22-28 July 2010
Palais des Congrès de Paris
Europe/Paris timezone

Tau lifetime and CP violation in tau decay at Belle

23 Jul 2010, 10:00
Salle 242A ()

Salle 242A

Parallel Session Talk 06 - CP violation, CKM and Rare Decays 06 - CP violation, CKM and Rare Decays


Mikhail Shapkin (IHEP)


The tau lepton lifetime is measured using the process e^+ e^- --> tau^+ tau^-, where both tau leptons decay to 3 pi nu. An upper limit on the relative lifetime difference between positive and negative tau-leptons is given. The obtained results are based on a large data sample collected on the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We also present the results of a search for CP violation in tau --> nu K_S pi. CP violation in semileptonic tau decays is generally forbidden in the Standard Model but can be induced by the exchange of an exotic scalar such as a charged Higgs in supersymmetric models. Exploiting the large statistics of the Belle data set, we report a model-independent limit for CP violation as well as a significantly improved measurement of the CP violation parameters for specific parameterizations of the hadronic structure functions.

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