The effect of uu diquark suppression in proton splitting in Monte Carlo event generators

TL;DR

This paper investigates how reducing the assumed probability of (uu)-diquark formation in proton splitting within Monte Carlo event generators improves the semi-quantitative agreement with experimental data from NA49 at 158 GeV/c, using the Fritiof model in Geant4.

Contribution

It demonstrates that lowering the (uu)-diquark formation probability from 1/3 to 1/6 enhances the modeling of proton-proton reactions, aligning better with experimental observations.

Findings

Reduced (uu)-diquark probability improves data description

Semi-quantitative agreement with NA49 data achieved

Supports instanton model predictions

Abstract

Monte Carlo event generators assume that protons split into (uu)-diquarks and d-quarks with a probability of 1/3 in strong interactions. It is shown in this paper that using a value of 1/6 for the probability allows one to describe at a semi-quantitative level the NA49 Collaboration data for $p+p\rightarrow p+X$ reactions at 158 GeV/c. The Fritiof (FTF) model of Geant4 was used to simulate the reactions. The reduced weight of the (uu)-diquarks in protons is expected in the instanton model.