Bottom Baryon Decays to Pseudoscalar Meson and Pentaquark

TL;DR

This paper uses SU(3) flavor symmetry to analyze bottom baryon decays into pseudoscalar mesons and pentaquarks, providing decay rate estimates to guide experimental searches for these exotic states.

Contribution

It offers a decomposition of decay amplitudes based on flavor symmetry and estimates relative decay rates, highlighting promising channels for experimental detection of pentaquarks.

Findings

Decay rates for certain bottom baryon decays are comparable to known channels.

Internal and external W-emission diagrams are distinguished in decay processes.

Guidelines for experimental searches for bottom baryon pentaquarks are provided.

Abstract

Based on SU(3) flavor symmetry, we decompose the decay amplitudes of bottom baryon decays to a pseudoscalar meson and an octet (a decuplet) pentaquark in terms of three (two) invariant amplitudes $T_1$ and $T_{2,3}$ ($\tilde T_1$ and $\tilde T_2$) corresponding to external $W$-emission and internal $W$-emission diagrams, respectively. For antitriplet bottom baryons $\Lambda_b^0,\Xi_b^0$ and $\Xi_b^-$, their decays to a decuplet pentaquark proceed only through the internal $W$-emission diagram. Assuming the dominance from the external $W$-emission amplitudes, we present an estimate of the decay rates relative to $\Lambda_b^0\to P_p^+K^-$, where $P_p^+$ is the hidden-charm pentaquark with the same light quark content as the proton. Hence, our numerical results will provide a very useful guideline to the experimental search for pentaquarks in bottom baryon decays. For example, $\Xi_b^0\to P_{\Sigma^+}K^-$, $\Xi_b^-\to P_{\Sigma^-}\bar K^0$, $\Omega_b^-\to P_{\Xi^-}\bar K^0$ and $\Omega_b^-\to P_{\Xi^0}K^-$ may have rates comparable to that of $\Lambda_b^0\to P_p^+K^-$ and these modes should be given the higher priority in the experimental searches for pentaquarks.