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.

Precision e- beam polarimetry at an e+e- B factory using tau-pair events

Li Y.;Finocchiaro G.;Banerjee S.;Cenci R.;Gaz A.;Marchiori G.;Batignani G.;Lusiani A.
Membro del Collaboration Group
;
Ferroni F.;
2023

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.
2023
Settore FIS/01 - Fisica Sperimentale
Beam techniques; Beam polarization; Beam control; Polarization in interactions & scattering; Particle phenomena; Particle interaction; Tau Leptons; Leptons; Lepton colliders; Particle accelerators
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11384/139388
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