Measurement of the -lepton mass with the Belle II experiment
Physical Review D, 2023•APS
We present a measurement of the τ-lepton mass using a sample of about 175 million e+ e-→
τ+ τ-events collected with the Belle II detector at the SuperKEKB e+ e-collider at a center-of-
mass energy of 10.579 GeV. This sample corresponds to an integrated luminosity of 190 fb-
1. We use the kinematic edge of the τ pseudomass distribution in the decay τ-→ π-π+ π-ν τ
and measure the τ mass to be 1777.09±0.08±0.11 MeV/c 2, where the first uncertainty is
statistical and the second systematic. This result is the most precise to date.
τ+ τ-events collected with the Belle II detector at the SuperKEKB e+ e-collider at a center-of-
mass energy of 10.579 GeV. This sample corresponds to an integrated luminosity of 190 fb-
1. We use the kinematic edge of the τ pseudomass distribution in the decay τ-→ π-π+ π-ν τ
and measure the τ mass to be 1777.09±0.08±0.11 MeV/c 2, where the first uncertainty is
statistical and the second systematic. This result is the most precise to date.
We present a measurement of the -lepton mass using a sample of about 175 million events collected with the Belle II detector at the SuperKEKB collider at a center-of-mass energy of 10.579 GeV. This sample corresponds to an integrated luminosity of . We use the kinematic edge of the pseudomass distribution in the decay and measure the mass to be , where the first uncertainty is statistical and the second systematic. This result is the most precise to date.
American Physical Society