A Bayesian analysis of pentaquark signals from CLAS data

TL;DR

This paper uses Bayesian analysis to reconcile conflicting CLAS experiment results on the pentaquark, showing the first lacked sufficient evidence and proposing a rigorous test for new particle detection.

Contribution

It introduces a Bayesian framework to analyze and compare experimental results, clarifying the evidence for the pentaquark and proposing a method for future particle searches.

Findings

The two CLAS experiments are compatible within Bayesian analysis.

The first experiment lacked sufficient information to confirm the pentaquark.

A new rigorous testing method for particle existence is proposed.

Abstract

We examine the results of two measurements by the CLAS collaboration, one of which claimed evidence for a $\Theta^{+}$ pentaquark, whilst the other found no such evidence. The unique feature of these two experiments was that they were performed with the same experimental setup. Using a Bayesian analysis we find that the results of the two experiments are in fact compatible with each other, but that the first measurement did not contain sufficient information to determine unambiguously the existence of a $\Theta^{+}$. Further, we suggest a means by which the existence of a new candidate particle can be tested in a rigorous manner.