CP violation and electric dipole moment at low energy τ-pair production

• DOI: 10.1016/j.nuclphysb.2004.08.038
• Publication Date: 2004-09-14T22:04:48Z
• Authors: J. Bernabéu; G.A. González-Spr...; J. Vidal
• Keywords: High Energy Physics - Phenomenology; High Energy Physics - Phenomenology (hep-ph); Violació CP (Física nuclear); 0103 physical sciences; FOS: Physical sciences; Física nuclear; 01 natural sciences

CP violation at low energy is investigated at the tau electromagnetic vertex. High statistics at B factories, and on top of the Upsilon resonances, allows a detailed investigation of CP-odd observables related to the tau-pair production. The contribution of the tau electric dipole moment is considered in detail. We perform an analysis independent from the high energy data by means of correlation and linear spin observables at low energy. We show that different CP-odd asymmetries, associated to the normal-transverse and normal-longitudinal correlation terms can be measured at low energy accelerators, both at resonant and non resonant energies. These observables allow to put stringent and independent bounds to the tau electric dipole moment that are competitive with other high or low energy results.<br/>18 pages, 2 figures, references added, minor changes in section 3 and 5, to be published in Nucl.Phys.B<br/>