Abstract: The possible role of the triangle mechanism in the B- decay into D*(0)pi(-)pi(0)eta and D*(0)pi(-)pi(+)pi(-) is investigated. In this process, the triangle singularity appears from the decay of B- into D*K-0(-) K*(0) followed by the decay of K-*0 into pi(-) K+ and the fusion of the K+ K-, which forms the a(0)(980) or f(0)(980), which finally decay into pi(0)eta or pi(+)pi(-), respectively. The triangle mechanism from the (K) over bar * K (K) over bar loop generates a peak around 1420 MeV in the invariant mass of pi(-) a(0) or pi(-) f(0), and it gives sizable branching fractions, Br(B- -> D*(0)pi(-) a(0); a(0) -> pi(0)eta) = (1.66 +/- 0.45) x 10(-6) and Br(B- -> D*(0)pi(-) f(0); f(0) -> pi(+)pi(-)) = (2.82 +/- 0.75) x 10(-6).

Abstract: The masses of the D*(s0) (2317) and D-s1(2460) resonances lie below the DK and D* K thresholds respectively, which contradicts the predictions of naive quark models and points out to non-negligible effects of the D(*) K loops in the dynamics of the even-parity scalar (J(pi) = 0(+)) and axial-vector (J(pi) = 1(+)) c (s) over bar systems. Recent lattice QCD studies, incorporating the effects of the D(*) K channels, analyzed these spin-parity sectors and correctly described the D*(s0)(2317) – D-s1(2460) mass splitting. Motivated by such works, we study the structure of the D*(s0)(2317) and D-s1(2460) resonances in the framework of an effective field theory consistent with heavy quark spin symmetry, and that incorporates the interplay between D(*) K meson-meson degrees of freedom and bare P-wave c (s) over bar states predicted by constituent quark models. We extend the scheme to finite volumes and fit the strength of the coupling between both types of degrees of freedom to the available lattice levels, which we successfully describe. We finally estimate the size of the D(*) K two-meson components in the D*(s0)(2317) and D-s1(2460) resonances, and we conclude that these states have a predominantly hadronic-molecular structure, and that it should not be tried to accommodate these mesons within c (s) over bar constituent quark model patterns.

Abstract: Our way of describing Nature is based on local relativistic quantum field theories, and then CPT symmetry, a natural consequence of Lorentz invariance, locality and hermiticity of the Hamiltonian, is one of the few if not the only prediction that all of them share. Therefore, testing CPT invariance does not test a particular model but the whole paradigm. Current and future long baseline experiments will assess the status of CPT in the neutrino sector at an unprecedented level and thus its distinction from similar experimental signatures arising from non-standard interactions is imperative. Whether the whole paradigm is at stake or just the standard model of neutrinos crucially depends on that.