Nonlinear Phenomena in Complex Systems, 2018, Vol.21, No.1, pp.21

NONLINEAR PHENOMENA IN COMPLEX SYSTEMS
An Interdisciplinary Journal

2018, Vol.21, No.1, pp.21 - 29

Model-Independent Constraints on Abelian Z' Couplings within the ATLAS Data on Dilepton Production Processes at √s = 13 TeV
A. O. Pevzner, V. V. Skalozub, A. V. Gulov, and A. A. Pankov

Study of lepton pair production is a powerful test of the Standard Model (SM) and can be used to search for phenomena beyond the SM. New heavy neutral bosons Z' decaying to charged lepton pairs l⁺l⁻ (l = e,μ) are predicted by many scenarios of new physics, including models with extended gauge sector. We estimate the LHC Z' discovery potential with Run 2 data comprised of 36.1 fb⁻¹ of pp collisions at √s = 13 TeV and recorded by ATLAS detector at the CERN LHC. The model-independent constraints on Z' fermion couplings were obtained for the first time for a selected set of Z' signal mass points of M_Z' = 2, 3, and 4 TeV by using the ATLAS data collected at the LHC. The analysis is based on the derived earlier special relations between the Z' couplings proper to the renormalizable theories. Taking into account the dependence of Z − Z' mixing angle θ₀ on Z' axial-vector coupling a, the limits on θ₀ are established as θ₀ < 10^{− 4} − 10^{− 3} in the investigated Z' mass range.

Key words: new gauge Z' bosons, dilepton resonances, Drell–Yan process, ATLAS experiment, Large Hadron Collider (LHC)

Full text: Acrobat PDF (816 KB)