相关论文: Rare radiative charm decays in the standard model …
Flavor changing neutral currents (FCNCs) in the charm system are highly suppressed in the standard model (SM). The theoretical strategies used to suppress FCNCs induced by supersymmetry in the strange and beauty systems need not apply to…
We briefly review the status of rare radiative and semileptonic $b \to s (\gamma, \ell^+ \ell^-)$, ($\ell=e,\mu$) decays. We discuss possible signatures of new physics in these modes and emphazise the role of the exclusive channels. In…
We explore the sensitivity of the flavour changing neutral currents among c and u quarks in the context of the Minimal Supersymmetric Standard Model. The standard model rate for c->u gamma can be enhanced by up to two orders of magnitudes…
This study examines the rare decay $B \to K_0^*(1430)\,\ell^+ \ell^-$ as a possible probe for new physics beyond the standard model (SM). We first analyze this channel within the SM and then include scalar leptoquark (LQ) contributions. We…
The Standard Model predictions for $D^0$-$\bar{D}^0$ mixing and CP violation in $D$ decays are revised. The emphasis is put on obtaining the order of magnitude of the effects. In the case of mixing, the different approaches to the long…
Several deviations from the Standard Model predictions have been recently observed in the decays mediated by $b \rightarrow s l^+ l^-$ transitions. These could be pointing towards new vector-current contributions or could be explained by…
We point out that a simple test of the mechanism of CP violation can be performed by a measurement of the CP asymmetries in exclusive and inclusive radiative rare decays. We show that the rate asymmetries $\Delta \Gamma = \Gamma(B^- \to f…
Top flavour-changing neutral decays are extremely suppressed within the Standard Model (SM) by the GIM mechanism, but can reach observable rates in some of its extensions. We compute the branching ratios for t -> c gamma and t -> c g in…
We review the NLL QCD calculations for the branching ratio of B -> X_s gamma in the SM. In particular, we emphasize the problem related to the definition of the charm quark mass which leads to a rather large uncertainty of the NLL…
Rare $\vert \Delta c \vert=\vert \Delta u \vert=1$ processes uniquely probe flavor in the Standard Model and beyond from the up-type quark sector. Opportunities to search for BSM physics in charm arise from the severe GIM suppression which…
A comprehensive review of weak decays of charmed hadrons ($D^{0/+}$, $D^+_s$ and $\Lambda^+_c$) based on analyses of the threshold data from $e^+e^-$ annihilation in the BESIII experiment is presented. Current experimental challenges and…
Rare $\Lambda_b\to\Lambda l^+l^-$ and $\Lambda_b\to\Lambda\gamma$ decays are investigated in the relativistic quark model based on the quark-diquark picture of baryons. The decay form factors are calculated with the account of all…
The rare decay $B^+ \to D_s^+ \phi $ can occur only via annihilation type diagram in the standard model. The small branching ratio predicted in the standard model makes this channel sensitive to new physics contributions. We analyze this…
Applying the perturbative QCD ( PQCD ) method, we study the decay $B_c\rightarrow D_s^*\gamma$ in the standard model and multiscale walking technicolor model. In the SM, we find that the contribution of weak annihilation is more important…
A class of meson decay modes sensitive to only one quark topology at leading G_F order (annihilation of valence quarks through a W) is described. No experimental observations, nor even upper limits, have been reported for these decays. This…
The results of several studies of charmed mesons and baryons at BABAR are presented. First, searches for the rare decays D0 --> l+ l- are presented and new upper limits on these processes are established. Second, a measurement of the…
The SuperB experiment at the Cabibbo Laboratory will provide new possibilities to study the physics of charm. The potential physics reach of the experiment when performing studies of rare decays, mixing and CP violation in charm decays is…
Precision results on the leptonic, semileptonic, and hadronic decays of charm mesons are reviewed. These results are important for timely progress in weak flavor physics both in their own right and as checks of theoretical calculations.…
We review the experimental measurements and theoretical descriptions of leptonic and semileptonic decays of particles containing a single heavy quark, either charm or bottom. Measurements of bottom semileptonic decays are used to determine…
Recently observed increase of direct CP asymmetry in charm meson nonleptonic decays is difficult to explain within the SM. If this effect is induced by new physics, this might be investigated in other charm processes. We propose to…