Constraints on Z '-Boson Mass at ILC in the Absence of a Signal

Abstract

In this work, a technique for obtaining constraints on the $$Z{\kern 1pt} '$$ -boson mass is developed for the scenario of “ideal” agreement of the expected data with the Standard Model at future $${{e}^{ + }}{{e}^{ - }}$$ colliders. The methodology has been tested using statistical data simulation from the process $${{e}^{ + }}{{e}^{ - }} \to {{\mu }^{ + }}{{\mu }^{ - }}$$ at the ILC with 1 TeV center-of-mass energy and an integrated luminosity of 8 ab–1 using unpolarized electron and positron beams. The correctness of the data simulation is confirmed by comparing the obtained constraints with asymptotic ones. As a result of testing the methodology, quantitative estimates of the $$Z{\kern 1pt} '$$ -boson mass have been obtained for a wide range of models within the framework of which its existence is predicted. The presented data simulation scheme and the technique for obtaining constraints are the basis for subsequent accounting for systematics and analysis of the polarization observables.