The Saga of $h_c$ and $h_b$ Search in Heavy Quarkonia

TL;DR

This paper reviews the experimental efforts and theoretical understanding of searching for the $h_c$ and $h_b$ states in heavy quarkonia, highlighting recent studies and their implications.

Contribution

It critically analyzes the progress and challenges in detecting the $h_c$ and $h_b$ states, integrating recent experimental data with theoretical insights.

Findings

Updated experimental status of $h_c$ and $h_b$ searches

Critical assessment of previous and recent experimental results

Insights into the theoretical understanding of heavy quarkonium states

Abstract

In this brief review, we examine carefully and critically the status of search for the $h_c$ [$\psi(1^1P_1)$] charmonium state and the $h_b$ [$\Upsilon(1^1P_1)$] bottonium state, initiated by the E760 experiment. Recent experimental studies at CLEO/BABAR/BELLE are examined in the light of new theoretical and phenomenological understanding.