Measurements of Differential Cross Sections of Inclusive $\pi^0$ and $K^0_S$ Production in $e^{+}e^{-}$ Annihilation at Energies from 2.2324 to 3.6710 GeV

TL;DR

This study measures how often neutral pions and kaons are produced in electron-positron collisions at energies between 2.2 and 3.7 GeV, revealing deviations from theoretical predictions especially at lower energies.

Contribution

First measurements of inclusive $$ and $K^0_S$ differential cross sections at these energies, providing new data to test and refine fragmentation models.

Findings

Significant deviations from existing fragmentation function predictions at lower energies.

Differential cross sections measured across a broad hadron energy range.

Results highlight the need for improved theoretical models.

Abstract

Based on electron positron collision data collected with the BESIII detector operating at the BEPCII storage rings, the differential cross sections of inclusive $\pi^0$ and $K^0_S$ production as a function of hadron momentum, normalized by the total cross section of the $e^{+}e^{-} \to$ hadrons process, are measured at six center-of-mass energies from 2.2324 to 3.6710 GeV. Our results with a relative hadron energy coverage from 0.1 to 0.9 significantly deviate from several theoretical calculations based on existing fragmentation functions, especially at lower energies.