def METHOD_NAME(q2, par, B, V, l1, l2):
    GF = par['GF']
    ml1 = par['m_'+l1]
    ml2 = par['m_'+l2]
    scale = flavio.config['renormalization scale']['bvll']
    alphaem = flavio.physics.running.running.get_alpha(par, scale)['alpha_e']
    di_dj = flavio.physics.bdecays.common.meson_quark[(B,V)]
    xi_t = flavio.physics.ckm.xi('t',di_dj)(par)
    if q2 <= (ml1+ml2)**2:
        return 0
    return 4*GF/sqrt(2)*xi_t*alphaem/(4*pi)