Abstract
In a fertile patch of the string landscape which includes the Minimal Supersymmetric Standard Model (MSSM) as the low energy effective theory, rather general arguments from Douglas suggest a power-law statistical selection of soft breaking terms (m(soft)^n where n=2n_F+n_D-1 with n_F the number of hidden sector F-SUSY breaking fields and n_D the number of D-term SUSY breaking fields). The statistical draw towards large soft terms must be tempered by requiring an appropriate breakdown of electroweak (EW) symmetry with no contributions to the weak scale larger than a factor 2-5 of its measured value, lest one violates the (anthropic) atomic principle. Such a simple picture of stringy naturalness generates a light Higgs boson with mass m_h~ 125 GeV with sparticles (other than higgsinos) typically beyond LHC reach. Then we expect first and second generation matter scalars to be drawn independently to the tens of TeV regime where the upper cutoff arises from two-loop RGE terms which drive third generation soft masses towards tachyonic values. Since the upper bounds on m_0(1,2) are the same for each generation, and flavor independent, then these will be drawn toward quasi-degenerate values. This mechanism leads to a natural mixed decoupling/quasi-degeneracy solution to the SUSY flavor problem and a decoupling solution to the SUSY CP problem.
Highlights
The emergence of the string landscape picture [1,2,3,4,5] provides so far the only plausible mechanism for understanding the extreme suppression of the vacuum energy density of the universe ρvac = c2/(8π GN ) (3 meV)4 from its expected value ∼mP4
Assuming a multiverse [6] with a huge assortment of vacua states with cosmological constant (CC) uniformly distributed across the decades, those pocket universes with somewhat larger than our measured value would lead to such rapid expansion that galaxies would not condense, and presumably observers would not arise
Given the success of the landscape in predicting, can multiverse arguments be used to predict the scale of supersymmetry (SUSY) breaking [11,12]? A statistical approach to understanding the SUSY breaking scale has been advocated by Douglas [12,13]
Summary
For more complicated hidden sectors, the statistical draw toward large soft terms would be even stronger On, these considerations led to extensive debate over whether to expect high scale or weak scale SUSY breaking [11,12,25]. (mweak/msoft ) which follows the gross behavior of fine-tuning measures BG [32] ( EW) which compare the largest high scale (weak scale) SUSY breaking contribution to the size of the weak scale itself: the ansatz for fEWSB rewards vacua with soft terms that are closest to the magnitude of the weak scale itself. (1) A statistical peak was found at mh 125 ± 2 GeV This is easy to understand: we are selecting for soft terms as large as possible subject to appropriate EWSB and a value of mZPU 4mZmeas. The question is: how does this decoupling arise, and is it enough to solve these two SUSY issues?
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