[SLAC] [SLAC Pubs and Reports]

Constraints on Supersymmetric Soft Phases from Renormalization Group Relations


By using relations derived from renormalization group equations (RGEs), we find that strong indirect constraints can be placed on the top squark mixing phase in $A_t$ from the electric dipole moment of the neutron ($d_n$). Since $m_t$ is large, any GUT-scale phase in $A_t$ feeds into other weak scale phases through RGEs, which in turn contribute to $d_n$. Thus $CP$-violating effects due to a weak-scale $A_t$ are strongly constrained. We find that $|Im A_t^{EW}|$ must be smaller than or of order $|Im B^{EW}|$, making the electric dipole moment of the top quark unobservably small in most models. Quantitative estimates of the contributions to $d_n$ from $A_u$, $A_d$ and $B$ show that substantial fine-tuning is still required to satisfy the experimental bound on $d_n$. While the low energy phases of the $A$'s are not as strongly constrained as the phase of $B^{EW}$, we note that the phase of a universal $A^{GUT}$ induces large contributions in the phase of $B^{EW}$ through RGEs, and is thus still strongly constrained in most models with squark masses below a TeV.

(Equations render on Windows, Mac OS, AIX, Linux, Solaris, and IRIX with the techexplorer plug-in.)

Full Text


Compressed PostScript


More Information

Full bibliographic data for this document, including its complete author list, is (or soon will be) available from SLAC's SPIRES-HEP Database.

Please report problems with this file to posting@slac.stanford.edu. The SLAC preprint inventory is provided by the SLAC Technical Publications Department.
Page generated 01 May 2001 @ 13:58 PDT by htmlme.pl