The Photoproduction of the $b_1(1235)\pi$ System

TL;DR

This paper investigates the photoproduction reaction involving a proton and multiple pions at high energy, focusing on $ ho^{++}$ production and setting limits on $b_1(1235)$ resonance production.

Contribution

It provides the first measurement of the $ ho^{++}$ production cross section and sets upper limits on the production of the $b_1(1235)$ system in photon-proton interactions.

Findings

$ ho^{++}$ production cross section measured as $0.6\pm 0.1 ext{ μb}$

Upper limit established for $ o ext{reaction involving } ext{b}_1(1235)$

No significant resonance decaying to $b_1^\pm ext{pi}^\mp$ observed

Abstract

We report on a study of the reaction, $\gamma p \to p \pi^+\pi^+\pi^-\pi^-\pi^0$, at an incident photon energy of 19.3 GeV. The most significant feature of this reaction is $\Delta^{++}$ production which occurs with a cross section of $0.6\pm 0.1 \mu$b. An upper limit is set for the cross section for the reaction, $\gamma p \to \Delta^{++}b_1^-(1235)$, and a search is made for resonances decaying to $b_1^\pm\pi^\mp$.