Related papers: New Tensor Particles from pi -> e nu gamma and K -…
The present B -> pi K data is studied in the context of the standard model (SM) and with new physics (NP). We confirm that the SM has difficulties explaining the B -> pi K measurements. By adopting an effective-lagrangian parametrization of…
We find that the normal muon polarization in the decay K->mu nu_mu gamma is very sensitive to the values of the kaon vector F_V and axial-vector F_A form factors. It is shown that the ongoing KEK-E246 experiment can definitely determine the…
We complement studies of the neutral pion transition form factor pi^0 --> gamma^(*) gamma^(*) with calculations for the electromagnetic decay widths of the processes pi^0 --> e^+ e^-, pi^0 --> e^+ e^- gamma and pi^0 --> e^+ e^- e^+ e^-.…
We summarize the indirect effects of new physics in a variety of processes. We consider precision electroweak measurements, the $g-2$ of the muon, rare decays, meson mixing, CP violation, lepton number violating interactions, double beta…
The Standard Model of the electroweak and strong interactions of particle physics is a quantum field theory. Elementary particles are not indivisible `pieces' of matter but energy bundles of fields, whose properties and interactions are a…
The decay K- -> pi0 e- nu has been studied using in-flight decays detected with "ISTRA+" setup operating at the 25 GeV negative secondary beam of the U-70 PS. About 130K events were used for the analysis. The lambda_+ parameter of the…
A kaon decaying into three pions is an example of a weak process. However, since the quarks are confined into mesons, the strong interaction also plays an important part. The reaction is a low-energy one, meaning that it takes place in the…
The OKA Collaboration has obtained a new upper limit on the $K^+ \to \pi^0\pi^0\pi^0 e^+ \nu$ decay probability which is 65 times lower than the one currently listed by PDG. However it is still about $10^{4}$ times worse than the…
We analyze the supersymmetric contributions to direct-CP-violating observables in $K \to \pi\pi\gamma$ decays induced by gluino-mediated magnetic-penguin operators. We find that $\epsp_{+-\gamma}$ and the differential width asymmetry of…
We test the Principle of Equivalence for particles and antiparticles, using CPLEAR data on tagged K0 and K0bar decays into pi^+ pi^-. For the first time, we search for possible annual, monthly and diurnal modulations of the observables…
We summarize the theoretical virtues of the rare K -> pi nu nu-bar decays and emphasize the unique role of KL -> pi0 nu nu-bar in probing the nature of physics beyond the Standard Model, in particular concerning possible new sources of CP…
The pure lepton decay of the polarized muon is considered, accounting for a new tensor interaction which is outside of the Michel local interactions. This interaction leads to new energy distribution and polarization of the final charged…
Babar collaboration has reported an intriguing opposite sign in the integrated decay rate asymmetry $A_{cp}(\tau \rightarrow K_{S}\pi\nu_{\tau})$ than that of SM prediction from the known K0 - $\bar{K0}$ mixing. Babar's result deviate from…
Analysis of the isoscalar S- and D-waves of processes pi-pi-> pi-pi, K-Kbar, eta-eta is carried out aimed at studying the status and QCD nature of scalar and tensor mesons below 2 GeV and 2.3 GeV, respectively. Assignment of these mesons to…
The study of radiative phi decays into scalar mesons, with subsequent decay into pi pi gamma, constitutes an important topic at the electron-positron collider DAPHNE. The interference of the respective amplitude with the one for pi+ pi-…
We consider light new particles $\chi$ and $\phi$ that carry baryon and lepton numbers. If these particles are lighter than nucleons they lead to exotic decays such as $p\to \pi^+ \chi$ and $p\to e^+\phi$, not yet fully constrained by…
In this article we analyze the contribution from intermediate spin-0 and spin-2 resonances to the $\tau\to\nu \pi\pi\pi$ decay by means of a chiral invariant Lagrangian incorporating these mesons. In particular, we study the corresponding…
We review the state-of-the-art theoretical analyses of tau decays into a pair of mesons and a neutrino. The participant vector and scalar form factors, $f_{+}(s)$ and $f_{0}(s)$, are described in the frame of Chiral Perturbation Theory with…
This work demonstrates that once a large number of pion is condensed in a high-energy hadron collision, the gamma-ray spectrum from $\pi^0$ decay takes on a typical broken power-law shape, which has been documented in many astronomical…
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…