[en] The charge radius of the proton can be determined using two different kinds of experiments: the spectroscopy technique, measuring the hyperfine structure of hydrogen atoms, and the scattering technique, deducing the radius from elastic lepton scattering off a proton target. These two methods lead to quite different results, a discrepancy known as the “proton radius puzzle”. To shed light on this problem, we have proposed a novel method for the determination of spatial moments from densities expressed in the momentum space. This method provides a direct access not only to the second order moment, directly related to the proton radius, but to all moments of any real order larger than-3. The method is applied to the global analysis of proton electric form factor experimental data from Rosenbluth separation and low-Q² experiments, paying specific attention to the evaluation of the systematic errors. Within this analysis, the integer order moments of the proton charge density are evaluated, the moment of second order leading to a new determination of the proton charge radius. (author)

[en] We compute the decays B → D₀^* and B → D₂^* with finite masses for the b and c quarks. We first discuss the spectral properties of both the B meson as a function of its momentum and the D₀^* and D₂^* at rest. We compute the theoretical formulae leading to the decay amplitudes from the three-point and two-point correlators. We then compute the amplitudes at zero recoil of B → D₀^*, which turns out not to be vanishing contrary to what happens in the heavy quark limit. This opens the possibility to get better agreement with experiment. To improve the continuum limit we have added a set of data with smaller lattice spacing. The B → D₂^* vanishes at zero recoil and we show a convincing signal but only slightly more than 1 sigma from 0. In order to reach quantitatively significant results we plan to exploit fully smaller lattice spacings as well as another lattice regularisation. (orig.)

[en] We compute the decays B→D_0"∗ and B→D_2"∗ with finite masses for the b and c quarks. We first discuss the spectral properties of both the B meson as a function of its momentum and the D_0"∗ and D_2"∗ at rest. We compute the theoretical formulae leading to the decay amplitudes from the three-point and two-point correlators. We then compute the amplitudes at zero recoil of B→D_0"∗, which turns out not to be vanishing contrary to what happens in the heavy quark limit. This opens the possibility to get better agreement with experiment. To improve the continuum limit we have added a set of data with smaller lattice spacing. The B→D_2"∗ vanishes at zero recoil and we show a convincing signal but only slightly more than 1 sigma from 0. In order to reach quantitatively significant results we plan to exploit fully smaller lattice spacings as well as another lattice regularisation