285 research outputs found
Threshold and Flavour Effects in the Renormalization Group Equations of the MSSM II: Dimensionful couplings
We re-examine the one-loop renormalization group equations (RGEs) for the
dimensionful parameters of the minimal supersymmetric Standard Model with
broken supersymmetry, allowing for arbitrary flavour structure of the soft SUSY
breaking (SSB) parameters. We include threshold effects by evaluating the
-functions in a sequence of (non-supersymmetric) effective theories with
heavy particles decoupled at the scale of their mass. We present the most
general form for high scale SSB parameters that obtains if we assume that the
supersymmetry breaking mechanism does not introduce new inter-generational
couplings. This form, possibly amended to allow additional sources of
flavour-violation, serves as a boundary condition for solving the RGEs for the
dimensionful MSSM parameters. We then present illustrative examples of
numerical solutions to the RGEs. We find that in a SUSY GUT with the scale of
SUSY scalars split from that of gauginos and higgsinos, the gaugino mass
unification condition may be violated by (10%). As another
illustration, we show that in mSUGRA, the rate for the flavour-violating
decay obtained using the complete RGE solution is
smaller than that obtained using the commonly-used "single-step" integration of
the RGEs by a factor 10-25, and so may qualitatively change expectations for
topologies from top-squark pair production at colliders. Together with the RGEs
for dimensionless couplings presented in a companion paper, the RGEs in
Appendix B of this paper form a complete set of one-loop MSSM RGEs that include
threshold and flavour-effects necessary for two-loop accuracy.Comment: 96 pages, 14 figures, revtex4, multirow.sty, bm.sty, amsmath.sty;
Corrected Fig. 3 and Eqs. (B9), (B11), (B13) - (B20) and (B24). Results
change by less than 1
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