Search for the standard model Higgs boson in $ZH\rightarrow ℓ^+ℓ^−b\bar b$ production with the D0 detector in $9.7\ \text{fb}^{ -1}$ of $p\bar p$ collisions at $\sqrt s=1.96\ \text{TeV}$

Abstract

We present a search for the standard model (SM) Higgs boson produced in association with a Z boson in $9.7 \text{fb}^{−1}$ of $p\bar p$ collisions collected with the D0 detector at the Fermilab Tevatron Collider at $\sqrt s=1.96 \text{TeV}$. Selected events contain one reconstructed $Z→e^+e^−\ \text{or}\ Z→μ^+μ^−$ candidate and at least two jets, including at least one jet identified as likely to contain a b quark. To validate the search procedure, we also measure the cross section for $ZZ$ production in the same final state. It is found to be consistent with its SM prediction. We set upper limits on the $ZH$ production cross section times branching ratio for $H→b\bar b$ at the 95% C.L. for Higgs boson masses $90≤M_H≤150 \text{GeV}$. The observed (expected) limit for $M_H=125 \text{GeV}$ is 7.1 (5.1) times the SM cross section.