High precision higgs from high energy muon colliders

Abstract

Muon colliders are an exciting possibility for reaching the highest energies possible on the shortest timescale. They potentially combine the greatest strengths of e+e− and pp colliders by bridging the energy versus precision dichotomy. In this paper we study the sensitivity of Higgs properties that can be achieved with a future 3 or 10 TeV muon collider from single Higgs production. The results presented here represent the first comprehensive picture for the precision achievable including backgrounds and using fast detector simulation with Delphes. Additionally, we compare the results of fast detector simulation with available full simulation studies that include the muon collider specific Beam Induced Background, and show the results are largely unchanged. We comment on some of the strengths and weaknesses of a high energy muon collider for Higgs physics alone, and demonstrate the complementarity of such a collider with the LHC and e+e− Higgs factories. Furthermore, we discuss some of the exciting avenues for improving future results from both theoretical and detector R&D that could be undertaken.

Towards a Muon Collider

“…While realistic enough for a first quantitative assessment of the Higgs couplings precision, these results will have to be consolidated in the future by full detector simulation studies including beam induced backgrounds from the muon decays. A comparison between current full simulation results and DELPHES, performed in the H → b b channel [55], displays a reduced precision for the b-jets energy determination. However the resolution degradation does not affect the H → b b cross section measurement precision appreciably, leading to a good agreement between the fast and full simulation estimates in this channel.…”

“…Here we focus on the practical implications [11,[21][22][23][53][54][55] of the collinear emission of nearly on-shell massive vector bosons, which is the analog in the EW context of the Weizsäcker-Williams emission of photons. The vector bosons V participate, as depicted in Figure 5, to a scattering process with a hard scale √ ŝ that is much lower than the muon collision energy E cm .…”

“…ment, without large physics backgrounds from QCD, a 10 TeV muon collider (over-)qualifies as a Higgs factory [22,[54][55][56][57]. Unlike e + e − Higgs factories, a muon collider also produces Higgs pairs copiously, enabling accurate and direct measurements of the Higgs trilinear coupling [21,23,54] and possibly also of the quadrilinear coupling [58].…”

“…In what follows we employ instead the more recent estimates of Ref. [55], that do incorporate physics backgrounds as well as detector effects through the muon collider DELPHES card [245,246].…”

“…Further work is also needed for a robust assessment of the possibility, which we do assume in our estimates [55], to discriminate between the WBF and the ZBF Higgs production channels by tagging very forward muons well beyond |η| ≈ 2.5. This would require a dedicated forward muon detector, as described in Section 4.5, that is still to be designed.…”