相关论文: Long distance contributions in $D \to V \gamma$ de…

The weak radiative Cabibbo allowed decays D^+ -> anti K^0 pi^+ gamma and D^0 -> K^- pi^+ gamma with nonresonant K pi are investigated by relying on the factorization approximation for the nonleptonic weak transitions and the model which…

We present a detailed analysis of the $D \to V \gamma $ transitions, using a model which combines heavy quark effective theory and the chiral Lagrangian approach and includes symmetry breaking. We notice that in addition to the previously…

The Cabibbo suppressed decays $D\to Vl^+l^-$ (V is light vector meson) present in principle the opportunity to observe the short distance FCNC transition $c\to ul^+l^-$, which is sensitive to physics beyond the Standard Model. We analyze…

The short-distance contribution due to the $c\to u\gamma$ penguin as well as long-distance contributions are considered in an analysis of $D\to V\gamma$ decays, the latter being dominant. The matrix elements for nine $D\to V\gamma$…

A systematic approach to long-distance effects in exclusive radiative weak $B$ decays is presented, based on a combination of the heavy quark limit with perturbative QCD. The dominant long-distance effects, connected with weak annihilation…

We analyze the short and long distance contributions to inclusive $B \rightarrow X_d \gamma$ decay, paying particular attention to the dependence on the Cabibbo-Kobayashi-Maskawa parameter $V_{td}$. We discuss penguin diagrams with internal…

We present first calculations of new long-distance contributions to $B_s \to \gamma \gamma$ decay due to intermediate $D_s$ and $D_s^*$ meson states. The relevant $\gamma$ vertices are estimated using charge couplings and transition moment…

We present a calculation of the rare decay mode D^0 -> gamma gamma, in which the long distance contributions are expected to be dominant. Using the Heavy Quark Chiral Perturbation Theory Lagrangian with a strong g coupling as recently…

We propose a method to determine the angle $\gamma=arg(V_{ub})$, using the $B\to D^*V$ ($V=K^*, \rho$) modes. The $D^*$ is considered to decay to $D \pi$. An interference of the $B \to D^{*0}V$ and $B \to \bar {D^{*0}}V$ amplitudes is…

We estimate the long distance (LD) contribution to the magnetic part of the $s \to d\gamma$ transition using the Vector Meson Dominance approximation $(V=\rho,\omega,\psi_i)$. We find that this contribution may be significantly larger than…

The various decay modes of the type $B \to \gamma D^* $ are dynamically different. In general there are factorizable contributions, and there are pole diagrams and pseudoscalar exchange contributions at meson level. The purpose of this…

The interference between Cabibbo-favoured and Cabibbo-suppressed $B\to D\pi$ decay amplitudes provides sensitivity to the CKM angle $\gamma$. The relative size of the interfering amplitudes is an important ingredient in the determination of…

Combining heavy quark effective theory and the chiral Lagrangian approach we investigate D meson radiative decays. First, we reanalyse $D^{*} \rightarrow D \gamma$ decays using heavy quark spin symmetry, chiral symmetry Lagrangian, but…

We study a new $K\rightarrow\pi\pi$ decay channel with gluons in intermediate state which is normally neglected within the factorization framework. Both short-distance and long-distance parts of the amplitude are calculated. The chiral…

We investigate Cabibbo suppressed $D^{0}$, $D^{+}$ and $D^{+}_{s}$ radiative weak decays in order to find the best mode to test $c\to u \gamma$ decay. Combining heavy quark effective theory and the chiral Lagrangian approach we determine…

We estimate the long distance contribution to the $K^+ \rightarrow \pi^+ \nu \bar\nu$ decay amplitude using chiral perturbation theory. We find that it is likely to be less than a few percent of the part of the short distance contribution…

We consider the long distance contributions to inclusive penguin processes through processes like $b\rightarrow s V$ and $b\rightarrow d V$ where $V$ are $^3S_1(c\bar c)$ states $\psi_i$ in the former case and include $\rho$, $\omega$ for…

Long-distance contributions to the $D^0$-$\bar D^0$ mixing parameters $x$ and $y$ are evaluated using latest data on hadronic $D^0$ decays. In particular, we take on two-body $D \to PP$ and $VP$ decays to evaluate the contributions of…

We re-estimate the decay branching ratio of $B_s\to 2\gamma$ through $D_s^+D_s^-$ and $D_s^{*+}D_s^{*-}$ intermediate states, in the effective Lagrangian approach. We find that the branching ratio does not exceed a few times $10^{-7}$,…

The dominant long-distance contributions to the exclusive radiative decays $B \to \rho (\omega) + \gamma$ involve photon emission from the light quarks at large distances, which cannot be treated perturbatively. We point out that this…