Search of Stop, Sbottom, $\tau$ -Sneutrino, and Stau at an $e^+e^-$ linear collider with $\sqrt{s}=0.5 - 2$ TeV

Abstract

We discuss pair production and decays of stops, sbottoms, τ -sneutrinos, and staus in e + e − annihilation in the energy range √ s = 500 GeV to 2 TeV.Numerical predictions within the Minimal Supersymmetric Standard Model (MSSM) for cross sections and decay rates are presented. We study the stop discovery potential for √ s = 500 GeV and 10 fb −1 integrated luminosity for polarized e − beams. Moreover, we give an estimate of the error of the softbreaking stop and sbottom parameters that can be obtained by cross section measurements with polarized e − beams.

Physics impact of a precise determination of the top quark mass at an e+e−linear collider

“…In figure 4 we show the allowed region in the mt 2 -m h plane, where the following values for the other parameters have been assumed [51,52]: mt 1 = 180 ± 1.25 GeV, cos θt = 0.57 ± 0.01, M A = 257 ± 10 GeV, µ = 263 ± 1 GeV, mg = 496 ± 10 GeV, A b = A t ± 30%, and a lower bound of 200 GeV has been imposed on the lighter sbottom mass. For tan β…”

Reconstruction of supersymmetric theories at high energy scales

“…Also in this case it has been shown that the mass matrix can be reconstructed [34,35]. The mass matrices for the first two generation sfermions have the same structure.…”

“…A t can be obtained from the mixing angle of the stop sector by measuring the stop production cross section in e + e − annihilation with different electron and/or positron polarizations [35]. In the cases A b and A τ the situation is more difficult, because these parameters influence the mixing angle in the sbottom and stau sector only weakly as evident from Eq.(11).…”

A CP sensitive asymmetry in the three-body decay

“…[3]. There it has been shown that by measuring production cross sections with polarized beams the masses of the top squarks mt 1 , mt 2 and their mixing angle θt can be determined.…”