Feasibility study of the measurement of Higgs pair creation at a photon linear collider

Abstract

We studied the feasibility of the measurement of Higgs pair creation at a Photon Linear Collider (PLC). From the sensitivity to the anomalous self-coupling of the Higgs boson, the optimum γγ collision energy was found to be around 270 GeV for a Higgs mass of 120 GeV/c 2 . We found that large backgrounds such as γγ → W + W − , ZZ, and b bb b, can be suppressed if correct assignment of tracks to parent partons is achieved and Higgs pair events can be observed with a statistical significance of ∼ 5σ by operating the PLC for 5 years.

Composite Higgs revealed in Higgs pair photo-production at future colliders

“…We have also given an estimate of the statistical sensitivity (S stat ) as given in [28], with L being the Luminosity. σ and σ SM are the cross section of the Higgs boson production in the CHMs and SM, while L, η, η BG , and σ BG are the integrated luminosity, the detection efficiency for the signal, the detection efficiency for backgrounds, and the cross section of background processes, respectively.…”

“…For the statistical sensitivity we have used an integrated luminosity of L = 2 ab −1 . The backgrounds used in the estimation are as given in [28] and used the cut efficiencies as estimated in table V of [28]. In estimating the statistical significance we have evaluated the cross-section (for signal and backgrounds) as a function of E γγ whereas the cut efficiencies as given in [28] are taken to be constant.…”

“…The possibility of measuring the triple Higgs coupling via the process γγ → hh has been widely discussed in the literature, as the sensitivity of this channel to the Higgs self-coupling is maximal at the threshold 2m h and greater than the sensitivities achieved directly at e + e − colliders in processes such as e + e − → Zhh and e + e − → ννhh in a wide range of center of mass energies [23,24]. The γγ → hh process [25] is loop mediated and goes through t and W ± loops, see for example [26][27][28] for details. In the SM these loops have destructive interference, resulting in small values of the cross-section, which reaches a maximum of roughly 0.5 fb.…”

“…In the SM these loops have destructive interference, resulting in small values of the cross-section, which reaches a maximum of roughly 0.5 fb. In BSM scenarios there can be a substantial change in the production crosssections as the cancellation between top quark and W boson loops can be spoilt [26][27][28]. Compared to other di-Higgs channels at tree level, e.g.…”

Impact of top-Higgs couplings on Di-Higgs production at future colliders

“…Recently, an extensive study of the feasibility of the diHiggs production with a parameter set of the ILC-based photon collider was reanalysed in ref. [102], which concluded that that the channel γγ → hh → bbbb process can be observed with a statistical significance of about 5σ for the integrated luminosity corresponding to 5 years running of the photon collider. Therefore, the photon collider provide an ideal place to study the new physics effect in the di-Higgs production.…”