Role of polarizations and spin-spin correlations of W's in e-e plus ?W-W plus at V=250 GeV to probe anomalous W-W plus Z=? couplings

We study anomalous W-W+Z=gamma couplings due to dimension-6 operators in the production process e-e+ -> W-W+ followed by semileptonic decay using polarizations and spin-spin correlations of W bosons. The construction of some of the polarization and spin-spin correlation asymmetries required one to distinguish between two decay quarks coming from W+ decay. We developed an artificial neural network and a boosted decision tree to distinguish down-type jets from up-type jets and used them to put constraints ffiffion anomalous couplings at the International Linear Collider (ILC) running at V = 250 GeV with s integrated luminosities of L is an element of {100 fb-1; 250 fb-1; 1000 fb-1; 3000 fb-1}. We find that the use of polarization and spin-correlation observables, on top of the cross sections, significantly improves the limits on anomalous coupling compared to the earlier studies.

Automated summary

We study anomalous W-W+Z = gamma couplings in the production process e-e+ -> W-W+ followed by semileptonic decay using polarizations and spin-spin correlations of W bosons. We develop an artificial neural network and a boosted decision tree to distinguish down-type jets from up-type jets and use them to put constraints on anomalous couplings at the International Linear Collider (ILC). Our findings show that the use of polarization and spin-correlation observables significantly improves the limits on anomalous coupling compared to earlier studies.