Charged Higgs Boson Pairs at the LHC

We compute the cross section for pair production of charged Higgs bosons at the LHC and compare the three production mechanisms. The bottom-parton scattering process is computed to NLO, and the validity of the bottom-parton approach is established in detail. The light-flavor Drell-Yan cross section is evaluated at NLO as well. The gluon fusion process through a one-loop amplitude is then compared with these two results. We show how a complete sample of events could look, in terms of total cross sections and distributions of the heavy final states.Comment: 15 pages with 8 figure

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 semi-blind approach to optimize turbo decoding for a cauchy α-stable impulsive noise channel

Knowledge of the noise parameters that contaminate the signal sent is  very important for many communication systems. In this work, we propose a new method to estimate the dispersion parameter of a  symmetric α-stable impulse noise (SαS) of Cauchy, from the received signal only at the iterative decoder (turbo decoder). This method is based on the FLOS (Fractional Lower Order Statistics) and the probability that binds the received signal and the signal sent in BPSK modulation (Binary Phase Shift Keying). The results obtained, in terms of RMSE (Root Mean Square Error) and BER (Bit Error Rate) show the precision and the efficiency of our approach.Keywords: Cauchy impulse noise SαS, dispersion parameter, FLOS, RMSE, BER

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

Homogenous UV/Periodate Process for the Treatment of Acid Orange 10 Polluted Water

The photoactivated periodate (UV/IO4−) process is used to investigate the degradation of acid orange 10 (AO10) dye. The photodecomposition of periodate ions produces highly reactive radicals (i.e., •OH, IO3•, and IO4•) that accelerate dye degradation. Increasing the initial concentration of periodate to 3 mM enhances the dye removal rate, but over 3 mM periodate, the degradation rate slows down. On the contrary, increasing initial dye concentrations reduces the degradation performance. pH is the most critical factor in AO10 breakdown. Salts slow down the degradation of the dye. However, UV/IO4− is more efficient in distilled water than natural water. Even at low concentrations, surfactants may affect the dye’s decomposition rate. The addition of sucrose reduced the breakdown of AO10. Although tertbutanol is a very effective •OH radical scavenger, it does not affect the dye breakdown even at the highest concentrations. Accordingly, the AO10 degradation is a non-•OH pathway route. According to retrieved data, the photoactivated periodate method eliminated 56.5 and 60.5% of the initial COD after 60 and 120 min of treatment time; therefore, it can be concluded that the UV/IO4− system may treat effluents, especially those containing textile dyes

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

Supersymmetric QCD corrections to e+e−→tbˉH−e^+e^-\to t\bar{b}H^- 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.

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

A T-odd asymmetry in neutralino production and decay

We study CP-violating effects in neutralino production and subsequent decay within the Minimal Supersymmetric Standard Model with complex parameters M_1 and mu. The observable we propose is a T-odd asymmetry based on a triple product in neutralino production e^+ e^- -> tilde{chi}^0_i tilde{chi}^0_2, i = 1,...,4, with subsequent leptonic three-body decay tilde{chi}^0_2 -> tilde{chi}^0_1 l^+ l^-, l = e, mu, at an e^+ e^- linear collider with sqrt{s} = 500 GeV and polarised beams. We provide compact analytical formulae for the cross section and the T-odd asymmetry taking into account the complete spin correlations between production and decay. We give numerical predictions for the cross section and the T-odd asymmetry. The asymmetry can go up to 10 %.Comment: 28 pages, LaTeX, 10 figures; v2: typos corrected, published versio