The pure annihilation type decays Dd^0→Фγand Bs→ργ receive only colour suppressed penguin contributions with a very small branching ratio in the standard model. When we include the previously neglected electroma...The pure annihilation type decays Dd^0→Фγand Bs→ργ receive only colour suppressed penguin contributions with a very small branching ratio in the standard model. When we include the previously neglected electromagnetic dipole operator, the branching ratios can be enhanced to R（^-Bd^0→Фγ）≈ 1×10^-11 and R（^-Bs→ργ）～（6 - 16） ×10^-10, which are one order magnitude larger than previous study using the QCD factorization approach. The new effect can also give a large contribution, of order 10^-9, to transverse polarization of B→Фρ and B →ωФ, which is comparable to the longitudinal part. These effects can be detected in the LHCb experiment and the super-B factories.展开更多
The explicit expression of the transverse photon wavefunction φγ⊥（u, p2） at the leading twist with the on-shell and the off-shell momenta are calculated in the effective low-energy theory derived from the instant...The explicit expression of the transverse photon wavefunction φγ⊥（u, p2） at the leading twist with the on-shell and the off-shell momenta are calculated in the effective low-energy theory derived from the instanton vacuum of QCD, where both the space-like region as well as the time-like one of the momenta for the virtual photons are investigated. In addition, the problem about the consistency between the two different definitions of the transverse photon wavefunction with chiral-odd Dirac structure, σμν, has been considered, and proven to be true at the leading order by means of the sum rule method. A brief discussion of the dependence of the transverse light-cone photon wavefunction φγ⊥（u, p2） and its coupling, Fγ^⊥（u, P2） to the corresponding quark-antiquark current with respect to p^2, and that about the end-point behaviour of the transverse photon wavefunction is given.展开更多
Incoherent scattering of gamma rays from atoms is one of the basic processes of the interaction between light and matters. The experimentally measured differential cross section of coherent and incoherent scattering, ...Incoherent scattering of gamma rays from atoms is one of the basic processes of the interaction between light and matters. The experimentally measured differential cross section of coherent and incoherent scattering, the ratios of the two cross sections, and展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 10475085.
文摘The pure annihilation type decays Dd^0→Фγand Bs→ργ receive only colour suppressed penguin contributions with a very small branching ratio in the standard model. When we include the previously neglected electromagnetic dipole operator, the branching ratios can be enhanced to R（^-Bd^0→Фγ）≈ 1×10^-11 and R（^-Bs→ργ）～（6 - 16） ×10^-10, which are one order magnitude larger than previous study using the QCD factorization approach. The new effect can also give a large contribution, of order 10^-9, to transverse polarization of B→Фρ and B →ωФ, which is comparable to the longitudinal part. These effects can be detected in the LHCb experiment and the super-B factories.
基金Supported by the National Natural Science Foundation of China under Grant No 10075036, the BEPC National Laboratory Project R＆D and BES Collaboration Research Foundation.
文摘The explicit expression of the transverse photon wavefunction φγ⊥（u, p2） at the leading twist with the on-shell and the off-shell momenta are calculated in the effective low-energy theory derived from the instanton vacuum of QCD, where both the space-like region as well as the time-like one of the momenta for the virtual photons are investigated. In addition, the problem about the consistency between the two different definitions of the transverse photon wavefunction with chiral-odd Dirac structure, σμν, has been considered, and proven to be true at the leading order by means of the sum rule method. A brief discussion of the dependence of the transverse light-cone photon wavefunction φγ⊥（u, p2） and its coupling, Fγ^⊥（u, P2） to the corresponding quark-antiquark current with respect to p^2, and that about the end-point behaviour of the transverse photon wavefunction is given.
文摘Incoherent scattering of gamma rays from atoms is one of the basic processes of the interaction between light and matters. The experimentally measured differential cross section of coherent and incoherent scattering, the ratios of the two cross sections, and
