Higgs self-coupling at the FCC-hh

The Higgs self-coupling 𝜆 governs the shape of the Higgs potential and its precise determination is one of the main goals at future colliders. Here we present a new study based on fast simulations at the FCC-hh, assuming √𝑠 = 100 TeV and an integrated luminosity of 30 ab$^{−1}$. The $𝜅_𝜆$ selfcoupling modifier is determined from double Higgs production in two channels, the 𝑏𝑏𝛾𝛾 and the 𝑏𝑏ℓℓ + 𝐸T𝑚𝑖𝑠𝑠 final states. The 𝑏𝑏𝛾𝛾 drives the precision, down to 3.6%, while the 𝑏𝑏ℓℓ + 𝐸T𝑚𝑖𝑠𝑠 achieves an uncertainty of 22%, however being a benchmark measurement for the impact of pileup. A further study on the resolution of the invariant mass $𝑚_{𝑏𝑏}$ of the two b-jets in 𝑏𝑏𝛾𝛾 shows that, with an optimal calorimeter and b-tagging algorithm achieving a resolution of 3% on $𝑚_{𝑏𝑏}$, a precision ≤ 2% on $𝜅_𝜆$ can be reached.