Guy Raz

Constraining the phase of Bs-Bs mixing.

New physics contributions to Bs-Bs mixing can be parametrized by the size (rs2) and the phase (2thetas) of the total mixing amplitude relative to the standard model amplitude. The phase has so far been unconstrained. We first use the D0 measurement of the semileptonic CP asymmetry ASL to obtain the first constraint on the semileptonic CP asymmetry in Bs decays, ASLs=-0.008+/-0.011. Then we combine recent measurements by the CDF and D0 Collaborations--the mass difference (DeltaMs), the width difference (DeltaGammas), and ASL;s--to constrain 2thetas. The errors on DeltaGammas and ASL;s should still be reduced to have a sensitive probe of the phase, yet the central values are such that the regions around 2thetas approximately 3pi/2 and, in particular, 2thetas approximately pi/2, are disfavored.

Quark-squark alignment reexamined

We re-examine the possibility that the solution to the supersymmetric flavor problem is related to small mixing angles in gaugino couplings induced by approximate horizontal Abelian symmetries. We prove that, for a large class of models, there is a single viable structure for the down quark mass matrix with four holomorphic zeros. Consequently, we are able to obtain both lower and upper bounds on the supersymmetric mixing angles and predict the contributions to various flavor changing neutral current processes. We find that the most likely signals for alignment are

Constraining the Phase ofBs−B¯sMixing

\Delta m_D

Time variations in the scale of grand unification

close to the present bound, significant CP violation in

Mass insertion approximation without squark degeneracy

D^0-\bar{D^0}

Suppression of flavor symmetry breaking in B decay sum rules

mixing, and shifts of order a few percent in various CP asymmetries in

Interpreting experimental bounds on D0 - anti-D0 mixing in the presence of CP violation

B^0

Using SU(3) relations to bound the CP asymmetries in B{yields}KKK decays

and

SU(3) relations and the CP asymmetry in B ---> K(S) K(S) K(S)

B_s

SU(3) Relations and the CP Asymmetry in

decays. In contrast, the modifications to radiative B decays, to