XYZ spectroscopy at electron-hadron facilities II: Semi-inclusive processes with pion exchange

TL;DR

This paper extends a formalism to semi-inclusive processes at electron-hadron facilities, predicting cross sections for $XYZ$ hadrons via pion exchange and benchmarking with existing data, highlighting enhanced production near threshold.

Contribution

It introduces a new semi-inclusive formalism for $XYZ$ hadron production, including predictions and resonance contributions, expanding previous exclusive photoproduction models.

Findings

Predicted inclusive cross sections for charged $Z$ states via pion exchange.

Isolated $ ext{Delta}$ resonance contributions at small missing mass.

Near-threshold production is roughly doubled compared to exclusive reactions.

Abstract

Semi-inclusive processes are very promising to investigate $XYZ$ hadrons at the next generation of electron-hadron facilities, because they generally boast higher cross sections. We extend our formalism of exclusive photoproduction to semi-inclusive final states. The inclusive production cross sections for charged axial-vector $Z$ states from pion exchange are predicted. We isolate the contribution of $\Delta$ resonances at small missing mass. Production near threshold is shown to be enhanced roughly by a factor of two compared to the exclusive reaction. We benchmark the model with data of semi-inclusive $b_1^\pm$ production.