Sum rules for leading and subleading form factors in Heavy Quark Effective Theory using the non-forward amplitude

F. Jugeau (1) , A. Le Yaouanc (1) , L. Oliver (1) , J. -C. Raynal (1)

1 LPT - Laboratoire de Physique Théorique d'Orsay [Orsay]

Within the OPE, we the new sum rules in Heavy Quark Effective Theory in the heavy quark limit and at order 1/m_Q, using the non-forward amplitude. In particular, we obtain new sum rules involving the elastic subleading form factors chi_i(w) (i = 1,2, 3) at order 1/m_Q that originate from the L_kin and L_mag perturbations of the Lagrangian. To the sum rules contribute only the same intermediate states (j^P, J^P) = ((1/2)^-, 1^-), ((3/2)^-, 1^-) that enter in the 1/m_Q^2 corrections of the axial form factor h_(A_1)(w) at zero recoil. This allows to obtain a lower bound on -delta_(1/m^2)^(A_1) in terms of the chi_i(w) and the shape of the elastic IW function xi(w). An important theoretical implication is that chi\'_1(1), chi_2(1) and chi\'_3(1) (chi_1(1) = chi_3(1) = 0 from Luke theorem) must vanish when the slope and the curvature attain their lowest values rho^2->3/4, sigma^2->15/16. These constraints should be taken into account in the exclusive determination of |V_(cb)|.

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

F. Jugeau, A. Le Yaouanc, L. Oliver, J. -C. Raynal. Sum rules for leading and subleading form factors in Heavy Quark Effective Theory using the non-forward amplitude. International Workshop on Quantum Chromodynamics : Theory and Experiment., Jun 2005, Conversano (Bari), Italy. pp.173. ⟨hal-00013441⟩