The parton model approach to inclusive B meson decays

We test the parton model approach to inclusive B → γXs and B → eνXu processes by calculating a few moments of the distribution function. The 1/mQ expansion of the b-quark distribution function is discussed. We show that Petersonʹs fragmentation function is useful as the distribution function of b-quark but requires some improvements. By extension of Petersonʹs arguments, we obtain the refined form for the distribution function and with the refined function, we obtain the consistent results with the HQET.