Helicity form factors for D(s)→Alν process in the light-cone QCD sum rules approach

The helicity form factors of the D(s)-> Al+nu with A=a(1)(-), a(1)(0), b(1)(-),b(1)(0), K-1(1270) and K-1(1400) are calculated in the light-cone sum rules approach, up to twist-3 distribution amplitudes of the axial vector meson A. In the helicity form factors parametrization the unitarity constraints are applied to the fitting parameters. In addition, the effects of the low-lying resonances are included in series expansions of aforementioned form factors. The properties of the D-(s)-> Al+nu semileptonic decays are studied by extending the form factors to the whole physical region of q(2). For a better analysis, a comparison is also made between our results and the predictions obtained using transition form factors via LCSR, 3PSR and CLFQM methods.