New bound on penguin pollution in B^0(t) --> pi^+ pi^-

We show how B -> pi pi decays can be used to search for new physics in the b -> d flavour-changing neutral current. One needs one piece of theoretical input, which we take to be a prediction for P/T, the ratio of the penguin and tree amplitudes in Bd -> pi+ pi-. If present, new physics can be detected over most of the parameter space. If \alpha (\phi_2) can be obtained independently, measurements of B+ -> pi+ pi0 and Bd/Bd(bar) -> pi0 pi0 are not even needed.

From a time-dependent analysis of the decay $B^0_{d} \to \pi^+ \pi^-$ and using a model-dependent $A_P/A_T$ ratio of the penguin-to-tree amplitudes contributing to the decay, both the weak phase $\alpha$ and the strong phase shift difference $\delta$ can be extracted from the data. The value of the weak phase $\beta$, expected to be measured from the decay $B^0_{d} \to J/\psi K_S$, is used to parameterize the value of $A_P/A_T$ and the corresponding penguin correction to the ...

Oscillation effects in B0 -> Ks D0 and related processes are considered to determine delta=beta-alpha+pi. We suggest that D0 decays to CP eigenstates used in concert with inclusive D0 decays provide a powerful method for determining delta cleanly i.e. without any complication from penguin processes. The CP asymmetry is expected to be <=40% for D0 decays to non-CP eigenstates and <=80% for decays to CP eigenstates. This method can lead to a fairly accurate determination of del...

Recent results of the standard model expectations on sin2beta(phi_1) from penguin-dominated b to s decays are briefly reviewed.

We discuss the correlations of charming penguin contributions to $B\to\pi\pi$, $\pi K$ and KK using approximate flavor SU(3) symmetry. Strong constraints are found from the direct CP asymmetries especially in $\pi K$ modes. We make a global fit to the latest data and find that only a small charming penguin is allowed, and the size of color-suppressed tree amplitude (C) relative to tree amplitudes (T) remains large $C/T\simeq0.6$, which disfavors the possibility of a large cha...

Constraints on angles of Unitarity triangle are reviewed, and in particular constraint on $\gamma$ from limit on $\Delta m_s$ is emphasized. Effects of penguin diagram on measurement of $\beta$ and $\alpha$ are then reviewed. New measurements on $B \to \pi^+\pi^-$ in QCD improved factorization approximation suggest large penguin effects. It is possible to estimate the error in measurement of $\alpha$ as a function of $\gamma$ for different $|V_{ub} /V_{cb}|$ values.

Electroweak penguin operators become important when $m_t \approx 174$ GeV. We discuss their implications for measuring CP violating phases $\alpha$, $\beta$ and $\gamma$.

We study the influence of penguin (especially, electroweak penguin) effects on some methods of measuring the angles $\alpha$, $\beta$, and $\gamma$ in the CKM unitarity triangle. We use next-to-leading order effective Hamiltonian, and present numerical estimates based on the factorization approximation. We find that some techniques suggested in the literature, especially for $\alpha$ determination, are not workable in light of the electroweak penguin effects. Nevertheless, th...

This talk contains a short overview of the history of the interplay of the weak and the strong interaction and CP-violation. It describes the phenomenology and the basic physics mechanisms involved in the Standard Model calculations of $K\to\pi\pi$ decays with an emphasis on the evaluation of Penguin operator matrix-elements.

We derive model independent lower bounds on the CKM parameters (1-rhobar) and etabar as functions of the mixing-induced CP asymmetry S in B-> pi+ pi- and sin(2 beta) from B->psi K_S. The bounds do not depend on specific results of theoretical calculations for the penguin contribution to B-> pi+ pi-. They require only the very conservative condition that a hadronic phase, which vanishes in the heavy-quark limit, does not exceed 90 degrees in magnitude. The bounds are effective...