Geometric genera for ample vector bundles with regular sections

Let X be a smooth complex projective variety of dimension n \geq 2. A notion of geometric genus p_g(X,E) for ample vector bundeles E of rank r < n on X admitting some regular sections is introduced. The following inequality holds: p_g(X,E) \geq h^{n-r,0}(X). The question of characterizing equalityis discussed and the answer is given for E decomposable of corank 2. Some conjectures suggested by the result are formulated.