Heidelberg 2022 – scientific programme

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T: Fachverband Teilchenphysik

T 62: Higgs Boson: Extended Models 2

T 62.9: Talk

Wednesday, March 23, 2022, 18:15–18:30, T-H21

Search for a light CP-odd Higgs boson decaying into a pair of taus with ATLAS — •Jannik Friese, Tom Kreße, Max Märker, Wolfgang Mader, and Arno Straessner — IKTP, Dresden, Germany

Even though theoretical predictions of the SM are corresponding to experimental results to an incredible degree, there are still some phenomena unexplained, for example the deviation of the measured anomalous magnetic moment, g−2, of the muon from SM calculations. This deviation could be explained by the flavor-aligned two-Higgs-doublet model (2HDM). The introduction of a second Higgs doublet leads to four additional Higgs bosons, one of which being CP-odd and electrically neutral. The muon g−2 deviation is best explained with a light CP-odd Higgs boson which couples nearly exclusively to top quarks and tau leptons. This talk presents the search of such a light CP-odd Higgs boson produced via gluon fusion. The decay into two tau leptons is analyzed by looking at one electron and one muon in the final state. The mass of the light Higgs boson is assumed to be in the range between 40 GeV and 90 GeV. The search is based on 139 fb⁻¹ of data collected by the ATLAS experiment at 13 TeV center of mass energy. Before unblinding the signal region, background control regions are analyzed to verify a good description of the data distributions. In particular, the transverse momentum spectrum of the electrons and muons receives contributions from QCD background which is not modeled well by Monte Carlo simulations. This talk focuses on the estimation of this source of background using a data driven fake-factor method.