M. Beccaria

Sudakov expansions at one loop and beyond for charged scalar and fermion pair production in SUSY models at future linear colliders

We consider the high energy behavior of the amplitudes for pair production of charged leptons, quarks, Higgs bosons, sleptons, squarks and charginos at lepton colliders. We give the general expressions of the leading quadratic and subleading linear logarithms that appear at the one-loop level, and derive the corresponding resummed expansions to subleading logarithmic order accuracy. Under the assumption of a relatively light SUSY scenario and choosing the MSSM as a specific model, we compare the predictions of the one-loop and of the resummed expansions at variable energy. We show that the two predictions are very close in the one TeV regime, but drastically differ in the few (2,3) TeV range.

Stop-antistop and sbottom-antisbottom production at LHC: A One-loop search for model parameters dependence

We have computed the one-loop electroweak expression of diagonal and nondiagonal stop–antistop and sbottom–antisbottom production from initial state gluons at LHC. We have investigated the possibility that the one-loop effects exhibit a dependence on extra supersymmetric parameters different from the final squark masses. Our results, given for a choice of twelve SUSY benchmark points in the MSSM with mSUGRA symmetry breaking, show that in some cases a mild dependence might arise, at the percent relative level, of not simple experimental detection.

Single top-quark production in the t-channel at CERN LHC : A realistic test of electroweak models

We compute the complete electroweak one-loop effect on the process of

Associated production of a charged Higgs boson and top quark at LHC: The role of the complete electroweak supersymmetric contribution

t

Role of universal and nonuniversal Sudakov logarithms in four-fermion processes at TeV energies: The one-loop approximation reexamined

-channel single top production at LHC in the Standard Model and in the MSSM within the mSUGRA symmetry breaking scheme. We find that the one-loop electroweak SM effect is large, and decreases the cross section of an amount that is of the same size as that of the NLO QCD one. The genuine SUSY effect in the mSUGRA scheme, for a general choice of benchmark points, is rather small. It might become large and visible in more general scenarios around thresholds involving light stop and neutralino mass values.

SUSY scalar production in the electroweak Sudakov regime of lepton colliders

The process of charged Higgs production in association with a top quark at the LHC has been calculated at the complete next-to-leading-order electroweak level both in a two-Higgs-doublet model and in the minimal supersymmetric standard model, assuming a minimal supergravity breaking scheme. We have numerically explored the size of the one-loop corrections in two typical supersymmetric scenarios, with particular attention to the tan{beta} dependence, and we have found that they remain perturbatively small but possibly sizable, reaching a 20% limit for extreme values of tan{beta}, when the complete set of Feynman diagrams is taken into account.

Associated tW production at CERN LHC: A complete calculation of electroweak supersymmetric effects at one loop

We consider the separate effects on four-fermion processes, in the TeV energy range, produced at one loop by Sudakov logarithms of universal and nonuniversal kind, working in the t Hooft

Logarithmic SUSY electroweak effects on four fermion processes at TeV energies

ensuremath{xi}=1

Supersymmetry spectroscopy in stop-chargino production at CERN LHC

gauge. Summing the various vertex and box contributions allows us to isolate two quite different terms. The first one is a combination of vertex and box quadratic and linear logarithms that are universal and independent of the scattering angle

Supersymmetric virtual effects in heavy quark pair production at CERN LHC

ensuremath{theta}.