Anomalous quartic $WW\gamma\gamma$ couplings in $ep$ collisions at the LHeC and the FCC-he

TL;DR

This study investigates the sensitivity of future electron-proton colliders, LHeC and FCC-he, to anomalous quartic $WW\gamma\gamma$ couplings, providing more stringent, model-independent limits than current collider results.

Contribution

It presents the first detailed sensitivity analysis of $ep$ colliders for anomalous quartic $WW\gamma\gamma$ couplings using dimension-8 operators, improving existing bounds.

Findings

LHeC and FCC-he can set limits an order of magnitude more stringent than CMS.

The analysis covers energies of 60 and 140 GeV for electrons and 7-50 TeV for protons.

Results are competitive with other collider limits.

Abstract

We conducted a study on measuring $W^+W^-$ production and on the sensitivity limits at $95\%$ Confidence Level on thirteen anomalous couplings obtained by dimension-8 operators which are related to the anomalous quartic $WW\gamma\gamma$ couplings. We consider the main $e^-p \to e^-\gamma^*\gamma^*p \to e^-W^+W^-p$ reaction with the sub-process $\gamma^*\gamma^* \to W^+W^-$ at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). For the LHeC, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 7$ TeV. For the FCC-he, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 50$ TeV, respectively. It is interesting to notice that the LHeC and the FCC-he will lead to model-independent limits on the anomalous quartic $WW\gamma\gamma$ couplings which are one order of magnitude stringent than the CMS Collaboration limits, in addition to being competitive with other limits reported in the literature.