Partial waves of baryon-antibaryon in three-body B meson decay

The conspicuous threshold enhancement has been observed in the baryon-antibaryon subchannels of many three- body B decay modes. By examining the partial waves of baryon-antibaryon, we first show for B-+/- -> ppK(+/-) that the pK(+/-) angular correlation rules out dominance of a single pp partial wave for the pp enhancement, for instance, the resonance hypothesis or the strong final-state interaction in a single channel. The measured pK(+/-) angular correlation turns out to be opposite to the theoretical expectation of a simple short-distance picture. We study the origin of this reversed angular correlation in the context of the pp partial waves and argue that NN bound states may be the cause of this sign reversal. Dependence of the angular correlation on the pp invariant mass is important for probing the underlying issue from the experimental side.