Search for exotic decays of the Higgs boson into bb̅ and missing transverse momentum in pp collisions at √s = 13 TeV with the ATLAS detector

Centre Authors: Barberio, E. L., Jackson, P., Kong, A., McDonald, E., McNamara, P., Potti, H., Ruggeri, T., Scutti, F., Taylor, G., Urquijo, P., White, M.

A search for the exotic decay of the Higgs boson (H) into a bb̅ resonance plus missing transverse momentum is described. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb⁻¹ of pp collisions at $\sqrt{s}$ = 13 TeV. The search targets events from ZH production in an NMSSM scenario where H → ${\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_2^0{\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_1^0$, with ${\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_2^0$ → $a{\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_{\mathrm{}}^0$, where α is a light pseudoscalar Higgs boson and ${\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_{1,2}^0$ are the two lightest neutralinos. The decay of the a boson into a pair of b-quarks results in a peak in the dijet invariant mass distribution. The final-state signature consists of two leptons, two or more jets, at least one of which is identified as originating from a b-quark, and missing transverse momentum. Observations are consistent with Standard Model expectations and upper limits are set on the product of cross section times branching ratio for a three-dimensional scan of the masses of the ${\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_2^0$, ${\stackrel{\sim <!--\; \sim \; -->}{\mathrm{\chi <!--\; \chi \; -->}}}_1^0$ and α boson.

Published: Jan, 2022

DOI: https://doi.org/10.1007/JHEP01(2022)063