Anomalous gauge couplings of the Higgs boson at the LHC II: Study of additional backgrounds in semileptonic mode of WW scatterings

TL;DR

This paper investigates the potential to detect anomalous Higgs couplings at the LHC through semileptonic WW scattering, emphasizing the importance of background analysis and the capability to distinguish new physics effects.

Contribution

It extends previous work by analyzing additional backgrounds in semileptonic WW scattering to improve the measurement of anomalous Higgs couplings at the LHC.

Findings

Measurement of anomalous couplings feasible at 50 fb$^{-1}$ luminosity.

Higher luminosity allows separate determination of key anomalous coupling constants.

Background analysis enhances the reliability of detecting deviations from the Standard Model.

Abstract

Searching for the Higgs boson is of first priority in LHC experiments. Once a Higgs candidate is found, we then need to know whether it is the standard model (SM) Higgs boson or a Higgs boson in new physics beyond the SM. So far we do not know what model of new physics will actually reflect the property of the nature. A model-independent way of measuring the anomalous couplings of the Higgs boson will provide a no-lose study, i.e., if we find nonvanishing anomalous couplings (deviation from the SM couplings), we can conclude that it is a new physics effect. In a previous paper \cite{QKLZ09}, we gave a hadron level study of a model-independent test of the anomalous gauge couplings of the Higgs boson at the 14 TeV LHC via the semileptonic mode of weak-boson scatterings $pp\to W^+W^\pm j^f_1 j^f_2\to l^+\nu^{}_lj^{}_1j^{}_2j^f_1j^f_2$, and the conclusion is that, with certain kinematical cuts imposed, the measurement can start for an integrated luminosity of 50 fb$^{-1}$. For higher integrated luminosity, say 100 fb$^{-1}$, the two main anomalous coupling constants $f^{}_{WW}/\Lambda^2$ and $f^{}_W/\Lambda^2$ can be determined separately which may provide a clue for figuring out the underlying theory of new physics.