Precision Measurement of the Mass of the $\tau$ Lepton

Abstract

An energy scan near the $\tau$ pair production threshold has been performed using the BESIII detector. About $24$ pb${}^{-1}$ of data, distributed over four scan points, was collected. This analysis is based on $\tau$ pair decays to $ee$, $e\mu$, $eh$, $\mu \mu$, $\mu h$, $hh$, $e\rho$, $\mu \rho$ and $\pi \rho$ final states, where $h$ denotes a charged $\pi$ or $K$. The mass of the $\tau$ lepton is measured from a maximum likelihood fit to the $\tau$ pair production cross section data to be $m_{\tau }=(1776.91\pm 0.12_{-0.13}^{+0.10}$) MeV/$c^2$, which is currently the most precise value in a single measurement.

13 pages, 7 figures

References in corpus (2)

• Matching perturbative and Parton Shower corrections to Bhabha process at flavour factories
• Measurement of the mass of the $\tau$-lepton and an upper limit on the mass difference between ${\tau }^{+}$ and ${\tau }^{-}$

Cited by in corpus (7)

• STCF Conceptual Design Report: Volume 1 -- Physics & Detector
• The BESIII Physics Programme
• Prospects for ditauonium discovery at colliders
• Strategy to measure tau $g-2$ via photon fusion in LHC proton collisions
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• $\tau$ mass and $R$ value measurements at BES
• Generalised Known Kinematics (GKK) An Approach for Kinematic Observables in Pair Production Events with Decays Involving Invisible Particles