We have searched with the KLOE detector for the P and CP violating decay η → ππ in a sample of 1.55 × 10 η’s from the decay φ → ηγ of φ-mesons produced in ee annihilations at DAΦNE. No signal is found. We obtain the upper limit BR(η → ππ)< 1.3×10 at 90% confidence level.

The goal of the DIRAC experiment at CERN (PS212) is to measure the ππ atom lifetime with 10% precision. Such a measurement would yield a precision of 5% on the value of the S-wave ππ scattering lengths combination |a0 − a2|. Based on part of the collected data we present a first result on the lifetime, τ = [

The goal of the DIRAC experiment at CERN (PS212) is to measure the ππ atom lifetime with 10% precision. Such a measurement would yield a precision of 5% on the value of the S-wave ππ scattering lengths combination |a0 − a2|. Based on part of the collected data we present a first result on the lifetime, τ = [

The excited state dynamics of resorcinol (1,3-dihydroxybenzene) following UV excitation at a range of pump wavelengths, 278 ≥ λ ≥ 255 nm, have been investigated using a combination of time-resolved velocity map ion imaging and ultrafast time-resolved ion yield measurements coupled with complementary ab initio calculations. After excitation to the 1(1)ππ* state we extract a timescale, τ1, for ex...

We review recent advances in the theory of strong-interaction effects and final-state interactions in hadronic weak decays of heavy mesons. In the heavy-quark limit, the amplitudes for most nonleptonic, two-body B decays can be calculated from first principles and expressed in terms of semileptonic form factors and lightcone distribution amplitudes. We summarize the main features of this novel ...

An overview is given of weak interaction physics of the light flavours. It starts with the definition of the CKM matrix and the measurement of its components in the light-flavour sector via semi-leptonic decays. The main part of the lectures is devoted to non-leptonic decays with a main emphasis on analytical calculations of K → ππ and K ↔ K0. It finishes with an overview of Chiral Perturbation...