We study QCD in 1+1 dimensions in the large Nc limit using light-front
Hamiltonian perturbation theory in the 1/Nc expansion. We use this formalism to
exactly compute hadronic transition matrix elements for arbitrary currents at
leading order in 1/Nc, which we use to write the semileptonic differential
decay rate of a heavy meson and its moments. We then compare with the results
obtained using an effective field theory approach based on perturbative
factorization, with the intention of better understanding quark-hadron duality.
A very good numerical agreement is obtained between the exact result and the
result using effective theories.Comment: Talk given at the High-Energy Physics International Conference on
Quantum Chromodynamics, 3-7 July (2006), Montpellier (France