Tau spin correlations and the anomalous magnetic moment

Abstract

We show that the precise determination of the Tau magnetic properties is possible in the next generation accelerators, specially at B/Flavour factories. We define spin correlation observables suitable to extract the real part of the magnetic form factor that, for the first time, will allow to test the standard model-QED predictions. In particular, the predicted QED-dependence with both the momentum transfer and the lepton mass can be precisely measured. Until now, the most stringent bounds on the $\tau$ magnetic moment $a_{\tau }$ come from LEP data with strong assumptions on the physics involved on the observed process. In this paper, we find three different combinations of spin correlations of the outgoing Taus that disentangle the magnetic moment form factor of the Tau lepton in the electromagnetic vertex. These combinations of asymmetries also get rid off the contributions coming from Z-mediating amplitudes to the defined correlations. Using unpolarized electron beams and an integrated luminosity of $15\times 10^{18}{b}^{-1}$, the sensitivity to the $\tau$ magnetic moment form factor is of the order $10^{-6}$. This sensitivity is two orders of magnitude better than the present existing high- or low-energy bounds on the magnetic moment and would allow its actual measurement with the precision of a few per cent.

14 pages, 1 figure

References in corpus (8)

• Theory of the tau lepton anomalous magnetic moment
• Tau anomalous magnetic moment form factor at Super B/Flavor factories
• Model independent bounds on the tau lepton electromagnetic and weak magnetic moments
• Tau Kinematics from Impact Parameters
• Spin asymmetries and correlations in lambda-pair production through the radiative return method
• CP violation and electric-dipole-moment at low energy $\tau$ production with polarized electrons
• TAU-PAIR PRODUCTION VIA PHOTON-PHOTON COLLISIONS AT LEP
• CP violation and electric-dipole-moment at low energy tau-pair production

Cited by in corpus (23)

• Precision Tau Physics
• Testing new physics with the electron g-2
• $\tau$ dipole moments via radiative leptonic $\tau$ decays
• Search for the Electric Dipole Moment and anomalous magnetic moment of the tau lepton at tau factories
• Towards testing the magnetic moment of the tau at one part per million
• Feasibility of tau lepton electromagnetic dipole moments measurement using bent crystal at the LHC
• $H\to {\tau }^{+}{\tau }^{-}\gamma$ as a Probe of the $\tau$ Magnetic Dipole Moment
• Towards a determination of the tau lepton dipole moments
• Constraining $\tau$-lepton dipole moments and gluon couplings at the LHC
• Model Independent Tests of the Hadronic Vacuum Polarization Contribution to the Muon $g$$-$$2$
• Unparticle-Induced Lepton Flavor Violating Decays τ^- ->l^- (V^0, ~P^0)
• LHC tau-pair production constraints on $a_{\tau }$ and $d_{\tau }$
• Collider and astrophysical signatures of light scalars with enhanced $\tau$ couplings
• Spin correlations and new physics in $\tau$-lepton decays at the LHC
• Probe of New Physics using Precision Measurement of the Electron Magnetic Moment
• Interference Resurrection of the $\tau$ Dipole through Quantum Tomography
• Spin correlations in $\tau$-lepton pair production due to anomalous magnetic and electric dipole moments
• Towards testing $(g-2{)}_{\tau }$ in $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}$: radiative corrections and projections for Belle II
• Constraints on $\tau$ electromagnetic moments via tau pair production at the Muon colliders
• Light new physics and the $\tau$ lepton dipole moments: prospects at Belle II
• Explaining the hints for lepton flavour universality violation with three $S_2$ leptoquark generations
• Electric and Magnetic Tau Dipole Moments Revisited
• Probing the Tau Anomalous Magnetic Moment at Colliders: From Ultra-Peripheral Collisions to the Precision Frontier