Soft and hard components of two-particle distributions on ($y_t,\eta ,\varphi$) from p-p collisions at $\sqrt{s}=200$ GeV

Abstract

We report measurements of large-scale two-particle correlations for 200 GeV p-p collisions on momentum components transverse rapidity $y_t$ (pion mass assigned), pseudorapidity $\eta$ and azimuth angle $\varphi$. In both transverse $y_t\otimes y_t$ and axial $(\eta \otimes \eta ,\varphi \otimes \varphi )$ two-particle subspaces we observe two components of correlation structure (soft and hard) which we interpret respectively in terms of longitudinal string fragmentation and transverse minimum-bias parton fragmentation (minijets). This combination is also represented by Lund-model-based Monte Carlo simulations such as Pythia.

Comments: 3 pages, 4 figures, Quark Matter 2004 poster writeup