Christopher Kolda

Cosmology of One Extra Dimension with Localized Gravity

We examine the cosmology of the two recently proposed scenarios for a five dimensional universe with localized gravity. We find that the scenario with a non-compact fifth dimension is potentially viable, while the scenario which might solve the hierarchy problem predicts a contracting universe, leading to a variety of cosmological problems.

Higgs mediated

We demonstrate a new source for flavor-changing neutral currents within the minimal supersymmetric standard model. At moderate to large tan {beta} , it is no longer possible to diagonalize the masses of the quarks in the same basis as their Yukawa couplings. This generates flavor-violating couplings of the form b{sub R}d{sub L}{phi} and b{sub R}s{sub L}{phi} where {phi} is any of the three neutral, physical Higgs bosons. These new couplings lead to rare processes in the B system such as B{sup 0}{yields}{mu}{sup +}{mu}{sup -} and B{sup 0}-B{sup 0} mixing. We show that the latter are anomalously suppressed, while the former is in the experimentally interesting range, with an observable signal possible at Run II of the Tevatron if m{sub A}(less-or-similar sign)400-700 GeV . (c) 2000 The American Physical Society.In this letter we demonstrate a new source for large flavor-changing neutral currents within the minimal supersymmetric standard model. At moderate to large tan(beta), it is no longer possible to diagonalize the masses of the quarks in the same basis as their Yukawa couplings. This generates large flavor-violating couplings of the form

B^0 \to \mu^{+} \mu^{-}

\bar b_R d_L H

in minimal supersymmetry

and

Kinetic mixing and the supersymmetric gauge hierarchy

\bar b_R s_L H

Flat directions in the scalar potential of the supersymmetric standard model

where H is any of the three neutral, physical Higgs bosons. These new couplings lead to rare processes in the B system such as

Higgs mediated tau ---> 3 mu in the supersymmetric seesaw model

B^0 -> \mu^+ \mu^-

Calculable upper limit on the mass of the lightest Higgs boson in perturbatively valid supersymmetric theories with arbitrary Higgs sectors.

decay and B-Bbar mixing. We show that the latter is anomalously suppressed, while the former is in the experimentally interesting range. Current limits on

Low-energy supersymmetry with D term contributions to scalar masses

B^0 -> \mu^+ \mu^-

The Higgs mass and new physics scales in the minimal standard model

already provide nontrivial constraints on models of moderate to large tan(beta), with an observable signal possible at Run II of the Tevatron if m_A < 400-600 GeV, extending to the TeV range if a proposed Run III of 30/fb were to occur.