nilpotent chiral superfield, in one-to-one correspondence with the
supersymmetry-breaking direction in field space at the vacuum.Comment: 19 pages. v2: references added and few minor changes to the text. v3:
published versio
Beyond Twisted Tori
Exploiting the fact that Kaluza-Klein monopoles and the associated
generalized orbifold planes are sources for geometrical fluxes, omega, we show
that the standard constraint omega.omega=0, valid for superstring
compactifications on twisted tori, can be consistently relaxed. This leads to
novel possibilities for constructing superstring models with fluxes and
localized sources, as well as for stabilizing moduli. This also explains the
ten-dimensional origin of a family of N=4 gauged supergravities, whose
interpretation in type-IIA orientifold compactifications was lacking.Comment: 12 page
Higgs Boson Properties in the Standard Model and its Supersymmetric Extensions
We review the realization of the Brout-Englert-Higgs mechanism in the
electroweak theory and describe the experimental and theoretical constraints on
the mass of the single Higgs boson expected in the minimal Standard Model. We
also discuss the couplings of this Higgs boson and its possible decay modes as
functions of its unknown mass. We then review the structure of the Higgs sector
in the minimal supersymmetric extension of the Standard Model (MSSM), noting
the importance of loop corrections to the masses of its five physical Higgs
bosons. Finally, we discuss some non-minimal models.Comment: To be published in "Search of the Higgs Particle", Comptes Rendus de
l'Academie des Sciences, Franc
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