Indication for $\pi^+ \pi^-$ scattering in $p+p$ collisions at $\sqrt{s_{_{NN}}} = $200 GeV

TL;DR

This paper reports a significant mass shift in the $ ho(770)^0$ meson observed in $p+p$ collisions at 200 GeV, indicating notable scattering interactions beyond phase space effects, with implications for understanding meson behavior in high-energy collisions.

Contribution

It demonstrates that the observed $ ho(770)^0$ mass shift cannot be explained by phase space alone, highlighting the role of scattering interactions in $p+p$ collisions at RHIC.

Findings

Measured a -40 MeV/$c^2$ mass shift of $ ho(770)^0$ at RHIC.

Phase space does not account for the mass shift observed.

Indicates significant scattering interactions in $p+p$ collisions.

Abstract

A $\rho(770)^0$ mass shift of about -40 MeV/$c^2$ was measured in $p+p$ collisions at $\sqrt{s_{_{NN}}} = $ 200 GeV at RHIC. Previous mass shifts have been observed at CERN-LEBC-EHS and CERN-LEP. We will show that phase space does not account for the $\rho(770)^0$ mass shift measured at RHIC, CERN-LEBC-EHS and CERN-LEP and conclude that there are significant scattering interactions in $p+p$ collisions.