相关论文: $K_L \to \pi^0 e^+ e^-$ and $B \to X_s \ell^+ \ell…
Flavor changing neutral current processes such as $b \to s \gamma$, $b \to s l^+ l^-$, $b \to s \nu \bar{\nu}$, $\epsilon_K$, $\Delta m_B$, $K^+ \to \pi^+ \nu \bar{\nu}$ and $\K_L \to \pi^0 \nu \bar{\nu}$ are calculated in the…
Rare flavour-changing neutral-current transitions of the type $s \to d \ell^+\ell^-(\nu\bar\nu)$ and $b \to s \ell^+\ell^-(\nu\bar\nu)$ are analysed in supersymmetric extensions of the Standard Model with generic flavour couplings. It is…
We analyze CP violation and Flavor Changing effects in a general Minimal Supersymmetric extension of the Standard Model with arbitrary non-universal soft-breaking terms. We show that, in this conditions, large FCNC effects are naturally…
In recent times, several discrepancies at the level of $(2-3)\sigma$ have been observed in the decay processes mediated by flavour changing neutral current (FCNC) transitions $b \to s \ell^+ \ell^-$, which may be considered as the…
Semileptonic B meson decays induced by $b \to s(d) l^+ l^-$ flavour changing neutral current (FCNC) transitions are very important to probe the quark-flavour sector of the standard model (SM) and also offer a probe to test new physics (NP).…
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…
Pure leptonic and semileptonic rare B decays, $B_s \to \mu^+ \mu^-$ and $B \to X_s \mu^+ \mu^-$ in the minimal supersymmetric Standard Model (MSSM), in particular, gluino and neutralino contributions to the decays, are discussed under Br($B…
Rare B meson decays mediated by flavour changing neutral current (FCNC) transition play interesting role to probe the flavour sector of the standard model (SM). Generally at the tree level, FCNC processes are not allowed in the SM but…
Recent experimental and theoretical progress regarding B --> K(*) l+ l- decays led to improved bounds on the Wilson coefficients C_9 and C_10 of four-fermion operators of the |Delta B|=|Delta S|=1 effective Hamiltonian. We analyze the…
Flavor changing neutral current $|\Delta B|=|\Delta S|=1$ processes are sensitive to possible new physics at the electroweak scale and beyond, providing detailed information about flavor, chirality and Lorentz structure. Recently the LHCb…
I give a pedagogical introduction into flavour-changing neutral current interactions of kaons and their role to reveal or constrain physics beyond the Standard Model (SM). Then I discuss the measure $\epsilon_K^\prime$ of direct CP…
We compute the flavor changing neutral current process $B \to X_s \mu^+ \mu^-$ in technicolor models with scalars. We find that the branching ratio can be enhanced relative to that of the Standard Model by as much as 60%. The full parameter…
We report a search for the flavor-changing neutral current decay $B \to K^{(*)} \ell^{+} \ell^{-}$ using a 29.1 fb${}^{-1}$ data sample accumulated at the $\Upsilon(4S)$ resonance with the Belle detector at the KEKB $e^{+}e^{-}$ storage…
We investigate 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, under generic assumptions concerning the…
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…
After briefly reviewing the status of epsilon'/epsilon in the Standard Model, I discuss SUSY contributions to epsilon'/epsilon, K^+ to pi^+ nu bar nu, K_L to pi^0 nu bar nu and K_L to pi^0 e^+ e^-. While in the simplest case of the MSSM…
We present measurements of the flavor-changing neutral current decays B --> Kl+l- and B --> K*l+l-, where l+l- is either an e+e- or mu+mu- pair. The data sample comprises 229 x 10^6 Y(4s) -->to BBbar decays collected with the BaBar detector…
We present an extensive analysis of rare K decays, in particular of the two neutrino modes K+->pi+ nu nu-bar and KL->pi0 nu nu-bar, in the Minimal Supersymmetric extension of the Standard Model. We analyse the expectations for the branching…
The ability of present and future experiments to test the Standard Model in the $B$ meson sector is described. We examine the loop effects of new interactions in flavor changing neutral current $B$ decays and in $Z\to b\bar b$,…
We present evidence for the flavor-changing neutral current decay $B\to K^*\ell^+\ell^-$ and a measurement of the branching fraction for the related process $B\to K\ell^+\ell^-$, where $\ell^+\ell^-$ is either an $e^+e^-$ or $\mu^+\mu^-$…