Three-body baryonic $\overline B\to \Lambda\,\bar p\,\pi$ decays and such

C.-K. Chua; W.-S. Hou

doi:doi:10.1140/epjc/s2003-01203-8

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2023 Impact factor 4.2

Particles and Fields

Eur. Phys. J. C 29, 27-35 (2003)
DOI: 10.1140/epjc/s2003-01203

Three-body baryonic $\overline B\to \Lambda\,\bar p\,\pi$ decays and such

C.-K. Chua and W.-S. Hou

Department of Physics, National Taiwan University, Taipei, Taiwan 10764, China

(Received: 27 February 2003 / Published online: 5 May 2003 )

Abstract
We study the decay rates and spectra of $\overline B\to \Lambda\,\bar p\,\pi$ , $\Sigma^0\,\bar p\,\pi$ , $\Sigma^-\,\bar n\,\pi$ , $\Xi^0\,\overline \Sigma {}^+\,\pi$ , $\Xi^-\,\overline \Sigma {}^0\,\pi$ and $\Xi^-\,\overline \Lambda\,\pi$ modes in the factorization approach. The baryon pairs are produced through vector, axial vector, scalar and pseudoscalar operators. Previous predictions, including ours, are an order of magnitude too small compared to experiment. By incorporating QCD counting rules and studying the asymptotic behavior, we find an earlier relation between the pseudoscalar and axial vector form factors to be too restrictive. Instead, the pseudoscalar and scalar form factors are related asymptotically. Following this approach, the measured $\Lambda\,\bar p\,\pi^+$ rate ( $\sim 4.0 \times 10^{-6}$ ) and spectrum can be understood, and $\Lambda$ should be dominantly left-hand polarized, while we expect ${\cal B}(\Sigma^0\,\bar p\,\pi^+)\simeq 1.6\times 10^{-6}$ . These results and other predictions can be checked soon.