1,407 research outputs found
Degradation of AB25 dye in liquid medium by atmospheric pressure non-thermal plasma and plasma combination with photocatalyst TiO2
In this work, degradation of the anthraquinonic dye Acid Blue 25 by non-thermal plasma at atmospheric pressure with and without photocatalyst is investigated. Titanium dioxide (TiO2) is used as a photocatalyst. The dye degradation by plasma in the presence of TiO2 is investigated as a function of TiO2 concentration, dye concentration and pH. The degradation rate is higher in acidic solutions with pH of 2 to 4.3, especially at pH 2, and decreases to 0.38 mg L-1 min(-1) with the increase of pH from 2 to 5.65. A similar effect is observed in basic media, where a higher degradation rate is found at pH = 10.3. The degradation rate increases in the presence of TiO2 compared to the discharge without photocatalysis. The results show that the degradation of the dye increases in the presence of TiO2 until the catalyst load reaches 0.5 g L-1 after which the suppression of AB25 degradation is observed. The results indicate that the tested advanced oxidation processes are very effective for the degradation of AB25 in aqueous solutions
Diffractive SUSY particle production at the LHC
We give detailed predictions for diffractive SUSY Higgs boson and top squark
associated productions at the LHC via the exclusive double pomeron exchange
mechanism. We study how the SUSY Higgs cross section and the signal over
background ratio are enhanced as a function of tangent beta in different
regimes. The prospects are particularly promising in the ``anti-decoupling''
regime, which we study in detail. We also give the prospects for a precise
measurement of the top squark mass using the threshold scan of central
diffractive associated top squark events at the LHC.Comment: 14 pages, 6 fig
Radiative Neutralino Decay in Supersymmetric Models
The radiative decay Z2-> Z1 gamma proceeds at the one-loop level in the MSSM.
It can be the dominant decay mode for the second lightest neutralino Z2 in
certain regions of parameter space of supersymmetric models, where either a
dynamical and/or kinematic enhancement of the branching fraction occurs. We
perform an updated numerical study of this decay mode in both the minimal
supergravity model (mSUGRA) and in the more general MSSM framework. In mSUGRA,
the largest rates are found in the ``focus point'' region, where the mu
parameter becomes small, and the lightest neutralinos become higgsino-like; in
this case, radiative branching fraction can reach the 1% level. Our MSSM
analysis includes a scan over independent positive and negative gaugino masses.
We show branching fractions can reach the 10-100% level even for large values
of the parameter tan(beta). These regions of parameter space are realized in
supergravity models with non-universal gaugino masses. Measurement of the
radiative neutralino branching fraction may help pin down underlying parameters
of the fundamental supersymmetric model.Comment: 19 page JHEP file with 8 PS figures; previous version contained
figure misplacemen
New allowed mSUGRA parameter space from variations of the trilinear scalar coupling A0
In minimal Supergravity (mSUGRA) models the lightest supersymmetric particle
(assumed to be the lightest neutralino) provides an excellent cold dark matter
(CDM) candidate. The supersymmetric parameter space is significantly reduced,
if the limits on the CDM relic density, obtained from WMAP data, are used.
Assuming a vanishing trilinear scalar coupling A0 and fixed values of
tan(beta), these limits result in narrow lines of allowed regions in the
m0-m1/2 plane, the so called WMAP strips. In this analysis the trilinear
coupling A0 has been varied within +/-4 TeV. A fixed non vanishing A0 value
leads to a shift of the WMAP strips in the m0-m1/2 plane.Comment: Typos corrected, Fig.1. updated, references adde
Supersymmetric QCD corrections to and the Bernstein-Tkachov method of loop integration
The discovery of charged Higgs bosons is of particular importance, since
their existence is predicted by supersymmetry and they are absent in the
Standard Model (SM). If the charged Higgs bosons are too heavy to be produced
in pairs at future linear colliders, single production associated with a top
and a bottom quark is enhanced in parts of the parameter space. We present the
next-to-leading-order calculation in supersymmetric QCD within the minimal
supersymmetric SM (MSSM), completing a previous calculation of the SM-QCD
corrections. In addition to the usual approach to perform the loop integration
analytically, we apply a numerical approach based on the Bernstein-Tkachov
theorem. In this framework, we avoid some of the generic problems connected
with the analytical method.Comment: 14 pages, 6 figures, accepted for publication in Phys. Rev.
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
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
Theoretical uncertainties in sparticle mass predictions from computational tools
We estimate the current theoretical uncertainty in sparticle mass predictions
by comparing several state-of-the-art computations within the minimal
supersymmetric standard model (MSSM). We find that the theoretical uncertainty
is comparable to the expected statistical errors from the Large Hadron Collider
(LHC), and significantly larger than those expected from a future e+e- Linear
Collider (LC). We quantify the theoretical uncertainty on relevant sparticle
observables for both LHC and LC, and show that the value of the error is
significantly dependent upon the supersymmetry (SUSY) breaking parameters. We
also present the theoretical uncertainty induced in fundamental-scale SUSY
breaking parameters when they are fitted from LHC measurements. Two regions of
the SUSY parameter space where accurate predictions are particularly difficult
are examined in detail: the large tan(beta) and focus point regimes.Comment: 22 pages, 6 figures; comment added pointing out that 2-loop QCD
corrections to mt are incorrect in some of the programs investigated. We give
the correct formul
TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider
The TESLA Technical Design Report Part III: Physics at an e+e- Linear
ColliderComment: 192 pages, 131 figures. Some figures have reduced quality. Full
quality figures can be obtained from http://tesla.desy.de/tdr. Editors -
R.-D. Heuer, D.J. Miller, F. Richard, P.M. Zerwa
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