Helicity-flip bremsstrahlung and the measurement of {ital CP}-violating form factors in polarized {ital e}{sup +}{ital e}{sup {minus}} collisions
- Institut de Physique Theorique, Universite de Lausanne, CH 10105 Lausanne (Switzerland)
- Theory Group, Physical Research Laboratory, Navrangpura, Ahmedabad 380009 (India)
Certain momentum correlations in the production and subsequent decay of heavy fermion pairs in {ital e}{sup +}{ital e}{sup {minus}} collisions have increased sensitivity to {ital CP}-violating electric and ``weak`` dipole form factors of the fermion in the presence of longitudinal polarization of the {ital e}{sup +}{ital e}{sup {minus}} beams. However, unless the polarizations of {ital e}{sup +} and {ital e}{sup {minus}} are equal and opposite, collinear initial-state radiation accompanied by helicity flip results in a {ital CP}-invariant contribution to these and acts as a background, and must be calculated and subtracted in order to isolate the {ital CP}-violating contribution due to the dipole form factor. We calculate this background contribution to such correlations, to order {alpha}, in {ital e}{sup +}{ital e}{sup {minus}}{r_arrow}{tau}{sup +}{tau}{sup {minus}} and {ital e}{sup +}{ital e}{sup {minus}}{r_arrow}{ital t{bar t}}. For the anticipated luminosities at {tau}-charm factories and the SLC, for the {tau}, and at a future linear collider with a center-of-mass energy of 500 GeV for the top quark, these backgrounds are smaller than the statistical background and may be safely neglected.
- OSTI ID:
- 115921
- Journal Information:
- Physical Review, D, Vol. 52, Issue 5; Other Information: PBD: 1 Sep 1995
- Country of Publication:
- United States
- Language:
- English
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