6,619 research outputs found
LHC/ILC Interplay in SUSY Searches
Combined analyses at the Large Hadron Collider and at the International
Linear Collider are important to reveal precisely the new physics model as, for
instance, supersymmetry. Examples are presented where ILC results as input for
LHC analyses could be crucial for the identification of signals as well as of
the underlying model. The synergy of both colliders leads also to rather
accurate SUSY parameter determination and powerful mass constraints even if the
scalar particles have masses in the multi-TeV range.Comment: 5 pages, contribution to the proceedings of EPS0
The Challenge of Determining SUSY Parameters in Focus-Point-Inspired Cases
We discuss the potential of combined LHC and ILC experiments for SUSY
searches in a difficult region of the parameter space, in which all sfermion
masses are above the TeV scale. Precision analyses of cross sections of light
chargino production and forward--backward asymmetries of decay leptons and
hadrons at the ILC, together with mass information on \tilde{\chi}^0_2 and
squarks from the LHC, allow us to fit rather precisely the underlying
fundamental gaugino/higgsino MSSM parameters and to constrain the masses of the
heavy virtual sparticles. For such analyses the complete spin correlations
between the production and decay processes have to be taken into account. We
also took into account expected experimental uncertainties.Comment: 4 pages, talk given at XLI Rencontres de Moriond on Electroweak
Interactions and Unified Theories, La Thuile, Italy, 11-18 Mar 200
The lightest neutralino in the MNSSM
We examine the allowed mass range of the lightest neutralino within the
Minimal Non--minimal Supersymmetric Standard Model. Being absolutely stable if
R-parity is conserved this lightest neutralino is a candidate for the dark
matter of the universe. We establish the theoretical upper bound on the
lightest neutralino mass and obtain an approximate solution for this mass.Comment: Submitted for the SUSY07 proceedings, 4 pages, LaTeX, 3 eps figures,
some minor changes to the tex
Gravitational and magnetosonic waves in gamma-ray bursts
One of the possible sources of gamma-ray bursts are merging, compact
neutronstar binaries. More than 90% of the binding energy of such a binary is
released in the form of gravitational waves (GWs) in the last few seconds of
the spiral-in phase before the formation of a black hole. In this article we
investigate whether a fraction of this GW-energy is transferred to
magnetohydrodynamic waves in the magnetized plasma wind around the binary.
Using the 3+1 orthonormal tedrad formalism, we study the propagation of a
monochromatic, plane fronted, linearly polarized GW perpendicular to the
ambient magnetic field in an ultra-relativistic wind, first in the comoving and
then in the observer frame. A closed set of general relativistic
magnetohydrodynamic equations is derived in the form of conservation laws for
electric charge, matter energy, momentum and magnetic energy densities. We
linearize these equations under the action of a monochromatic GW, which acts as
a driver and find that fast magneto-acoustic waves grow, with amplitudes
proportional to the GW amplitude and frequency and the strength of the
background magnetic field.Comment: Accepted for publication in Astronomy & Astrophysics (A&A). 7 pages,
1 figur
Neutralino Pair Production and 3-Body Decays at Linear Colliders as Probes of CP Violation in the Neutralino System
In the CP-invariant supersymmetric theories, the steep S-wave (slow P-wave)
rise of the cross section for any non-diagonal neutralino pair production in
annihilation, (), near threshold is accompanied by the slow P-wave (steep S-wave) decrease
of the fermion invariant mass distribution of the 3-body neutralino decay,
( or ), near the end
point. These selection rules, unique to the neutralino system due to its
Majorana nature, guarantee that the observation of simultaneous sharp S-wave
excitations of the production cross section near threshold and the lepton and
quark invariant mass distribution near the end point is a qualitative,
unambiguous evidence for CP violation in the neutralino system.Comment: 11 pages, 1 eps figure, a reference adde
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