Related papers: $B \to X_s \mu^+ \mu^-$ in Technicolor with Scalar…
The decay Bs to mu+ mu- is one of the milestones of the flavor program at the LHC. We reappraise its Standard Model prediction. First, by analyzing the theoretical rate in the light of its main parametric dependence, we highlight the…
The flavor-changing neutral current decay B_s->mu mu is highly suppressed in the standard model, but its branching fraction of 3.4*10^-9 could be significantly enhanced through contributions from new physics. At the LHC, this rare decay…
In the context of topcolor-assisted technicolor (TC2) models, we examine the flavor changing (FC) Z decay $Z\to b\bar{s}(\bar{b}s)$ and calculate the contributions of the new particles predicted by TC2 models to the branching ratio Br($Z\to…
We study the flavor-changing-neutral-current process c to u mu+ mu- using 1.3 fb^-1 of p p bar collisions at sqrt(s) = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We see clear indications of the Ds+ and…
We study flavor changing processes $\Upsilon \to B/{\bar B} X_s$ and $J/\psi \to D/{\bar D} X_u$ in the B factories and the Tau-Charm factories. In the standard model, these processes are predicted to be unobservable, so they serve as a…
Using newly available form factors obtained from light cone QCD sum rules in full theory, we study the flavor changing neutral current transition of $\Sigma_b \rar \Sigma \mu^+ \mu^-$ decay in the family non-universal $Z^\prime$ model. In…
We report on a search for the flavor-changing neutral current decays B^+ -> mu^+ mu^- K^+ and B^0 -> mu^+ mu^- K^{*0} using 88 pb^{-1} of data from p-pbar collisions at \sqrt{s}=1.8 TeV, collected with the Collider Detector at Fermilab.…
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 study extensions of the standard model with additional colored scalar fields which can couple directly to quarks. Natural suppression of flavor changing neutral currents implies minimal flavor violation, and fixes the scalars to…
The experimental measurements of flavor-changing neutral-current B-meson decays governed by b --> s + (gamma, l^+ l^-) transitions have entered a new level of precision. Recent results by Belle, CDF, Babar, and LHCb on B -->K^(*) l^+ l^-…
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 present a preliminary search for the flavor-changing neutral current decay B^+ -> K^+ nunubar using 56 million Y(4S) decays recorded with the BABAR detector at the SLAC B factory. Identification of the B^+ -> K^+ nunubar final state,…
We present a search for the flavor-changing neutral current decay B0_s -> phi mu+ mu- using about 0.45 fb^-1 of data collected in p \bar p collisions at sqrt{s} =1.96 TeV with the D{\O}detector at the Fermilab Tevatron Collider. We find an…
Some selected topics in flavour changing neutral current processes in $B$ decays are discussed in the context of the Standard Model. The emphasis here is on the determination of the CKM matrix elements from the ongoing and forthcoming…
We illustrate the possibility of observing signals from Flavor Changing Neutral Currents, originating from the scalar sector of a Two Higgs Doublet Model. In particular, we focus on the tree level process mu^+ mu^- --> tbar c + cbar t, via…
We study flavour-changing neutral current decays of the top quark in the democratic Three Higgs Doublet Model featuring a $Z_3$-symmetric scalar potential and Natural Flavour Conservation. In this framework, while such processes are absent…
We discuss the consequences of deviations from the Standard Model observed in $b\to s\mu^+\mu^-$ transitions for flavour-changing neutral-current processes involving down-type quarks and neutrinos. We work within an effective field theory…
We have searched for the flavor-changing neutral current decay b -> s mu+ mu- in p pbar collisions at sqrt(s) = 1.8 TeV with the DO detector at Fermilab. We determine the 90% confidence level limit for the branching fraction to be B(b ->…
We report the results of a search for the flavor-changing neutral-current decays $D^+\rightarrow \pi^+ \mu^+ \mu^-$ and $D^+\rightarrow \pi^+ e^+ e^-$ in data from Fermilab charm hadroproduction experiment E791. No signal above background…
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…