Bonn 2001 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

T: Teilchenphysik

T 104: Feldtheorie 1

T 104.4: Vortrag

Montag, 26. März 2001, 17:00–17:15, HS III

Is the CKM matrix unitary? — •Hartmut Abele¹, Marga Astruc Hoffmann¹, Stefan Baessler¹, Dirk Dubbers², Michael Kreuz¹, Ulrich Mayer¹, Daniela Mund¹, Valery Nesvizhevsky², Uta Peschke¹, Jurgen Reich¹, Christian Vogel¹, and Oliver Zimmer² — ¹Physikalisches Institut, Univ. Heidelberg, Philosophenweg 12, 69120 Heidelberg — ²Institut Laue-Langevin, B.P. 156, 38042 Grenoble

An important aspect of the universality of the electroweak interaction is the unitarity condition of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. We have measured the beta-asymmetry in the decay of free polarized neutrons. Together with the world average of the neutron lifetime τ and the Fermi decay constant G_F, we derive the first element V_ud of the CKM matrix. In using this value from a baryon decay, the first element of the CKM matrix has been derived from particle physics alone.The unitarity check differs by more than three sigma standard deviation from unitarity. A measurement of the neutrino asymmetry in the decay of free neutrons is envisaged for this spring.