相关论文: New Tensor Particles from pi -> e nu gamma and K -…
Some discrepancies between theory and experiment in the B -> pi K decays suggest the possibility of a new physics contribution with the structure of an electroweak penguin amplitude. If such a scenario is realised in nature, the branching…
In models with large extra dimensions, where the fundamental gravity scale can be in the electroweak range, gravitational effects in particle physics may be noticeable even at relatively low energies. In this paper, we perform simple…
There is strong evidence that new physical degrees of freedom and new phenomena exist and may be revealed in future collider experiments. The best hints of what this new physics might be are provided by electroweak symmetry breaking. I…
Exploring hints of New Physics in the decay modes B -> pi K^* and B -> rho K can shed light on the B -> K pi puzzle. In this talk we discuss supersymmetric contributions to the direct CP asymmetries of the decays B -> pi K^* and B -> rho K…
The decays of narrow light vector mesons into pseudoscalar mesons and dileptons are calculated to leading order in a recently proposed scheme which treats pseudoscalar and vector mesons on equal footing. Since all required parameters have…
We report new experimental limits on the \pi^0 -> \gamma X decay of the neutral pion into a photon and a light boson X followed by the decay X -> e+e-. If this process exist, one would expect a flux of high energy X's produced from \pi^0's…
Corrections to $K\rightarrow\pi\pi\pi$ induced by vector and scalar meson exchange are investigated within chiral perturbation theory.
The decays $K \to \pi l^{+} l^{-}$, $K \to \pi \gamma \gamma $ and $K \to \pi \nu {\bar \nu}$ are investigated using the higher order terms of the chiral perturbation theory. The counterterms induced by strong, weak and electromagnetic…
We show that any new physics (NP) which affects B decays with penguin contributions can be absorbed by redefinitions of the standard-model (SM) diagrammatic amplitudes. Hence, there are no clean signals of NP in such decays unless there is…
Lie-type deformations provide a systematic way of generalising the symmetries of modern physics. Deforming the isometry group of Minkowski spacetime through the introduction of a minimal length scale $\ell$ leads to anti de Sitter spacetime…
Recent results from CLEO on $B\to K\pi$ indicate that the phase $\gamma$ may be substantially different from that obtained from other fit to the KM matrix elements in the Standard Model. We show that $\gamma$ extracted using $B\to K\pi,…
An overview is presented about old and recent methods to compute the $K\to \pi \pi$ decay amplitude.
In this letter we outline some reasons for considering a quantum field theory symmetric under quantum groups and we sketch some results obtained with collaborators in the k-Poincare framework. We deal with this latter as a toy model towards…
We advocate the idea that proton decay may probe physics at the Planck scale instead of the GUT scale. This is possible because supersymmetric theories have dimension-5 operators that can induce proton decay at dangerous rates, even with…
Penguin, or loop, decays of B mesons induce effective flavor-changing neutral currents, which are forbidden at tree level in the Standard Model. These decays give special insight into the CKM matrix and are sensitive to non-standard model…
The New Physics sensitivity of the s ---> d gamma transition and its accessibility through hadronic processes are thoroughly investigated. Firstly, the Standard Model predictions for the direct CP-violating observables in radiative K decays…
The electroweak properties of light and charmed D and Ds pseudoscalar mesons are investigated within a unified covariant constituent quark model. The quark-antiquark-meson vertices are assumed to have a symmetric form by the exchange of…
We provide a set of sum rules, using flavour symmetries, relating CP-averaged ratios and CP asymmetries of different neutral and charged B mesons decaying into an eta(') particle together with a pion, a kaon or a second eta('). These sume…
We analyse descriptions of electroweak symmetry breaking in terms of ultralocal antisymmetric tensor fields and gauge-singlet geometric variables, respectively; in particular, the Weinberg--Salam model and, ultimately, dynamical electroweak…
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…