Purpose The tracking and identification of charged particles are always essential for robust data analysis and comprehensive understanding of detector performance. As electrons and positrons constitute an important part of final state particles at BESIII, their tracking and identification efficiency should be investigated, which is useful for many experimental studies. Methods The efficiencies for electron and positron tracking and identification in the BESIII experiment are investigated with the radiative Bhabha process <InlineEquation ID="IEq1"> <EquationSource Format="TEX">$e^+e^-\rightarrow e^+e^-\gamma $</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msup> <mi>e</mi> <mo>+</mo> </msup> <msup> <mi>e</mi> <mo>-</mo> </msup> <mo stretchy="false">→</mo> <msup> <mi>e</mi> <mo>+</mo> </msup> <msup> <mi>e</mi> <mo>-</mo> </msup> <mi>γ</mi> </mrow> </math></EquationSource> </InlineEquation> from the data samples collected at the center-of-mass energies of 3.08 GeV and 3.097 GeV. The relative differences between data and MC associated with tracking and identification efficiencies of electrons and positrons, as well as the corresponding correction factors are determined here. Results The relative differences of tracking efficiency and particle identification efficiency after correction are mostly less than 0.5<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$\%$</EquationSource> <EquationSource Format="MATHML"><math> <mo>%</mo> </math></EquationSource> </InlineEquation> for transverse momenta <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$p_T>0.4$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <msub> <mi>p</mi> <mi>T</mi> </msub> <mo>></mo> <mn>0.4</mn> </mrow> </math></EquationSource> </InlineEquation> GeV and for the entire momentum region, respectively. Conclusion It is shown that the BESIII detector has good performance on the electron and positron detection and identification. This method and the two-dimensional distribution of <InlineEquation ID="IEq4"> <EquationSource Format="TEX">$p/p_T$</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mi>p</mi> <mo stretchy="false">/</mo> <msub> <mi>p</mi> <mi>T</mi> </msub> </mrow> </math></EquationSource> </InlineEquation> versus <InlineEquation ID="IEq5"> <EquationSource Format="TEX">$\cos \theta $</EquationSource> <EquationSource Format="MATHML"><math> <mrow> <mo>cos</mo> <mi>θ</mi> </mrow> </math></EquationSource> </InlineEquation> can be widely used in the systematic uncertainty studies for various experimental measurements.

Studies of the tracking and identification efficiencies of electrons and positrons at BESIII

期刊论文
发表日期：

2025年10月15日

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Xinyu Chai,
Mengzhen Wang,
Xiaobin Ji,
Shengsen Sun,
Dayong Wang

摘要

Purpose

The tracking and identification of charged particles are always essential for robust data analysis and comprehensive understanding of detector performance. As electrons and positrons constitute an important part of final state particles at BESIII, their tracking and identification efficiency should be investigated, which is useful for many experimental studies.

Methods

The efficiencies for electron and positron tracking and identification in the BESIII experiment are investigated with the radiative Bhabha process $e^+e^-\rightarrow e^+e^-\gamma $ $e^{+} e^{-} \to e^{+} e^{-} γ$ from the data samples collected at the center-of-mass energies of 3.08 GeV and 3.097 GeV. The relative differences between data and MC associated with tracking and identification efficiencies of electrons and positrons, as well as the corresponding correction factors are determined here.

Results

The relative differences of tracking efficiency and particle identification efficiency after correction are mostly less than 0.5 $\%$ $%$ for transverse momenta $p_T>0.4$ $p_{T} > 0.4$ GeV and for the entire momentum region, respectively.

Conclusion

It is shown that the BESIII detector has good performance on the electron and positron detection and identification. This method and the two-dimensional distribution of $p/p_T$ $p / p_{T}$ versus $\cos \theta $ $cos θ$ can be widely used in the systematic uncertainty studies for various experimental measurements.