Abstract
A search for a heavy pseudoscalar Higgs boson, A, decaying to a 125 GeV Higgs boson h and a Z boson is presented. The h boson is identified via its decay to a pair of tau leptons, while the Z boson is identified via its decay to a pair of electrons or muons. The search targets the production of the A boson via the gluon-gluon fusion process, gg → A, and in association with bottom quarks,
$$\text{b}\overline{\text{b}}\text{A }$$
. The analysis uses a data sample corresponding to an integrated luminosity of 138 fb
−1 collected with the CMS detector at the CERN LHC in proton-proton collisions at a centre-of-mass energy of
$$\sqrt{s}=13$$
TeV. Constraints are set on the product of the cross sections of the A production mechanisms and the A → Zh decay branching fraction. The observed (expected) upper limit at 95% confidence level ranges from 0.049 (0.060) pb to 1.02 (0.79) pb for the gg → A process and from 0.053 (0.059) pb to 0.79 (0.61) pb for the
$$\text{b}\overline{\text{b}}\text{A }$$
process in the probed range of the A boson mass, m
A, from 225 GeV to 1 TeV. The results of the search are used to constrain parameters within the
$${\text{M}}_{\text{h},\text{EFT}}^{125}$$
benchmark scenario of the minimal supersymmetric extension of the standard model. Values of tan β below 2.2 are excluded in this scenario at 95% confidence level for all m
A values in the range from 225 to 350 GeV.
