Using data collected by the high energy photoproduction experiment FOCUS at Fermilab we study the doubly and singly Cabibbo suppressed decays D and D s → K ππ. Our measurements of Γ(D → Kππ)/Γ(D → Kππ) = 0.0065 ± 0.0008 ± 0.0004 and Γ(D s → K ππ)/ Γ(D s → K Kπ) = 0.127 ± 0.007± 0.014 are based on samples of 189± 24 D and 567± 31 D s reconstructed events, respectively. We also present Dalitz plo...

The reversal of aromaticity and antiaromaticity upon excitation to the lowest ππ* state impacts on photophysics photoreactivity various annulenes. This unifying principle can guide rationalization a plethora excited-state reactions has strong predictive power in design new photochemical transformations. For more details, see Review by H. Ottosson et al. (DOI: 10.1002/chem.202203748)

It is well known that one can use B → ππ decays to probe the CP-violating phase α. In this paper we show that these same decays can be used to search for new physics. This is done by comparing two weak phases which are equal in the standard model: the phase of the t-quark contribution to the b → d penguin amplitude, and the phase of B d–B 0 d mixing. In order to make such a comparison, we requi...

We perform a detailed Regge analysis of NN , πN , KN , ππ and πK scattering. From it, we find expressions that represent the ππ scattering amplitudes with an accuracy of a few percent, for exchange of isospin zero, and ∼ 15% for exchange of isospin 1, and this for energies s > 1.4GeV and for momentum transfers |t| < ∼ 0.4GeV. These Regge formulas are perfectly compatible with the low energy (s ...

The leading twist parametrization of dipion mass distribution in hard exclusive reactions is proposed. Its parameters are related to quark distributions (usual and skewed) in the pion and to distributions amplitudes of mesons (π, ρ, etc.). We show that measurements of the shape of dipion mass distribution in hard exclusie reactions can give important information about partonic structure of the ...

The present theoretical status of the parameter for direct CP violation ε/ε in the Standard Model is reviewed and compared with most recent experimental measurements of the same quantity. After collecting the basic expressions for ε/ε, the situation of hadronic matrix element calculations is summarised. The matrix elements constitute the dominant source of uncertainty for theoretical determinat...