Spin-Momentum Correlations in Inclusive Semileptonic Decays of Polarized ${\Lambda }_b$ Baryons

Abstract

We consider spin-momentum correlations between the spin of the bottom baryon ${\Lambda }_{\mathrm{b}}$ and the momenta of its decay products in its inclusive semileptonic decay. We define several polar and azimuthal spin-momentum correlation measures in different event coordinate systems. The values of the spin-momentum correlation measures are calculated up to $\mathcal{O}(1/m_b^2)$ using the standard OPE und HQET methods. Some of the measures turn out to be sufficiently large to make them good candidates for a determination of the polarization of the ${\Lambda }_{\mathrm{b}}$ in e.g. $\mathrm{Z}$ decays.

Comments: 13 pages, 2 figures, more numerical results added; version published as Phys. Rev. D60, 014021 (1999)