Stefan Schacht

SU(3)-flavor anatomy of nonleptonic charm decays

We perform a comprehensive SU(3)-flavor analysis of charmed mesons decaying to two pseudoscalar SU(3)-octet mesons. Taking into account SU(3)-breaking effects induced by the splitting of the quark masses, m_s != m_{u,d}, we find that existing data can be described by SU(3)-breaking of the order 30%. The requisite penguin enhancement to accomodate all data on CP violation tends to be even larger than the one extracted from Delta a_{CP}^{dir}(K^+K^-,pi^+pi^-) alone, strengthening explanations beyond the standard model. Despite the large number of matrix elements, correlations between CP asymmetries allow potentially to differentiate between different scenarios for the underlying dynamics, as well as between the standard model and various extensions characterized by SU(3) symmetry and its subgroups. We investigate how improved measurements of the direct CP asymmetries in singly-Cabibbo-suppressed decays can further substantiate the interpretation of the data. We show that particularly informative are the asymmetries in D->pi^+pi^- versus D->K^+K^-, D_s->K_S pi^+ versus D^+->K_S K^+, D^+->pi^+ pi^0, D->pi^0pi^0, and D->K_S K_S.

Squark flavor implications from \( \bar{B} \to {\bar{K}^{{( * )}}}{l^{ + }}{l^{ - }} \)

A bstractRecent experimental and theoretical progress regarding

Topological amplitudes in

\bar{B} \to {K^{{( * )}}}{l^{ + }}{l^{ - }}

D

decays led to improved bounds on the Wilson coefficients C9 and C10 of four-fermion operators of the |ΔB| = |ΔS| = 1 effective Hamiltonian. We analyze the resulting implications on squark flavor violation in the MSSM and obtain new constraints on flavor-changing leftright mixing in the up-squark-sector. We find the dimensionless flavor mixing parameter

decays to two pseudoscalars: A global analysis with linear

{(\delta_{{23}}^{\mu })_{{LR}}}

SU(3)_F

, depending on the flavor-diagonal MSSM masses and couplings, to be as low as ≲ 0.1. This has implications for models based on radiative flavor violation and leads to

breaking

\mathcal{B}({\bar{B}_s} \to {\mu^{ + }}{\mu^{ - }}) \gtrsim 1 \times {10^{ - }}^9

Standard model predictions and new physics sensitivity in

. Rare top decays t → cγ,t → cg,t → cZ have branching ratios predicted to be below ≲ few × 10−8, 10−6 and 10−7, respectively.

B \to DD

We study decays of

decays

D^0