Exploring anomalous $HZ\gamma $ couplings in $\gamma $-proton collisions at the LHC

TL;DR

This paper investigates the potential of the LHC to constrain anomalous $HZ\gamma$ couplings using photon-proton collisions, employing an effective Lagrangian with dimension six operators and analyzing various Higgs decay channels.

Contribution

It introduces a model-independent effective Lagrangian approach to study $HZ\gamma$ couplings in photon-proton collisions at the LHC, providing detailed numerical constraints and exploring the impact of increased luminosity.

Findings

Higgs photoproduction at the LHC can effectively probe $HZ\gamma$ couplings.

Constraints on anomalous couplings can be significantly improved with higher luminosity.

Multiple Higgs decay channels enhance the sensitivity to new physics.

Abstract

The $HZ\gamma $ coupling, which is highly sensitive to the new physics beyond the standard model, is studied through the process $pp\rightarrow p\gamma p\rightarrow pHX$ at the LHC. To this purpose, an effective Lagrangian, in a model independent approach, with dimension six operators is considered in this paper. New interaction terms regarding beyond the standard model physics include the Higgs boson anomalous vertices in both CP-even and CP-odd structures. A detailed numerical analysis is performed to scrutinize the accurate constraints on the effective $HZ\gamma $ couplings and to discuss how far the corresponding bounds can be improved. This is achieved by testing all the efficient Higgs decay channels and increasing the integrated luminosity at three different forward detector acceptance regions. The numerical results propose that the Higgs photoproduction at the LHC, as a complementary channel, has a great potential of exploring the $HZ\gamma $ couplings.