Measurement of the cross section of $e^{+}e^{-}\to\eta\pi^{+}\pi^{-}$ at center-of-mass energies from 3.872 GeV to 4.700 GeV

TL;DR

This study measures the cross section of the process $e^{+}e^{-} o ext{eta} ext{pi}^+ ext{pi}^-$ across energies from 3.872 to 4.700 GeV, providing new data on this reaction with no observed resonance structures.

Contribution

First measurement of the cross section for $e^{+}e^{-} o ext{eta} ext{pi}^+ ext{pi}^-$ over this energy range using BESIII data.

Findings

Measured Born cross sections at 28 energy points.

No significant resonance structures observed.

First study of the intermediate process $e^{+}e^{-} o ext{eta} ho^{0}$.

Abstract

Using data samples with an integrated luminosity of 19 fb$^{-1}$ at twenty-eight center-of-mass energies from 3.872 GeV to 4.700 GeV collected with the BESIII detector at the BEPCII electron--positron collider, the process $e^{+}e^{-}\to\eta\pi^{+}\pi^{-}$ and the intermediate process $e^{+}e^{-}\to\eta\rho^{0}$ are studied for the first time. The Born cross sections are measured. No significant resonance structure is observed in the cross section lineshape.