PT Journal
AU LHCb Collaboration (Aaij, Rea
   Garcia Martin, LM
   Henry, L
   Jashal, BK
   Martinez-Vidal, F
   Oyanguren, A
   Remon Alepuz, C
   Ruiz Vidal, J
   Sanchez Mayordomo, C
TI Measurement of the electron reconstruction efficiency at LHCb
SO Journal of Instrumentation
JI J. Instrum.
PY 2019
BP P11023 - 20pp
VL 14
DI 10.1088/1748-0221/14/11/P11023
LA English
DE Pattern recognition; cluster finding; calibration and fitting methods; Performance of High Energy Physics Detectors
AB The single electron track-reconstruction efficiency is calibrated using a sample corresponding to 1.3 fb(-1) of pp collision data recorded with the LHCb detector in 2017. This measurement exploits B+ -> J/psi (e(+)e(-))K+ decays, where one of the electrons is fully reconstructed and paired with the kaon, while the other electron is reconstructed using only the information of the vertex detector. Despite this partial reconstruction, kinematic and geometric constraints allow the B meson mass to be reconstructed and the signal to be well separated from backgrounds. This in turn allows the electron reconstruction efficiency to be measured by matching the partial track segment found in the vertex detector to tracks found by LHCb's regular reconstruction algorithms. The agreement between data and simulation is evaluated, and corrections are derived for simulated electrons in bins of kinematics. These correction factors allow LHCb to measure branching fractions involving single electrons with a systematic uncertainty below 1%.
ER