2021 Impact factor 4.991
Particles and Fields
Eur. Phys. J. C 8, 393-401
DOI 10.1007/s100529901082

Measurement of helicity parameters in top quark decay

Ch.A. Nelson - A.M. Cohen

Department of Physics, State University of New York at Binghamton, Binghamton, NY 13902-6016, USA

Received: 12 November 1998 / Published online: 27 April 1999

It is important to be able to quantitatively assay future measurements of competing observables consistent with the gV-A coupling predictions for $t
\rightarrow W^+ b $ decay, so plots of the values of these helicity parameters are given in terms of a " (V- A) + Additional Lorentz Structure". Three phase-type ambiguities are shown to exist, but measurement of the sign of the large interference between the W longitudinal/transverse amplitudes will resolve two of them. The large mb effects in both bL and bR amplitudes from some couplings demonstrate that it is less model dependent to measure helicity parameters, instead of setting limits on some arbitrary subset of coupling constants.

Author for correspondance: cnelson@bingvmb.cc.binghamton.edu

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