相关论文: Puzzles in Cabibbo-Suppressed Charm Decays

We discuss semileptonic B decays of the form B -> J/Psi e nu X as possible probes of intrinsic charm. We calculate the leading order perturbative contribution to the process B- -> J/Psi e- nu_e X and find it to be unobservably small, with a…

Recently the D$^+$ charm meson was observed to have a clear branching ratio into the low energy $\pi-\pi$ sigma resonance, while this channel was not detected in the D$_s^+$ decay. It is shown that this is consistent with the standard…

Both Cabibbo allowed and doubly forbidden transitions contribute coherently to $D\rightarrow K_{S,L}+\pi 's$ decays. This leads to several intriguing and even quantitatively significant consequences, among them: (i) A difference between…

We report the first observation of two Cabibbo-suppressed decay modes, Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+. We observe 59+/-14 over a background of 87, and 22+/-8 over a background of 13 events, respectively, for 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…

Production of even-parity charmed mesons in hadronic B decays is studied. Specifically, we focus on the Cabibbo-allowed decays $\bar B\to D^{**}\pi$ and $\bar D^{**}_sD^{(*)}$, where $D^{**}$ denotes generically a p-wave charmed meson.…

We study the effects of models with a warped extra dimension on rare charm decays. While the new degrees of freedom in these models are bounded above a few TeV, they can leave signatures in rare charm decays with their tiny Standard Model…

Charm meson decay dynamics have been studied extensively over the last decade. We describe the Dalitz-plot analysis technique which has been applied by many experiments to three-body D0, D+ and Ds decays. We discuss experimental results…

We study the branching ratios and up-down asymmetries in the charmed baryon weak decays of ${\bf B}_c\to {\bf B}_DM$ with ${\bf B}_{c(D)}$ anti-triplet charmed (decuplet) baryon and $M$ pseudo-scalar meson states based on the flavor…

We review results on rare and forbidden decays of D^0, D^+, and D^+_s mesons from experiments at FNAL. The decay modes studied have two leptons in the final state and, if observed, would constitute evidence for flavor-changing…

We make a systematic investigation on the double charm decays of $B_c$ meson, by employing the perturbative QCD approach based on $k_T$ factorization. It is found that the non-factorizable emission diagrams are not negligible in these…

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the branching ratios of the Cabibbo-suppressed decay modes D0-->Pi-Pi+ and D0-->K-K+. We measured: Gamma(D0-->K-K+)/Gamma(D0-->Pi-Pi+) = 2.81 +/-…

We give a systematical study on the recently reported excited charm and charm-strange mesons with potential $1^-$ spin-parity, including the $D^*_{s1}(2700)^+$, $D^*_{s1}(2860)^+$, $D^*(2600)^0$, $D^*(2650)^0$, $D^*_1(2680)^0$ and…

The Cabibbo allowed non-leptonic $B$-decays in two hadrons are studied, within the factorization hypothesis, in the framework of Isgur and Wise theory for the matrix elements of the $\Delta B=-\Delta C=\pm 1$ weak currents. The $SU(2)_{HF}$…

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 calculate the contributions of penguin diagrams with internal u or c quarks to various inclusive charmless B-decay rates. Further we analyze the influence of the chromomagnetic dipole operator Q_8 on these rates. We find that the rates…

Although the two-body charmed decays $B_{(s)} \to \bar D_{(s)}^{(*)}P$ and $\bar D_{(s)}^{(*)}V$, where $P$($V$) denotes a light pseudoscalar(vector) meson, are CKM suppressed comparing with the $B_{(s)} \to D_{(s)}^{(*)}P$ and $…

Motivated by diquark exchange, we construct a class of extensions of the standard model. These models can generate large CP conserving and CP violating contributions to the doubly Cabbibo suppressed decays D^0\to K^+\pi^- without affecting…

Recent disagreement between experimental measurments of CP violating asymmetry in D -> K+ K- and D ->pi+ pi- and theoretical Standard model expectation motivated many studies within the Standard model and beyond. Rare charm decays offer new…

We have searched for flavor-changing neutral current decays and lepton-number-violating decays of D^+ and D^+_s mesons to final states of the form h^+- e^-+ e^+, where h is either \pi or K. We use the complete samples of CLEO-c open-charm…