Revisiting B\to\pi K, \pi K^{\ast} and \rho K decays: CP violations and implication for New Physics

Combining the up-to-date experimental information on $B\to\pi K, \pi K^{\ast}$ and $\rho K$ decays, we revisit the decay rates and CP asymmetries of these decays within the framework of QCD factorization. Using an infrared finite gluon propagator of Cornwall prescription, we find that the time-like annihilation amplitude could contribute a large strong phase, while the space-like hard spectator scattering amplitude is real. Numerically, we find that all the branching ratios and most of the direct CP violations, except $A_{CP}(B^{\pm}\to K^{\pm}\pi^{0})$, agree with the current experimental data with an effective gluon mass $m_g\simeq0.5 {\rm GeV}$. Taking the unmatched difference in direct CP violations between $B\to\pi^{0} K^{\pm}$ and $\pi^{\mp}K^{\pm}$ decays as a hint of new physics, we perform a model-independent analysis of new physics contributions with a set of $\bar{s}(1+\gamma_{5})b\otimes\bar{q}(1+\gamma_{5})q$ (q=u,d) operators. Detail analyses of the relative impacts of the operators are presented in five cases. Fitting the twelve decay modes, parameter spaces are found generally with nontrivial weak phases. Our results may indicate that both strong phase from annihilation amplitude and new weak phase from new physics are needed to resolve the $\pi K$ puzzle. To further test the new physics hypothesis, the mixing-induced CP violations in $B\to\pi^{0}K_{S}$ and $\rho^{0}K_{S}$ are discussed and good agreements with the recent experimental data are found.Comment: Version published in JHE

Reforming WTO Discipline on Export Duties: Sovereignty Over Natural Resources, Economic Development and Environmental Protection

The current World Trade Organization (WTO) regime on export restraints comprises two extremes: at one end is the near-complete freedom to levy export duties enjoyed by most Members, which renders theWTO discipline on export restrictions largely ineffective; at the other end, the rigid obligations imposed on several acceding Members prohibiting the use of export duties for any purpose.The recent WTO ruling in China-Raw Materials has only solidified the latter extreme. This article seeks to expose the irrationality of the current regime, especially the problems created by the rigid obligations of the several acceding Members. It contends that such obligations deprive these Members of their ownership right to claim a larger share of their natural resources for domestic use and of an effective tool for managing environmental externalities associated with the resource products exported.The virtual immutability of such obligations is at odds with the principle of permanent sovereignty over natural resources.To rectify these problems, this article proposes integrating all stand-alone export concessions into General Agreement on Tariffs andTrade (GATT) schedules, which would provide the acceding Members with the policy space and flexibility available under the GATT. It is also submitted that the key to gaining support from developing countries for the establishment of a system-wide discipline lies in the recognition of legitimate functions of export duties. Rather than pushing for their elimination, the WTO should aim to regulate export duties in the same manner as its regulation of import duties