Related papers: Correlations between epsilon'/epsilon and Rare K D…
We analyze rare K and B decays in the Littlest Higgs (LH) model without T-parity. We find that the final result for the Z^0-penguin contribution contains a divergence that is generated by the one-loop radiative corrections to the currents…
We analyze the CP violating ratio epsilon'/epsilon and rare K and B decays in the MSSM with minimal flavour and CP violation, including NLO QCD corrections and imposing constraints on the supersymmetric parameters coming from epsilon,…
We analyze the rare kaon decays $K_L \to \pi^0 \nu \bar \nu$, $K^+ \to \pi^+ \nu \bar \nu$, $K_L \to \pi^0 e^+ e^-$ and $K_L \to \mu^+ \mu^-$ in conjunction with the CP violating ratio $\epsilon'/\epsilon$ in a general class of…
The non-minimal flavour violating interactions of mirror quarks and new heavy gauge bosons in the Littlest Higgs model with T-parity (LHT) give rise to naturally large CP-violating effects in the B_s system. In view of a large new CP phase…
The measured B -> pi pi, pi K branching ratios exhibit puzzling patterns. We point out that the B -> pi pi hierarchy can be nicely accommodated in the Standard Model (SM) through non-factorizable hadronic interference effects, whereas the B…
In certain new physics (NP) models, such as the Littlest Higgs model with T-parity, a strict correlation between the K_L -> pi0 nu anti-nu and K+ -> pi+ nu anti-nu branching ratios has been observed, allowing essentially only for two…
I give a detailed introduction into the theoretical formalism for epsilon'/epsilon, which measures direct CP-violation in K -> pi pi decays. The current status of hadronic matrix elements and the strange quark mass is discussed. Several…
During the last four years several parameters relevant for the analysis of the CP-violating ratio epsilon'/epsilon improved and/or changed significantly. In particular, the experimental value of epsilon'/epsilon and the strange quark mass…
We calculate the most interesting rare and CP-violating K and B decays in the Littlest Higgs model with T-parity. We give a collection of Feynman rules including v^2/f^2 contributions that are presented here for the first time and could…
With the first measurements of the branching ratios and the direct CP asymmetries of $B_s\to K^{-}K^{+}$, $K^{-}\pi^{+}$ decays by the CDF collaboration, we constrain the relevant parameter space of the Minimal Supersymmetric Standard Model…
Based on the low-energy effective Hamiltonian with the generalized factorization, we calculate the new physics contributions to branching ratios and CP-violating asymmetries of the charmless hadronic decays $B_s \to h_1 h_2$ in the standard…
The Standard-Model interpretation of the ratios of charged and neutral B-> pi K rates, R_c and R_n, respectively, points towards a puzzling picture. Since these observables are affected significantly by colour-allowed electroweak (EW)…
The real part of epsilon'/epsilon measures direct CP violation in the decays of the neutral kaons in two pions. It is a fundamental quantity which has justly attracted a great deal of theoretical as well as experimental work. Its…
The recent observation of B_d -> pi^0 pi^0 at the B factories with a surprisingly large branching ratio represents a challenge for theory, and complements the amazingly small B_d -> pi^+ pi^- rate. We point out that all puzzling B -> pi pi…
We present a systematic analysis of the angular distribution of Bbar -> Kbar^\ast (-> Kbar pi) l^+ l^- decays with l = e, mu in the low recoil region (i.e. at high dilepton invariant masses of the order of the mass of the b-quark) to…
We have studied the contribution of the high-scale SUSY to the K_L to pi^0 nu{bar nu} and K^+ to pi^+ nu{bar nu} processes correlating with the CP violating parameter epsilon_K. Taking account of the recent LHC results for the Higgs…
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…
The decays $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$, being the theoretically cleanest rare decays of mesons, are very sensitive probes of New Physics. In view of the excellent prospects of reaching the Standard Model sensitivity…
We analyse for the first time the CP violating ratio $\varepsilon'/\varepsilon$ in $K\to \pi\pi$ decays in leptoquark (LQ) models. Assuming a mass gap to the electroweak (EW) scale, the main mechanism for LQs to contribute to…
Using the recent first lattice results of the RBC-UKQCD collaboration for $K \to \pi\pi$ decays, we perform a phenomenological analysis of $\epsilon_K^{\prime}/\epsilon_K$ and find a discrepancy between SM prediction and experiments by…