1 Introduction - Caltech High Energy Physics - California Institute of ...

5.3 Supersymmetry 389
Table 5-11. Correlated signatures for an observation of SφK much smaller than SψK, assuming a single
SUSY d-squark insertion of the type indicated. The ± signs represent the sign of the corresponding
observable.
LL RR LR RL
(δ d 23) O(1) O(1) O(10 −2 ) O(10 −2 )
SUSY masses < ∼ 300 GeV < ∼ 300 GeV < ∼ TeV < ∼ TeV
CφK −, small −, small −, small −, can be large
B(B → φK) SM-like SM-like varies varies
A b→sγ
CP +, few % SM-like +, O(10%) SM-like
∆mBs can be large can be large SM-like SM-like
Table 5-11 summarizes the correlations for each type of insertion. Of course, more than one insertion may
be present, so one could generate large deviations in SφK with an LR insertion and large ∆mBs with an LL
insertion. Such combinations can be read off of the table.
In conclusion, observation of a significant (or any) deviation in the CP asymmetries in B → φK 0 S could be
an early and strong indication of SUSY flavor physics. But it is the correlations between the φK 0 S signal and
other observables that will lead us to a deeper understanding of flavor in the MSSM.
5.3.2 SUSY at the Super B Factory
>– T. Goto, Y. Okada, Y. Shimizu, T. Shindou, and M. Tanaka –<
The Unitarity triangle and rare decays in three SUSY models
Among various candidates of physics beyond the Standard Model, SUSY is regraded as the most attractive
possibility. The weak scale SUSY provides a solution of the hierarchy problem in the Standard Model.
Although an extreme fine-tuning is necessary to keep the weak scale very small compared to the Planck
scale within the Standard Model , SUSY theory does not have this problem, because of the cancellation of
the quadratic divergence in the scalar mass renormalization. SUSY has attracted much attention since early
1990’s, when three gauge coupling constants determined at LEP and SLC turned out to be consistent with
the coupling unification predicted in SUSY GUT.
One of main motivations of the LHC experiment is a direct search for SUSY particles. The mass reach of
colored SUSY particles will be about 2 TeV, an order-of-magnitude improvement from the present limit. It
is quite likely that some signal of SUSY can be obtained in the early stage of the LHC experiment. It is
therefore important to clarify the role of SUSY studies at a Super B Factory in the LHC era.
In order to illustrate how B physics can provide useful information to distinguish various SUSY models, we
study SUSY effects in the length and angle measurements of the unitarity triangle and rare B decays for the
following four cases in three SUSY models [158, 159, 99].
• Minimal supergravity model
• SU(5) SUSY GUT with right-handed neutrinos: Case 1 (degenerate case)
• SU(5) SUSY GUT with right-handed neutrinos: Case 2 (non-degenerate case)
• MSSM with a U(2) flavor symmetry
The Discovery Potential of a Super B Factory