相关论文: Some comments on B -> pi pi decays

Using the perturbative QCD amplitudes for $B\to \pi\pi$ and $B\to K\pi$, we have performed an extensive study of the parameter space where the theoretical predictions for the branching ratios are consistent with recent experimental data.…

An isospin analysis of $B\to \pi\pi$ decays yields $\sin 2\alpha$, where $\alpha$ is the usual CKM angle $\alpha\equiv {\rm arg} [-V_{td} V_{tb}^\ast/(V_{ud}V_{ub}^\ast)]$ without hadronic uncertainty if isospin is a perfect symmetry. Yet…

Based on a sample of 227 million BBbar pairs collected by the BaBar detector at the PEP-II asymmetric-energy B Factory at SLAC, we measure the branching fraction B(B0 -> pi0pi0) = (1.17 +- 0.32 +- 0.10) x 1e-6, and the asymmetry C(pi0pi0) =…

We discuss a potential discrepancy in an approximate relation among $B \to K \pi$ rates which, with increased statistical significance, would imply new physics in $\Delta I=1$ transitions. An approximate relation between CP-violating rate…

Within the Standard Model, CP rate asymmetries for $B\to K^-\pi^{+,0}$ could reach 10%. With strong final state phases, they could go up to 20--30%, even for $\bar K^0\pi^-$ mode which would have opposite sign. We can account for…

We present a method for measuring the weak phase gamma using isospin analysis of three body B decays into K pi pi channels. Differential decay widths and time dependent asymmetry in B_d -> K_s pi^+pi^- mode needs to be measured into even…

As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. In this paper, we reconsider this approach in the light of recent CLEO data, which look very…

The decay $B^0 \to K^0 \pi^0$, dominated by a $b \to s$ penguin amplitude, holds the potential for exhibiting new physics in this amplitude. In the pure QCD penguin limit one expects $\ckp = 0$ and $\skp = \sin 2 \beta$ for the coefficients…

We present a measurement of CP-violating asymmetries in B0 -> pi+pi- decays based on a 41.8 fb-1 data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We fully reconstruct…

We present an improved measurement of CP-violating asymmetries in B0 -> pi+ pi- decays based on a 78 fb^-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We reconstruct one…

We study the CP asymmetries in $B^+$, $D^+$, and $K^+$ decays into $\pi^+\pi^0$. These asymmetries are commonly known to vanish in the isospin limit. We clarify what is meant by the term ``isospin limit" in this context. We provide a…

We present a bound on the weak phase $\alpha$ from isospin-breaking effects in weak radiative decays, which requires the CP-averaged branching ratios for the weak radiative decays $B^\pm\to \rho^\pm \gamma$, $B^0\to \rho^0/\omega \gamma$,…

In this paper, we draw constraints on the Cabibbo-Kobayashi-Maskawa (CKM) angle $\alpha$ and the strong phase $\delta$ from the experimental measurements of $\ssb$, the CP-violating asymmetries and branching ratios of $B \to \pi^+ \pi^-,…

We argue that the observation of a sizable direct CP asymmetry A_{CP} in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, A_{CP} can be calculated reliably and is found to be below 1% in…

A sum rule relation is proposed for direct CP asymmetries in $B\to K\pi$ decays. Leading terms are identical in the isospin symmetry limit, while subleading terms are equal in the flavor SU(3) and heavy quark limits. The sum rule predicts…

We discuss several issues related to direct CP violation in rare $B$ meson decays. We review the use of CP asymmetries in extracting information of strong and weak phases, how the experimental data fit into the overall picture, and the…

To observe CP-violating asymmetries through the interference of a weaker amplitude with a stronger one in $\bo \to D^{(*)} \pi$ and $\ob \to D^{(*)} \pi$ decays, one must collect enough events that the intensity associated with the weaker…

As we pointed out recently, the neutral decays $B_d\to\pi^\mp K^\pm$ and $B_d\to\pi^0K$ may provide non-trivial bounds on the CKM angle $\gamma$. Here we reconsider this approach in the light of recent CLEO data, which look very…

We compute CP asymmetries of one-particle inclusive B(s) --> D(s) X decay rates. We find that the weak angle gamma could in principle be extracted from these asymmetries although they are very small. Taking the decay width difference into…

We report on a search for the CP asymmetry in the singly Cabibbo-suppressed decays D+ -> KKpi and in the resonant decays D+ -> phipi and D+ -> KstarK based on a data sample of 79.9 fb^-1 recorded by the BABAR detector. We use the…