Hadronic rescattering to solve helicity puzzle in $B^+\to p\bar p \pi^+(K^+)$ decays

TL;DR

This paper investigates how hadronic final state interactions can explain the opposite helicity angle distributions observed in certain B meson decays involving proton-antiproton pairs, providing a new interpretation of the helicity puzzle.

Contribution

It introduces a three-body final state interaction model that accounts for the helicity distribution differences in B+ decays, offering a novel explanation for the puzzle.

Findings

Model explains opposite helicity distributions qualitatively.

Linear dependence of distributions on cos θ_p is reproduced.

Elastic channel dominance below 2 GeV/c^2 is confirmed.

Abstract

We explore the contribution of hadronic final state interactions (FSI) to propose a production mechanism and interpret the puzzle on helicity angle distributions in $B^+\to p\bar p \pi^+$ and $B^+\to p\bar p K^+$ decays. Experimental results indicate opposite helicity angle $\theta_p$ distributions in those two channels with the difference presenting a remarkable linear dependence on $\cos \theta_p$. We assume the production mechanism is driven by $B^+\to xy\, m^+ \to p\bar p m^+$, where $m =\pi$ or $K$, and $xy$ represents favorable mesonic decay channels producing $p\bar p$. We develop a model that includes three-body final state interaction between the $p\,,~\bar p$ and $\pi^+$ or $K^+$ considering the dominance of elastic channels $\pi^+p$ and $K^+\bar p$ interactions below 2\,GeV/c$^2$. Our three-body framework with FSI explains qualitatively the observed opposite behavior of the helicity distributions and the observed linearity.