Measurement of $R_{\text{uds}}$ and $R$ between 3.12 and 3.72 GeV at the KEDR detector

TL;DR

This paper reports the most precise measurements to date of the ratio R and R_uds in the 3.12 to 3.72 GeV energy range using the KEDR detector, improving accuracy over previous results.

Contribution

First precise measurement of R and R_uds in the 3.12-3.72 GeV range using the KEDR detector, with systematic uncertainties around 2.1%.

Findings

Achieved about 3.3% accuracy at most energy points.

Provided the most accurate R(s) measurements in this energy range.

Systematic uncertainties were about 2.1%.

Abstract

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range.