Testing factorization in B→D(*)X decays -: art. no. 014010

In QCD the amplitude for (B) over bar (0)-->D((*)+)pi(-) factorizes in the large N-c limit or in the large energy limit Q>>Lambda(QCD) where Q={m(b),m(c),m(b)-m(c)}. Data also suggest factorization in the exclusive processes B-->D(*)pi(+)pi(-)pi(-)pi(0) and B-->D(*)omegapi(-); however, by themselves neither a large N-c nor a large Q can account for this. We give exact large N-c relations among isospin amplitudes for (B) over bar -->(DX)-X-(*) and (B) over bar -->D-(*)(D) over bar X-(*), which can be used to test factorization through exclusive or inclusive measurements. Noting that the condition for large energy release in (B) over bar (0)-->D(+)pi(-) is enforced by the small velocity limit, m(b)>m(b)-m(c)>Lambda, we propose that the combined large N-c and SV limits justify factorization in B-->(DX)-X-(*). This combined limit is tested with the B-->(DX)-X-* inclusive decay spectrum measured by CLEO.