@article{513b0588e73449e4beb0a9f80b052623,
title = "Precision e− beam polarimetry at an e+e− B factory using tau-pair events",
abstract = "We present a new technique, {"}tau polarimetry,{"}for measuring the longitudinal beam polarization present in an e+e- collider through the analysis of e+e-→τ+τ- events. By exploiting the sensitivity of τ decay kinematics to the longitudinal polarization of the beams, we demonstrate that the longitudinal polarization can be measured with a 3 per mil systematic uncertainty at the interaction point using a technique that is independent of spin and beam transport modeling. Using 424.2±1.8 fb-1 of BABAR data at s=10.58 GeV, the average longitudinal polarization of the PEP-II e+e- collider has been measured to be ⟨P.",
author = "\{BABAR Collaboration\} and Lees, \{J. P.\} and V. Poireau and V. Tisserand and E. Grauges and A. Palano and G. Eigen and Brown, \{D. N.\} and Kolomensky, \{Yu G.\} and M. Fritsch and H. Koch and R. Cheaib and C. Hearty and Mattison, \{T. S.\} and McKenna, \{J. A.\} and So, \{R. Y.\} and Blinov, \{V. E.\} and Buzykaev, \{A. R.\} and Druzhinin, \{V. P.\} and Kozyrev, \{E. A.\} and Kravchenko, \{E. A.\} and Serednyakov, \{S. I.\} and Skovpen, \{Yu I.\} and Solodov, \{E. P.\} and Todyshev, \{K. Yu\} and Lankford, \{A. J.\} and B. Dey and Gary, \{J. W.\} and O. Long and Eisner, \{A. M.\} and Lockman, \{W. S.\} and \{Panduro Vazquez\}, W. and Chao, \{D. S.\} and Cheng, \{C. H.\} and B. Echenard and Flood, \{K. T.\} and Hitlin, \{D. G.\} and Y. Li and Lin, \{D. X.\} and S. Middleton and Miyashita, \{T. S.\} and P. Ongmongkolkul and J. Oyang and Porter, \{F. C.\} and M. R{\"o}hrken and Meadows, \{B. T.\} and Sokoloff, \{M. D.\} and Smith, \{J. G.\} and Wagner, \{S. R.\} and D. Bernard and Lange, \{D. J.\}",
note = "Publisher Copyright: {\textcopyright}=0.0035±0.0024stat±0.0029sys. The systematic uncertainty studies are described in detail, which can serve as a guide for future applications of tau polarimetry. A proposed e- beam longitudinal polarization upgrade to the SuperKEKB e+e- collider would benefit from this technique.",
year = "2023",
month = nov,
day = "1",
doi = "10.1103/PhysRevD.108.092001",
language = "English (US)",
volume = "108",
journal = "Physical Review D",
issn = "2470-0010",
publisher = "American Physical Society",
number = "9",
}