We analyze the ππ production amplitudes in the excited Υ decay processes, Υ (2S) → Υ (1S)ππ, Υ (3S) → Υ (1S)ππ and Υ (3S) → Υ (2S)ππ, and the ππ and KK̄ production amplitudes in the charmonium decay processes, ψ(2S) → J/ψππ and J/ψ → φππ, φKK. The amplitudes are parametrized by the sum of Breit-Wigner amplitudes for the σ and the other relevant particles and of the direct 2π-production amplitude...

A qualitative and quantitative energetic and structural study of dibenzyl ketone (DBK) and benzyl ethyl ketone (BEK) was carried out in order to obtain insights into the type and magnitude of aromatic interactions that these systems present in their different phases. The crystal structure of DBK was obtained by X-ray crystallography, and it shows that the conformation adopted in the crystalline...

Reaction of the in situ deprotonated N-thiophosphorylated thiourea 2-MeO(O)CC6H4NHC(S)NHP(S)(OiPr)2 () with MCl2 (M = Zn(II), Cd(II)) in aqueous ethanol leads to complexes of the formula . Both compounds crystallise in the triclinic space group P1[combining macron] with Z = 2 and the metal cations are found in a tetrahedral S2S coordination environment formed by the C-S and P-S sulfur atoms. Th...

The experimental isoscalar ππ → ππ S-wave amplitude squared below 1.75 GeV is characterized by a very broad structure f0(4001200) with two narrow dips due to its destructive interference with the f0(980) and f0(1500). The f0(1370) and f0(1710) do not show up clearly in the ππ → ππ S-wave amplitude due to their weak coupling to ππ. This paper is about the controversial nature of the broad f0(400...

The experimental isoscalar ππ → ππ S-wave amplitude squared below 1.75 GeV is characterized by a very broad structure f0(4001200) with two narrow dips due to its destructive interference with the f0(980) and f0(1500). The f0(1370) and f0(1710) do not show up clearly in the ππ → ππ S-wave amplitude due to their weak coupling to ππ. This paper is about the controversial nature of the broad f0(400...

Properties of scalar–isoscalar mesons in a mass range from ππ threshold up to 1800 MeV are analysed using an unitary model with separable interactions in three decay channels: ππ , KK and an effective 2π2π. Different solutions are obtained by fitting ππ and KK data. Analytical structure of the meson-meson multichannel amplitudes is studied with a special emphasis on the important role played by...

Roy’s equations are used to check if scalar-isoscalar π − π amplitudes fitted to the “up-flat” and “down-flat” phase shift solutions fulfill crossing symmetry below 1 GeV. It is shown that the amplitude fitted to the “down-flat” solution satisfies crossing symmetry while the “up-flat” one does not. In such a way the “up-down” ambiguity in the scalar-isoscalar phase shifts is resolved in favour ...

A separable potential model of three coupled channels ππ, KK and an effective 2π2π has been constructed and applied in the analysis of the isoscalar S-wave ππ and KK phase shifts and inelasticities. A relatively narrow scalar resonance of mass 1400-1460 MeV has been found. This resonance is consistent with the recent CERN observation of an eventual scalar glueball at 1500 MeV. Other resonances ...

The ultraviolet behaviour of the generating functional for hadronic weak interactions with |∆S| = 1, 2 is investigated to one loop for a generic number of flavours and in the quenched approximation. New quenched chiral logarithms generated by the weak interactions can be accounted for via a redefinition of the weak mass term in the ∆S = ±1 weak effective Lagrangian at leading order. Finally, we...