# Tau Polarization in Tau-Neutrino Nucleon Scattering

Source: [Tau Polarization in Tau-Neutrino Nucleon Scattering](<https://www.sota2.com/research/paper/68fa26332c2a3760193b78d9>)

Collection index: [llms.txt](<https://www.sota2.com/research/llms.txt>)

Data updated: 2025-10-24T11:12:43.425Z

Authors: K. Hagiwara, K. Mawatari, H. Yokoya

Published: 2003-05-29T19:17:53.000Z

## Abstract

We investigate the spin polarization of \\tau^{\\pm} leptons produced in \\nu\_{\\tau} and \\bar{\\nu}\_{\\tau} nucleon scattering via charged currents. Quasi-elastic scattering, \\Delta resonance production and deep inelastic scattering processes are studied. The polarization information is essential for measuring the \\tau^{\\pm} appearance rate in long baseline neutrino oscillation experiments, because the decay particle distributions depend crucially on the \\tau^{\\pm} spin. In this article, we calculate the spin density matrix of each process and estimate the spin polarization vector in medium and high neutrino energy interactions. We find that the produced \\tau^{\\pm}'s have high degree of polarization, and their spin direction depends non-trivially on the energy and the scattering angle of \\tau^{\\pm} in the laboratory frame.

## Recorded benchmark results

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## Original sources and implementation

[Original paper](<https://arxiv.org/abs/hep-ph/0305324>)

[PDF](<https://arxiv.org/pdf/hep-ph/0305324.pdf>)