# Cluster properties from two-particle angular correlations in p+p collisions at $\sqrt{s}$ = 200 and 410 GeV

## TL;DR

This paper analyzes two-particle angular correlations in proton-proton collisions at 200 and 410 GeV, revealing complex structures and extracting cluster properties using a large-coverage detector, and comparing results with models and previous data.

## Contribution

It provides new measurements of cluster sizes and decay widths at different energies using the PHOBOS detector's extensive coverage, enhancing understanding of short-range correlations in proton-proton collisions.

## Key findings

- Complex two-dimensional correlation structures observed.
- Cluster sizes and decay widths extracted and compared.
- Results consistent with some models and previous experiments.

## Abstract

We present results on two-particle angular correlations in proton-proton collisions at center of mass energies of 200 and 410 GeV. The PHOBOS experiment at the Relativistic Heavy Ion Collider has a uniquely large coverage for charged particles, giving the opportunity to explore the correlations at both short- and long-range scales. At both energies, a complex two-dimensional correlation structure in $\Delta \eta$ and $\Delta \phi$ is observed. In the context of an independent cluster model of short-range correlations, the cluster size and its decay width are extracted from the two-particle pseudorapidity correlation function and compared with previous measurements in proton-proton and proton-antiproton collisions, as well as PYTHIA and HIJING predictions.