38 research outputs found
Radiative Contributions to TGC in the MSSM
We give a brief account of recent calculations of radiative contributions to
the Triple Gauge Couplings (TGC) from the Minimal Supersymmetric Standard Model
(MSSM), at a 500 GeV collider. Our results indicate that, although
these MSSM virtual contributions indeed are of the order of the expected
accuracy on TGC measurements, the generally neglected box contributions to TGC
also are likely to be relevant at such high energies.Comment: 4 pages, Latex, 2 Postscript figures, tar'ed uuencoded files, To
appear in the Proceedings of the Physics with Linear Colliders
Workshop, Annecy--Gran Sasso--Hamburg 1995, ed. P. Zerwa
Determining fundamental parameters from the chargino sector in Left-Right Supersymmetric models
Analytical expressions relating the fundamental parameters describing the
chargino sector in the context of the Left-Right Supersymmetric model are
constructed. A general complex extension of the real non-symmetric chargino
mass matrix including all possible CP-violating phases is considered. The
method used for such a effects is the projector formalism based on the explicit
knowledge of two unitary matrices diagonalizing the chargino mass matrix. Some
possible scenarios allowing us to extract analytical and numerical values for
the unknown parameters are considered. Moreover, an algorithm allowing us to
disentangle the fundamental parameters of the chargino sector, based on
possible measurements of some class of cross-section observables related to the
chargino pair production in annihilation processes, is described.
Some comparisons with the corresponding results in the context of the Minimal
Supersymmetric Standard Model are given.Comment: 48 pages, 13 figure
Complementarity of Gamma-ray and LHC Searches for Neutralino Dark Matter in the Focus Point Region
We study the complementarity between the indirect detection of dark matter
with gamma-rays in H.E.S.S. and the supersymmetry searches with ATLAS at the
Large Hadron Collider in the Focus Point region within the mSUGRA framework.
The sensitivity of the central telescope of the H.E.S.S. II experiment with an
energy threshold of ~ 20 GeV is investigated. We show that the detection of
gamma-ray fluxes of O(10^-12) cm-2s-1 with H.E.S.S. II covers a substantial
part of the Focus Point region which may be more difficult for LHC experiments.
Despite the presence of multi-TeV scalars, we show that LHC will be sensitive
to a complementary part of this region through three body NLSP leptonic decays.
This interesting complementarity between H.E.S.S. II and LHC searches is
further highlighted in terms of the gluino mass and the two lightest neutralino
mass difference.Comment: 11 pages, 6 figures, accepted for publication in Phys. Rev. D on
February 7, 2008 (slight modifications: references updated and text improved
Gravitino dark matter in brane-world cosmology
The gravitino dark matter hypothesis in the brane cosmology is studied. The
theoretical framework is the CMSSM for particle physics and RS II brane model
for gravity. It is found that the gravitino can play the role of dark matter in
the universe and we determine what the gravitino mass should be for different
values of the five-dimensional Planck mass. An upper bound is obtained for the
latter.Comment: Improved version with minor corrections, to appear in JCA
Inverting the Supersymmetric Standard Model Spectrum: from Physical to Lagrangian Ino Parameters
We examine the possibility of recovering the supersymmetric (and soft
supersymmetry breaking) Lagrangian parameters as direct {\em analytical}
expressions of appropriate physical masses, for the unconstrained (but CP and
R-parity conserving) minimal supersymmetric standard model. We concentrate
mainly on the algebraically non-trivial "inversion" for the ino parameters, and
obtain, for given values of , simple analytical expressions for the
, and parameters in terms of three arbitrary input physical
masses, namely either two chargino and one neutralino masses, or alternatively
one chargino and two neutralino masses. We illustrate and discuss in detail the
possible occurrence of ambiguities in this reconstruction. The dependence of
the resulting ino Lagrangian parameters upon physical masses is illustrated,
and some simple generic behaviour uncovered in this way. We finally briefly
sketch generalizing such an inversion to the full set of MSSM Lagrangian
parameters.Comment: Latex, 28 pages, 6 figures, 1 table, some typos corrected, one
paragraph extended in section 4.2. Version to appear in Phys. Rev.
Phases in the gaugino sector: direct reconstruction of the basic parameters and impact on the neutralino pair production
We consider recovering analytically the (generally complex) parameters ,
and of the gaugino and Higgsino Lagrangian, from appropriate
physical input in the chargino and neutralino sectors. For given ,
we obtain very simple analytic solutions for , , in the
chargino sector and a twofold , analytic solution in the
neutralino sector, assuming two chargino, two neutralino masses, and one of the
chargino mixing angles as physical input. The twofold ambiguity in the
neutralino parameters reconstruction may be essentially resolved by measuring
the production cross-section at future linear
collider energies, which we study explicitly with the phase dependences. Some
salient features and specific properties of this complex case gaugino "spectrum
inversion" are illustrated and compared with the similar inversion in the real
case. In particular, our algorithms exhibit in a direct and transparent way the
non-trivial theoretical correlation among the chargino and neutralino
parameters, and the resulting allowed domains when only a subset of the
required physical input masses and production cross-sections is known.Comment: Latex, 28 pages, 10 figure
The Minimal Supersymmetric Standard Model: Group Summary Report
CONTENTS: 1. Synopsis, 2. The MSSM Spectrum, 3. The Physical Parameters, 4.
Higgs Boson Production and Decays, 5. SUSY Particle Production and Decays, 6.
Experimental Bounds on SUSY Particle Masses, 7. References.Comment: 121 pages, latex + epsfig, graphicx, axodraw, Report of the MSSM
working group for the Workshop "GDR-Supersym\'etrie",France. Rep. PM/98-4
Higgs Boson Production in Association with Scalar Top Quarks at Proton Colliders
We investigate the production of Higgs particles in association with the
supersymmetric scalar partners of the top quark at proton colliders. In the
minimal supersymmetric extension of the Standard Model, the cross sections for
the production of the lightest neutral Higgs boson in association with top
squark pairs can be rather large, substantially exceeding the rate for the
associated Higgs boson production with top quarks. If the lightest top squark
is not much heavier than the top quark, this process will enhance the potential
of the CERN Large Hadron Collider to discover the lightest neutral Higgs boson,
and will open a window to the study of the Higgs-stop coupling, the potentially
largest electroweak coupling in the supersymmetric theory.Comment: 9 pages, LaTex, 3 PostScript figures using epsfig.st