Measuring the anomalous quartic gauge couplings in the $W^+W^-\to W^+W^-$ process at muon collider using artificial neural networks

Abstract

The muon collider provides a unique opportunity to study the vector boson scattering processes and dimension-8 operators contributing to anomalous quartic gauge couplings. Because of the cleaner final state, it is easier to decode subprocess and certain operator couplings at a muon collider. We attempt to identify the anomalous W W W W coupling in W W → W W scattering in this paper. The vector boson scattering process corresponding to the anomalous W W W W coupling is µ + µ − → νν ν ν + − , with four (anti-)neutrinos in the final state, which pose difficulties for phenomenological studies. In this paper, the machine learning method is used to tackle this problem. We find that, the artificial neural network can be used to extract the W + W − → W + W − contribution, and is useful to reconstruct the center of mass energy of the subprocess which is important in the study of the Standard Model effective field theory. The sensitivities and the expected constraints on the dimension-8 operators at the muon collider with √ s = 30 TeV are presented. The artificial neural networks exhibit great potential in the phenomenological study of processes with multiple neutrinos in the final state.

Tri-photon at muon collider: a new process to probe the anomalous quartic gauge couplings

“…The upper limits from the W W νν channel are 0.0030 TeV −4 and 0.0046 TeV −4 for √ s TeV and L = 4 ab −1 [81], which are stronger than our √ s TeV case but less stringent than those for √ s = 10 TeV. For O T 6,7 operators, the expected constraints at √ s TeV and L = 1 ab −1 are 0.0261 TeV −4 and 0.0398 TeV −4 which are competitive to 0.033 TeV −4 and 0.038 TeV −4 from W + W − µ + µ − channel at √ s TeV and L = 4 ab −1 .At √ s = 30 TeV, our expected constraints on O T i are comparable with the results by extracting the W W W W aQGC using artificial neural networks[82].…”

“…For the muon collider with √ s = 3 TeV and L = 1 ab −1 , the expected constraints at S stat = 2 are about two orders of magnitude stronger than those at the √ s = 13 They studied the W W νν and W W µµ final states with the W bosons' hadronic decay. We also attempted to measure the aQGCs in W + W − → W + W − scattering at muon collider using artificial neural networks [82]. In principle, the tri-photon channel can only be used to constrain O T i operators, whereas O M i ,S i operators can be studied in these VBS W + W − production modes.…”