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Constraints on top quark FCNC from electroweak precision measurements

F. Larios·R. Martinez·M. A. Perez
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Abstract

We study the one-loop contributions of the effective flavor changing neutral couplings (FCNC) tcZ and tcH on the electroweak precision observables Gamma_Z, R_c, R_b, R_l, A_c and A^FB_c. Using the known experimental limits on these observables, we may place 95% CL bounds on these FCNC couplings which in turn translate into the following limits for the branching ratios: BR(t -> cZ) < 6.7 10^-2 and BR(t -> cH) < (0.09 - 2.9) 10^-3 for 114 < m_H < 170 GeV.

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F. Larios, R. Martinez, M. A. Perez. 2005-01-20. Constraints on top quark FCNC from electroweak precision measurements. https://doi.org/10.1103/physrevd.72.057504

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