arXiv subjects

G. A. González-Sprinberg

Publications and source records attributed to G. A. González-Sprinberg.

5 recordsLinked to original sources

arXiv2024

Electric and Magnetic Tau Dipole Moments Revisited

Precise measurements of magnetic and electric dipole moments are important tests of the Standard Model and beyond Standard Model physics, particularly for the electron and the muon. However, the situation presents distinctive challenges when dealing with the tau lepton due to its very short lifetime and relatively high mass. Here, we review the theoretical predictions and experimental measurements of both the anomalous magnetic and electric dipole moments of the tau lepton. Note: Contribution to the proceedings of the 17th International Workshop on Tau Lepton Physics, Louisville, USA, 4-8 December 2023

hep-ph↗

arXiv2007

$τ$ electric dipole moment with polarized beams

High luminosity Super B/Flavor factories, near and on top of the $Υ$ resonances, allow for a detailed investigation of CP-violation in $τ$ physics. In particular, bounds on the $τ$ electric dipole moment can be obtained from CP-odd observables. We perform an independent analysis from other low and high energy data. For polarized electron beam a CP-odd asymmetry, associated to the normal polarization term, can be used to set stringent bounds on the $τ$ electric dipole moment.

hep-ph↗

arXiv1995

WEAK DIPOLE MOMENTS AT ${\bf e^+e^-}$ COLLIDERS

The weak dipole moments of leptons and quarks, \ie those related to their $Z$--coupling, are reviewed. Standard Model predictions and experimental results may result in a stringent test for both their pointlike structure and also for the Standard Model. Special attention is devoted to the anomalous weak--magnetic dipole moment and to the $CP$--violating weak--electric dipole moment.

hep-ph↗

arXiv1995

$η-η^\prime$ Photoproduction and the Axial Isoscalar Neutral Current Coupling

We show that coherent $η$ and $\etap$ photoproduction by means of the Primakoff Effect on the proton depends on the strange component of the neutral axial current coupling. We construct polarization asymmetries that are sensitive to this coupling through the $γ- Z$ interference. The $η^\prime$ is not a Goldstone boson of a spontaneously broken chiral symmetry, but a phenomenological analysis of the $η$ and $η^\prime$ production through chiral perturbation theory allows to calculate the observables of interest. The polarized proton or polarized photon asymmetries are predicted to be close to $10^{-4}$ for $-q^2 \sim 0.1-0.5\;\mbox{\rm GeV}^2$.

hep-ph↗

arXiv1994

The tau weak-magnetic dipole moment

We calculate the prediction for the anomalous weak-magnetic form factor of the tau lepton at $q^2=M_Z^2$ within the Standard Model. With all particles on-shell, this is a electroweak gauge invariant quantity. Its value is $a_τ^w (M_Z^2)= - \;(2.10 + 0.61\, i) \times 10^{-6}$. We show that the transverse and normal components of the single-tau polarization of tau pairs produced at $e^+e^-$ unpolarized collisions are sensitive to the real and absorptive parts of the anomalous weak-magnetic dipole moment of the tau. The sensitivity one can achieve at LEP in the measurement of this dipole moment is discussed.

hep-ph↗