1999/08/13 by Hsien-Hung Shih, Shih, Hsien-Hung, Shih-Chang Lee +3
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #hep-ph
paper · pdf · doi:10.48550/arxiv.hep-ph/9908346
9 pages in Latex file, some comments and one table added
arxiv created 2000/06/03 · arxiv updated 2009/11/30
We study the polarized Λb baryon semileptonic decay Λb → Λclν using perturbative QCD factorization theorem. In this approach heavy baryon transition form factors are expressed as the convolutions of hard b quark decay amplitudes with universal Λb and Λc baryon wave functions. With the heavy baryon wave functions determined in our previous work, we predict the asymmetry parameter α( e)≡ (N+-N-)/(N++N-)=-0.31 \bf P⋅ e, where \bf P is the Λb baryon polarization, e a unit vector perpendicular to the Λb baryon momentum, N+ (N-) the number of leptons whose momenta possess positive (negative) components along e. This result is useful for extracting the transverse polarization of a Λb baryon from data of exclusive semileptonic decays.