2 research outputs found
SUSY-Induced Top Quark FCNC Processes at Linear Colliders
In the Minimal Supersymmetric Model (MSSM) the hitherto unconstrained flavor
mixing between top-squark and charm-squark will induce the flavor-changing
neutral-current (FCNC) interaction between top quark and charm quark, which
then give rise to various processes at the next generation linear collider
(NLC), i.e., the top-charm associated productions via ,
and collisions as well as the top quark rare decays
(, or ). All these processes involve the same part of the
parameter space of the MSSM. Through a comparative analysis for all these
processes at the NLC, we found the best channel to probe such SUSY-induced top
quark FCNC is the top-charm associated production in collision,
which occurs at a much higher rate than or collision and
may reach the detectable level for some part of the parameter space. Since the
rates predicted by the Standard Model are far below the detectable level, the
observation of such FCNC events would be a robust indirect evidence of SUSY.Comment: 12 pages, 8 figures (more refs added, discussions extended
Probing New Physics from Top-charm Associated Productions at Linear Colliders
The top-charm associated productions via , and collisions at linear colliders, which are extremely suppressed in the
Standard Model (SM), could be significantly enhanced in some extensions of the
SM. In this article we calculate the full contribution of the topcolor-assisted
technicolor (TC2) to these productions and then compare the results with the
existing predictions of the SM, the general two-Higgs-doublet model and the
Minimal Supersymmetric Model. We find that the TC2 model predicts much larger
production rates than other models and the largest-rate channel is , which exceeds 10 fb for a large part of the parameter
space. From the analysis of the observability of such productions at the future
linear colliders, we find that the predictions of the TC2 model can reach the
observable level for a large part of the parameter space while the predictions
of other models are hardly accessible.Comment: discussions added (version in Eur. Phys. J. C