Related papers: Exploring scalar contributions with $K^+ \to \pi^+…

In a combined investigation of the $B\to K^{(*)}\ell^+\ell^-$ decays, constraints on the related couplings in family non-universal $Z^{\prime}$ models are derived. We find that within the allowed parameter space, the recently observed…

The rare kaon decays K_L -> pi^0 nu {bar nu}, K^+ -> pi^+ nu {bar nu}, K_L -> pi^0 e^+ e^- and K_L -> pi^0 mu^+ mu^- are theoretically very clean and, being strongly CKM suppressed, highly sensitive to New Physics (NP). Recent Flavour…

The $K^+ \to \pi^0 \pi^0 e^+ \nu$ ($K_{e4}^{00}$) decay has been measured with stopped positive kaons for a data sample of 216 events. A comparison of the observed spectra with a Monte Carlo simulation determined the $K_{e4}^{00}$ form…

In this decade one expects a very significant progress in measuring the branching ratios for several rare $K$ and $B$ decays, in particular for the decays $K^+\to\pi^+\nu\bar\nu$, $K_L\to\pi^0\nu\bar\nu$, $B_s\to\mu^+\mu^+$ and…

We review the current status of the field of rare kaon decays. The study of rare kaon decays has played a key role in the development of the standard model, and the field continues to have significant impact. The two areas of greatest…

The theoretical status of the rare K --> pi nu nu, KL --> pi0 l+ l- and KL --> mu+ mu- decays in the Standard Model is reviewed. Their sensitivity to New Physics and their discriminating power is also illustrated.

We consider the scalar form factor in $\tau \to K\pi \nu_\tau$ decays. It receives contributions both from the scalar resonance $K_0^*(1430)$ and from the scalar projection of off-shell vector resonances. We construct a model for the…

We review the present status of rare B decays, focusing on inclusive decay modes and their role in our search for new physics. We also briefly discuss direct CP violation in rare B decays and the rare kaon decays $K^+\to \pi^+\nu\bar{\nu}$…

We investigate the angular distributions of the rare B decay, $B \to K^* (\to K \pi) \ell^+ \ell^-$, in general supersymmetric extensions of the standard model. We consider the new physics contributions from the operators $O_{7,8,9,10}$ in…

We study the differential decay rate for the rare $\Lambda_b \to \Lambda (\to N \pi)\ell^+\ell^-$ transition, including a determination of the complete angular distribution, assuming unpolarized $\Lambda_b$ baryons. On the basis of a…

We present a brief overview of the recent theoretical progress to describe the K_{l2} and K_{l3} decays. We discuss the interesting probes of the Standard Model offered by these decays such as the extraction of |V_{us}| and the test of the…

A bound on the angle gamma of the unitarity triangle is derived using experimental information on the CP-averaged branching ratios for the rare decays B^+- -> pi^+- K^0 and B^+- -> pi^0 K^+-. The theoretical description is cleaner than the…

The flavor-changing neutral current process $b\to s l^+l^-$ is beneficial to testing the standard model and hunting for new physics scenarios. In exclusive decay modes like $B\to K^*(892)l^+l^-$, the S-wave effects may not be negligible and…

A Dalitz plot analysis of the OZI rule violating decay $D^+_s$ into $\pi^- \pi^+ \pi^+$ is presented using different partial wave approaches. Scalar and vector waves are described by $K$-matrices; their production is parameterized in a…

In the paper, we conduct a detailed investigation of the rare decay processes of charged meson, specifically $B^+ \to K^+\ell^+\ell^-$ with $\ell=(e,\mu,\tau)$ and $B^+ \to K^+\nu\bar{\nu}$. These processes involve…

We use QCD sum rules to calculate the hadronic matrix elements governing the rare decays $B \to K \ell^+ \ell^-$ and $B \to K^* \ell^+ \ell^-$ induced by the flavour changing neutral current $b \to s$ transition. We also study relations…

We study the rare decays $D^+\to \pi^{+}\ell^+\ell^-$, $D^+_s\to K^{+}\ell^+\ell^-$ and $D^0\to \ell^+\ell^-(\ell=e,\mu)$ in the minimal supersymmetic standard model with and without R-parity. Using the strong constraints on relevant…

In this article, we assume the two nonets of scalar mesons below and above 1 GeV are all $\bar{q}q$ states, and study the semi-leptonic decays $B\to S\ell^-\bar{\nu}_{\ell}$, $B\to S\ell^+\ell^-$ and $B\to S\bar{\nu}\nu$ both in the…

We update the Standard Model predictions for the rare decays $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$. In view of improved limits on $B_s$--$\bar B_s$ mixing we derive a stringent and theoretically clean Standard Model upper…

The decay K- -> pi0 e- nu has been studied using in-flight decays detected with the "ISTRA+" spectrometer working at the 25 GeV negative secondary beam of the U-70 PS. About 550K events were used for the analysis. The lambda+ parameter of…