Non-perturbative effects in semi-leptonic Bc decays

الأصل · EN

We discuss the impact of the soft degrees of freedom inside the Bc meson on its rate in the semi-leptonic decay Bc -> X l nuₗ where X denotes light hadrons below the D⁰ threshold. In particular we identify contributions involving soft hadrons which are non-vanishing in the limit of massless leptons. These contributions become relevant for a measurement of the purely leptonic Bc decay rate, which due to helicity suppression involves a factor mₗ² and thus is much smaller than the contributions involving soft hadrons.