Study of tau-pair production at HERA

TL;DR

This paper reports on the measurement of tau-pair production at HERA, comparing observed events with Standard Model predictions and finding good agreement across various distributions and invariant mass ranges.

Contribution

First detailed analysis of tau-pair production at HERA using ZEUS data, including cross section measurement and comparison with Standard Model expectations.

Findings

Measured tau-pair cross section aligns with Standard Model predictions.

Observed distributions match theoretical expectations, even at high invariant mass.

No significant deviation from the Standard Model was found.

Abstract

A study of events containing two tau leptons with high transverse momentum has been performed with the ZEUS detector at HERA, using a data sample corresponding to an integrated luminosity of 0.33 fb-1. The tau candidates were identified from their decays into electrons, muons or hadronic jets. The number of tau-pair candidates has been compared with the prediction from the Standard Model, where the largest contribution is expected from Bethe-Heitler processes. The total visible cross section was extracted.Standard Model expectations agree well with the measured distributions, also at high invariant mass of the tau pair.