# The fusion of hard and soft Pomerons: 3-jet diffractive production

## TL;DR

This paper investigates the potential contamination of exclusive high-energy jet production signals by semi-exclusive processes involving Pomeron fusion, concluding that such contamination is negligible based on detailed QCD calculations.

## Contribution

It introduces the first analysis of semi-exclusive production via hard and soft Pomeron fusion in high-energy jet events, providing a detailed QCD color structure treatment.

## Key findings

- Semi-exclusive contamination is negligible.
- The study provides a detailed QCD color structure analysis.
- First consideration of Pomeron fusion in this context.

## Abstract

We consider the central exclusive production of high $E_T$ jets $pp\to p+(X+{\rm dijet})+p$. In particular we study the possible contamination of the purely exclusive signal by semi-exclusive production where no other secondaries are emitted in one hemisphere, between the highest $E_T$ dijet and the recoil proton, while in the other hemisphere a third jet, plus possibly additional hadron activity, is allowed, but still separated from the incoming proton by a large rapidity gap. This process arising from the fusion of a hard and a soft Pomeron has not been considered before. It turns out that it gives a negligible contribution. %contamination, which was not known before the calculation. The calculation involves a careful treatment of the QCD colour structure of the amplitudes.