In the heavy-quark limit, the hadronic matrix elements entering nonleptonic B-meson decays into two light mesons can be calculated from first principles including " nonfactorizable " strong-interaction corrections. The B → πK, ππ decay amplitudes are computed including electroweak penguin contributions, SU(3) violation in the light-cone distribution amplitudes, and an estimate of power correcti...

We present photodissociation spectroscopy and computational analysis of three monocationic Cu-bipyridine complexes with one additional ligand of different interaction strength (N2, H2O and Cl) in the visible and UV. All three complexes show similar ππ* bands with origins slightly above 4 eV and vibrational band contours that are due to bipyridine ring deformation modes. Experiments at low tempe...

We properly define off-shell K → π transition amplitudes and use them to extract information for on-shell K → ππ amplitudes within Chiral Perturbation Theory. At order p2 in the chiral expansion all three parameters of weak interaction can be determined. At order p4 we are able to fix eleven additional constants out of thirteen contributing to off-shell K → π transitions, which leaves four unde...

We study the self-energy amplitudes for the ρ − ω meson system produced by an effective field theory model at the quark level characterized by a finite range quark-quark interaction and an isospin breaking bare quark mass difference m u − m d. Dynamical effects associated with confinement and dressing of quarks and the finite size of the produced ¯ qq meson modes are treated. Parameters of this...

The influence of strong π+π− interaction of the behaviour of pionium nS-state wave functions at small distance are investigated both analytically (perturbatively) and so numerically. It is shown that in the whole the accounting of strong interaction results in multiplying of pure Coulomb pionium wave functions by some function practically independent on value of principal quantum number n. Due ...

We prove that CP violating rate difference ∆(B̄0 → π+π−) = Γ(B̄0 → π+π−)− Γ(B0 → π−π+) is related to ∆(B̄0 → π+K−) = Γ(B̄0 → π+K−)− Γ(B0 → π−K+) in the three generation Standard Model. Neglecting small annihilation diagrams, and in the SU(3) symmetry limit, we show ∆(B̄0 → π+π−) = −∆(B̄0 → π+K−). The SU(3) breaking effects are estimated using factorization approximation, and yield ∆(B̄0 → π+π−) ≈ −(fπ...

Scalar-isoscalar mesons are studied using an unitary model in three channels: ππ, KK and an effective 2π2π. All the solutions, fitted to the ππ and KK data, exhibit a wide f0(500), a narrow f0(980) and two relatively narrow resonances, lying on different sheets between 1300 MeV and 1500 MeV. These latter states are similar to the f0(1370) and f0(1500) seen in experiments at CERN. Branching rati...

Strong isospin-breaking (IB) effects in CP-even and CP-odd K → ππ decays are computed to next-to-leading order (NLO) in the chiral expansion. The impact of these corrections on the magnitude of the ∆I = 1/2 Rule and on the size of the IB correction, ΩIB, to the gluonic penguin contribution to ǫ /ǫ are discussed. In the presence of IB, the standard isospin decomposition of the K → ππ, K → ππ, ππ...

Roy’s equations are used to check if the scalar-isoscalar ππ scattering amplitudes fitted to experimental data fulfill crossing symmetry conditions. It is shown that the amplitudes describing the “down-flat” phase shift solution satisfy crossing symmetry below 1 GeV while the amplitudes fitted to the “up-flat” data do not. In this way the long standing ”up-down” ambiguity in the phenomenologica...