Polarization and distribution function of the Lambda(b) baryon

Abstract

The polarization of the Lambda(b) baryon has been measured in ALEPH, OPAL, and DELPHI experiments. A significant loss on the transfer of the b quark polarization to the Lambda(b) baryon polarization has been noticed. This implies that the hadronization effects cannot be neglected. Therefore we may make use of the polarization measurements to look for a suitable model for the Lambda(b) distribution function. To investigate the Lambda(b) polarization, we construct four models based on a perturbative QCD factorization formula. The models are the quark model, the modified quark model, the parton model, and the modified parton model. The modified models mean the models having transverse degrees of freedom and the associated soft radiative corrections having been resummed. The quark and parton models cannot describe all experiments at the same time. On the other hand, the modified models can have the power to explain all data in the same formalism.