Two-photon fusion Higgs production in collisions with proton and ion beams at the LHC, HE-LHC, and FCC

The production of the Higgs boson in ultraperipheral collisions (UPCs) of proton and nuclear beams at three future colliders — the high-luminosity Large Hadron Collider (HL-LHC), the high-energy LHC (HE-LHC), and the Future Circular Collider (FCC) — is studied. The cross sections for the process AA $\overset{\gamma\gamma}{\rightarrow}$(A)H(A), with the Higgs particle produced via two-photon fusion at midrapidity and the hadron(s) A surviving the interaction, are computed with MADGRAPH 5 extended with the corresponding coherent $\gamma$ fluxes for Pb-Pb, Xe-Xe, Kr-Kr, Ar-Ar, O-O, p-Pb, and p-p collisions over $\sqrt{S}$$_{NN}$ ≈ 3–100 TeV. Taking into account the expected luminosities for all colliding systems, the yields and significances for observing the Higgs boson in UPCs, on top of the $\gamma$$\gamma$ → b$\overline{b}$,c$\overline{c}$,q$\overline{q}$ continuum backgrounds, at the three future colliders are estimated.At HL-LHC and HE-LHC, the systems with larger Higgs significance are Ar-Ar(6.3TeV) and Kr-Kr(12.5 TeV) respectively. However, evidence for $\gamma$$\gamma$ → H production would require ×200 and ×30 times larger integrated luminosities at both machines. Factors of ten can be gained by running for a year, rather than the typical 1-month heavy-ion run at the LHC, but the process will likely remain unobserved unless a higher energy collider such as the FCC is built. In the latter machine, a 5$\sigma$ observation of $\gamma$$\gamma$ → H is warranted in just the first nominal Pb-Pb and p-Pb runs.