arXiv subjects

A. Arhrib

Publications and source records attributed to A. Arhrib.

43 records · Page 3Linked to original sources

arXiv1997

SUSY Higgs Boson Decays into Scalar Quarks: QCD Corrections

In supersymmetric theories, the decays of the neutral CP-even and CP-odd as well as the charged Higgs bosons into scalar quarks, in particular into top and bottom squarks, can be dominant if they are kinematically allowed. We calculate the QCD corrections to these decay modes in the minimal supersymmetric extension of the Standard Model, including all quark mass terms and squark mixing. These corrections turn out to be rather large, altering the decay widths by an amount which can be larger than 50%. The corrections can be either positive or negative, and depend strongly on the mass of the gluino. We also discuss the QCD corrections to the decays of heavy scalar quarks into light scalar quarks and Higgs bosons.

hep-ph↗

arXiv1996

Radiative corrections to $e^+e^-\to H^+ H^-$

We study the 1-loop corrections to the charged Higgs production both in the Minimal Supersymmetric Standard Model (MSSM) and in a more general type II two-Higgs-doublet model (THDM-II). We consider the full set of corrections (including soft photon contributions as well as box diagrams), and define a parametrization that allows a comparison between the two models. Besides the soft photon radiation there can be prominent model-dependent effects.

hep-ph↗

arXiv1996

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 $e^+e^-$ 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.

hep-ph↗

arXiv1996

Triple Gauge Boson Couplings

We present the results obtained by the "Triple Gauge Couplings" working group during the LEP2 Workshop (1994-1995). The report concentrates on the measurement of $WWγ$ and $WWZ$ couplings in $e^-e^+\to W^-W^+$ or, more generally, four-fermion production at LEP2. In addition the detection of new interactions in the bosonic sector via other production channels is discussed.

hep-ph↗

arXiv1995

MSSM radiative contributions to the WW$γ$ and WWZ form factors

We evaluate one-loop contributions to the C and P conserving $WWγ, WWZ$ form factors in the Minimal Supersymmetric Standard Model (MSSM), and in a more constrained Supergravity Grand Unified Theory (SUGRA-GUT). A systematic search of maximal effects in the available parameter space, shows that at LEP2 energy MSSM contributions can hardly reach the border of the most optimistic accuracy expected on those couplings, even for particles close to their production thresholds. At NLC energies, the effects are more comfortably of the order of the expected sensitivity, and may therefore provide useful information on MSSM parameter values which will not be available from direct particle production. We also discuss briefly some variance with other studies.

hep-ph↗

arXiv1995

QCD corrections to scalar quark pair production in e+e- annihilation

We calculate the QCD radiative corrections to the production of supersymmetric scalar partners of quarks in e+e- annihilation. We include both the standard gluonic corrections and the genuine supersymmetric QCD corrections due to quark--gluino loops, and allow for mixing between left-- and right--handed scalar quarks which leads to the possibility that the two final state particles have different masses. The corrections are found to be much larger than the ones affecting the production of spin 1/2 particles.

hep-ph↗

arXiv1994

Fermion and Sfermion Effects in $e^+ e^-$ charged Higgs pair production

Top and bottom one loop corrections to $e^+e^-\rightarrow H^+ H^-$ are considered at NLC energies and found to be significantly large and negative over the full range of $tan \, β$. Moreover, loop effects of moderately heavy squarks and sleptons in the minimal supersymmetric extension of the standard model, tend to cancel partly or fully these large corrections, thus providing a useful indirect information about the supersymmetric sector. The overall effect can still range between $-25 \%$ and $+25 \%$, however lies typically around $-10 \%$ in a wide range of the model parameters.

hep-ph↗