Search for new particles in an extended Higgs sector with four b quarks in the final state at $\sqrt{s}$ = 13 TeV

The collaboration
Phys.Lett.B 835 (2022) 137566, 2022.

Abstract (data abstract)
A search for an extended Higgs sector, characterized by a massive resonance X decaying to a pair of spin-0 bosons $\phi$ that themselves decay to pairs of bottom quarks, is presented. The analysis is restricted to the mass ranges $m_\phi$ from 25 to 100 GeV and $m_\textrm{X}$ from 1 to 3 TeV. For these mass ranges, the decay products of each $\phi$ boson are expected to merge into a single large-radius jet. Jet substructure and flavor identification techniques are used to identify these jets. The search is based on CERN LHC proton-proton collision data at $\sqrt{s}=13~\mathrm{TeV}$, collected with the CMS detector in 2016--2018, corresponding to an integrated luminosity of $138~\mathrm{fb}^{-1}$. Model-specific limits are set on the product of the production cross section and branching fraction for X~$\to \phi\phi \to (bb)(bb)$ as a function of mass, where both the X~$\to \phi\phi$ and $\phi \to bb$ branching fractions are assumed to be $100\%$. These limits are the first of their kind on this process, ranging between 30 and 1 fb at $95\%$ confidence level for the considered mass ranges.