Related papers: Charm Changing Neutral Currents and Supersymmetry
We examine the prospects for observing weak flavour-changing neutral current (FCNC) decays of \B\ mesons at hadron colliders, including effects of anomalous $WWZ$~vertices. Since it is very difficult to measure the inclusive rate $B…
Direct CP violation beyond the standard model can be produced in charged D decays to final states with a $K_S$ by small new physics contributions to the transitions $D^+ \to K^o X^+$, where $X^+$ denotes any positively charged hadronic…
We discuss prospects for detecting the two charm-related phenomena of $D^0$-${\bar D}^0$ mixing and weak radiative decays of $D$ mesons ({\it e.g.} $D\to K^* + \gamma$). A general update of particle-antiparticle mixing for the pseudoscalar…
The problem of possible deviations from the Standard Model is considered in the framework of a variant of dynamical electroweak symmetry breaking. It comes clear, that the parameters of the theory, being obtained earlier and describing…
We present standard model (SM) estimates for exclusive $c \to u \gamma$ processes in heavy quark and hybrid frameworks. Measured branching ratios ${\cal{B}}(D^0 \to (\phi, \bar K^{*0}) \gamma)$ are at or somewhat exceeding the upper range…
We identify two Cabibbo suppressed $D^+$ decay modes with anomalously high branching ratios which are not simply explained by any model. All standard model diagrams that can contribute to these decays are related by symmetries to diagrams…
CP violating effects in the single top quark production via flavour changing neutral current (FCNC) reactions $e^+e^- ->t bar{q}$ and $e^+e^- ->bar{t}q$ (here $q$ refers to charm and up quarks) are studied. The effective Lagrangian…
Grand unified theories open the possibility to transfer the neutrino mixing matrix U_PMNS to the quark sector. This is accomplished in a controlled way in a supersymmetric grand-unified model proposed by Chang, Masiero and Murayama (CMM…
Recent CLEO results on neutral charm meson decays presented at the XXXVIth Rencontres de Moriond are discussed. We find no evidence of CP asymmetry in five different two-body decay modes of the D0 to pairs of light pseudo-scalar mesons. We…
Using 13.8 fb^{-1} of data collected at or just below the \Upsilon(4S) with the CLEO detector, we report the result of a search for the flavor changing neutral current process D^{0} \to \gamma\gamma. We observe no significant signal for…
We investigate a family-nonuniversal Abelian extension of hypercharge, which significantly alters the phenomenological features of the standard model. Anomaly cancellation requires that the third quark family transforms differently from the…
We report the first observation of the baryonic flavor-changing neutral current decay Lambda_b -> Lambda mu+ mu- with 24 signal events and a statistical significance of 5.8 Gaussian standard deviations. This measurement uses ppbar…
We analyze a new class of FCNC processes, the $f \to f^{\prime} \, \bar{\gamma}$ decays of a fermion $f$ into a lighter (same-charge) fermion $f^{\prime}$ plus a {\it massless} neutral vector boson, a {\it dark photon} $\bar{\gamma}$. A…
We report a search for non-Standard Model physics through the measurement of CP-violating asymmetry in the Cabibbo suppressed D0->pi+pi- and D0->K+K- decays reconstructed in about 5.94/fb of CDF data. We use the strong D*+->D0pi+ decay ("D*…
We investigate the possibility that scalar leptoquarks generate consequential effects on the flavor-changing neutral-current decays of charmed hadrons into final states with missing energy ($\not\!\!E$) carried away by either standard model…
These two lectures constitute a reappraisal and an update of the status of the Flavour Changing Neutral Current (FCNC) and CP violation issues in supersymmetry. The first lecture discusses these points in the framework of the Minimal…
We show that in the minimal 3-3-1 model the flavor changing neutral currents (FCNCs) do not impose necessarily strong constraints on the mass of the $Z^\prime$ of the model if we also consider the neutral scalar contributions to such…
We present a search for flavor changing neutral currents in decays of top quarks. The analysis is based on a search for ttbar -> l'null + jets (l, l' = e, mu) final states using 4.1 fb^-1 of integrated luminosity of ppbar collisions at…
In models with partially composite quarks, the couplings of quarks to the Z boson generically receive non-universal corrections that are not only constrained by electroweak precision tests but also lead to flavour-changing neutral currents…
We review some recent developments in charm meson physics. In particular, we discuss theoretical predictions and experimental measurements of charmed meson decays to leptonic, semileptonic, and hadronic final states and implications of such…