gPhysics with tau leptons at HERAh

                                 Linus Lindfeld




Recent analyses at HERA deal with a tau lepton in the final state of ep-collisions.

At the ZEUS experiment, a search for events containing isolated tau leptons

and missing transverse momentum in addition to that due to the tau decay was performed.

The analysis, based on isolated tracks from hadronic tau decays

and the exploitation of the internal jet structure, yields 3 tau candidates

where $0.40^{+0.12}_{-0.13}$ are expected from Standard Model. With the H1 detector,

the production of high-$P_{T}$ isolated tau leptons was studied using typical one-prong hadronic tau decays

as identification. In addition, a search for tau lepton pairs in elastic photon-photon collisions was performed.

Furthermore, the tau lepton was studied in a search for new physics as a decay product

of a resonantly produced leptoquark violating the conservation of lepton flavor.